Introduction to Structural Drying Manual

Transcription

Introduction to
Structural Drying
Manual
Introduction to Structural Drying
Contents
1
The Changing “State” of Water ................................................................................................................. 5
2
The Drying Pie ............................................................................................................................................ 6
2.1
Factors Influencing the Rate of Evaporation ..................................................................................... 6
2.2
Airflow ............................................................................................................................................... 7
2.3
Humidity ............................................................................................................................................ 7
2.4
Heat ................................................................................................................................................... 8
3
The Drying of Buildings - 3 Phases of Drying ............................................................................................. 9
4
Determining Equipment Requirements .................................................................................................. 10
4.1
Extraction......................................................................................................................................... 10
4.2
Air movement .................................................................................................................................. 11
4.2.1
Different types of air movers:.................................................................................................. 11
4.2.2
To estimate the number of air movers required to start the job using conventional
dehumidification: .................................................................................................................................... 12
4.2.3
Guidelines for placement of air movers using conventional dehumidifiers: .......................... 13
4.2.4
Guidelines for number and placement of air movers using heat drying systems:.................. 13
4.3
Dehumidification ............................................................................................................................. 13
4.3.1
Conventional refrigerant dehumidifiers .................................................................................. 13
4.3.2
Low Grain Refrigerant Dehumidifiers (LGR) ............................................................................ 14
4.3.3
Desiccant Dehumidifiers .......................................................................................................... 15
4.3.4
To estimate the number of dehumidifiers required to start the job: ..................................... 16
4.4
Heat Drying Equipment ................................................................................................................... 17
4.4.1
High Energy Systems................................................................................................................ 17
4.4.2
Convection Systems ................................................................................................................. 19
4.4.3
Drymatic - Drying Intelligence ................................................................................................. 20
4.4.4
Drymatic Boost Box ................................................................................................................. 20
4.4.5
The Drymatic Floor & Wall System .......................................................................................... 21
4.4.6
To estimate the number of Drymatics required to start the job:............................................ 22
4.4.7
Combination Drying Systems................................................................................................... 22
4.4.8
Direct Fired Heating Systems................................................................................................... 22
4.4.9
Thermal Loss ............................................................................................................................ 23
4.5
Page 2
Air Filtration Devices (AFDs) ............................................................................................................ 23
5
6
4.5.1
Guidelines for the quality of AFDs required to be installed: ................................................... 24
4.5.2
AFDs and Heat Drying Equipment ........................................................................................... 24
Target Drying Techniques ........................................................................................................................ 25
5.1
Tenting ............................................................................................................................................. 25
5.2
Direct Air Drying Systems ................................................................................................................ 26
5.3
Side by Side ...................................................................................................................................... 27
5.4
Problems with differential drying .................................................................................................... 29
Monitoring the Drying Regime by Moisture Measurements .................................................................. 30
6.1
6.1.1
Moisture sensors ..................................................................................................................... 30
6.1.2
Non-Penetrating moisture meter ............................................................................................ 30
6.1.3
Penetrating moisture meter .................................................................................................... 31
6.1.4
Thermo-hygrometers .............................................................................................................. 31
6.1.5
Combination Meters................................................................................................................ 31
6.1.6
Data Collection ........................................................................................................................ 31
6.1.7
Thermal Imaging ...................................................................................................................... 32
6.2
7
Recording Readings ......................................................................................................................... 30
Measuring Moisture in Building Materials ...................................................................................... 32
6.2.1
Quantitative Readings ............................................................................................................. 32
6.2.2
Qualitative Readings ................................................................................................................ 32
6.2.3
Dry Standard ............................................................................................................................ 32
6.2.4
Equilibrium Moisture Content (EMC) ...................................................................................... 33
6.2.5
Equilibrium Relative Humidity (ERH) ....................................................................................... 33
The Drymatic System ............................................................................................................................... 34
7.1
Introduction ..................................................................................................................................... 34
7.2
Drymatic Operating Modes ............................................................................................................. 35
7.2.1
Re-circulation Mode ................................................................................................................ 36
7.2.2
Exhaust Mode .......................................................................................................................... 36
7.3
Installation Procedure ..................................................................................................................... 37
7.4
System Set-Up ................................................................................................................................. 38
7.4.1
Step One – Connect Power ...................................................................................................... 38
7.4.2
Step Two – Insert Data Card (skip if not using) ....................................................................... 38
7.4.3
Step Three – Switch On ........................................................................................................... 39
7.4.4
Step Four – Error Code 0000 ................................................................................................... 39
Page 3
8
7.4.5
Step Five – Reset Data Card (skip if not using) ........................................................................ 39
7.4.6
Step Six – Unlock and set dials ................................................................................................ 39
7.4.7
Step Seven – Starting up.......................................................................................................... 39
7.5
Sensor Activation ............................................................................................................................. 40
7.6
SMS Text Messaging ........................................................................................................................ 42
Appendix .................................................................................................................................................. 44
8.1
Page 4
Psychrometric Chart ........................................................................................................................ 45
1 The Changing “State” of Water
Water exists in three states of matter: solid (ice) liquid (water) and gas (steam/vapour). The primary factor
that will ultimately determine what state water will take is the amount of energy each molecule contains.
The more energy each water molecule possesses the more rapidly it can move, so when molecules are
moving quickly enough the chemical attraction that they have to each other is no longer sufficient to hold
them together. As water molecules gain or lose enough energy to create or break the bonds with one
another, then a change of state occurs and these are called “phase changes”.
There are several phase changes that can occur depending upon whether energy is being added or
removed. The actual amount of energy required to change waters state is quite vast, and in fact it requires
more energy during the phase changes to change water from one state to another than is required for
almost any other type of molecule.
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2 The Drying Pie
Humidity, airflow and temperature directly affect the state in which water exists, solid (ice), liquid (water),
or gas (vapour), and the rate in which the change occurs.
Ultimately the goal in restorative drying is to remove excess water from the effected building materials
after a water loss. The process requires restorers to change liquid water into vapour (evaporation). Once
evaporation has occurred the water vapour must be removed from the building. This is traditionally done
by dehumidification, by changing the vapour to water by cooling it. It can also be done by air exchange,
venting the moisture laden air out of the building and bringing in air from outside.
2.1 Factors Influencing the Rate of Evaporation
Concentration of the substance evaporating in the air: If the air already has a high concentration of the
substance evaporating, then the given substance will evaporate more slowly.
Concentration of other substances in the air: If the air is already saturated with other substances, it can
have a lower capacity for the substance evaporating.
Concentration of other substances in the liquid (impurities): If the liquid contains other substances, it will
have a lower capacity for evaporation.
Flow rate of air: This is in part related to the concentration points above. If fresh air is moving over the
substance all the time, then the concentration of the substance in the air is less likely to go up with time,
thus encouraging faster evaporation. This is the result of the boundary layer at the evaporation surface
decreasing with flow velocity, decreasing the diffusion distance in the stagnant layer.
Inter-molecular forces: The stronger the forces keeping the molecules together in the liquid state, the
more energy one must get to escape.
Pressure: Evaporation happens faster if there is less exertion on the surface keeping the molecules from
launching themselves.
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Surface area: A substance which has a larger surface area will evaporate faster as there are more surface
molecules which are able to escape.
Temperature of the substance: If the substance is hotter, then its molecules have a higher average kinetic
energy, and evaporation will be faster.
Density: The higher the density, the slower a liquid evaporates.
2.2 Airflow
Air movers are used to facilitate evaporation by
removing the boundary layer of humid air from around
the wet surface. Air movers rapidly supply dryer air
directly to the wet surface and thereby lowering the
vapour pressure at the surface which facilitates faster evaporation.
The more moisture a material contains the faster the water will evaporate. When using air movers alone
greater evaporation rates require more airflow to maintain the lower vapour pressure across the surface.
As materials dry less air flow is required. WHY?
Road block - The practice of trying to create sufficient low vapour pressure around
wet materials to release the bound water in a material has meant that massive
amounts of air movement has been utilised to aid the required evaporation,
unfortunately the use of large amounts of air movement creates two problems.
Air movement creates thermal loss (cools down). Cooler air and cooler surface
materials means that less energy is transferred to the moisture molecules which does not give them the
sufficient energy to make the phase change required to escape the material.
Large quantities of air movers create a lot of heat energy (BTUs). In theory the heat created by the air
movers aids in the drying process as the heat energy is transferred to the water molecules and surfaces
giving the energy required to make the phase change. The problem with excess heat is that often the BTUs
created by the air movers can generate temperatures that are outside of the efficient operating ranges of
refrigerant dehumidifiers.
2.3 Humidity
Air movement is used to create evaporation. Air will hold a limited amount of moisture before the air
becomes saturated and cannot hold any more moisture (referred to as dew point). Dehumidification is
used to remove moisture from the air lowering the vapour pressure, so that the equipment used to create
air movement, can continue to facilitate moisture evaporating from the wet structure or contents.
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Road block – Limiting the temperature to the limitations of the dehumidifier hinders
the evaporation rate. In the beginning of the job where there is high humidity the
dehumidifier is effective at removing water. By raising the temperature, relative
humidity is reduced, increasing the ability of the air to hold more moisture. (Increasing
thirst). But above 32 degrees the dehumidifier does not have enough capacity to
reduce the temperature of the incoming air to dew point hence condensation on the
dehumidifier coils.
Large amounts of air movement equipment required to encourage evaporation often used on water losses
can raise the temperature of the air above the most effective operating temperature of dehumidifiers.
As the amount of water in the structure decreases and the vapour pressure becomes lower the efficiency of
the dehumidifier is also reduced in the same way. Lowering the temperature of the incoming air closer to
20 degrees towards the end of the job ensures the dehumidifier can achieve the required temperature
drop to achieve dew point.
But it is in this phase of the drying process that additional energy in the form of heat can vastly accelerate
the drying process.
Common ways to control temperatures in drying situations is to use the building air conditioning system,
install portable air conditioning systems, reduce or increase the amount of air movers or temporarily use
cooler air from outside the structure (commonly called burping). Another way is to use a controlled heating
drying system to control heat and humidity ….. Drymatic.
2.4 Heat
Temperature in the form of heat energy is often overlooked in the drying process but is one of the key
factors in “drying science”. In brief the two main conclusions that can be drawn from research is that at the
beginning of the drying process where there is a lot of free water not bound in the materials, a 10°C
temperature increase causes a doubling of the evaporative rate. (Equivalent to doubling the amount of air
movers). Following this towards the end of the process where evaporation is decreased due to water being
bound in the materials the terminal drying rate increases rapidly with increases in temperature. Heat gives
the water the energy required to make the phase change from water to vapour.
Road block – Simply heating up the structure with heaters ensures vastly faster
evaporation rates. Uncontrolled heat and fast evaporation can lead to overdying,
differential or drying to0 fast. Until now the knowledge and technology required to
understand how much heat and how to control it has not been available. Drymatic!
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3 The Drying of Buildings - 3 Phases of
Drying
3 Phases of Drying
Q l/day
Phase 1 is a critical point – failure to
mitigate at this phase will increase
drying times at phase 3
Phase 1
Phase 2
The drying system at phase 2 may
not be correct for phase 3
Phase 3
Time
Removal of
liquid water
Surface drying
Drying of material
Phase 1 - Removal of Liquid Water - Extraction
Effective removal of standing water will significantly affect the amount of drying equipment and the time
required to return the building and contents to equilibrium moisture content. Effective extraction will also
ensure less destructive methods of restoration are required.
Phase 2 - Surface Drying
Surface drying of carpet underlay and surface water from building materials such as timber and concrete.
Phase 3 – Drying of Structural Materials
Drying of water bound in materials. To assist in the third phase of drying of water damage property,
knowledge of how materials dry is of great importance and how the drying actually takes place within a
building. Different methods, knowledge and tools are required to get the energy required to the bound
water to ensure phase change.
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4 Determining Equipment Requirements
4.1 Extraction
Effective removal of standing water will significantly affect the amount of drying equipment and the time
required to return the building and contents to equilibrium moisture content. Effective extraction will also
ensure less destructive methods of restoration are required.
Vacuum equipment is recommended for standing water extraction. The greater the
air flow and vacuum pressure, the more effective that equipment will be.
Truckmounted equipment has significantly higher airflow and vacuum pressure than
portable extraction equipment and generally is more effective in removal of standing
water. Specialised portable flood extraction equipment that uses shorter hose lengths
and larger diameter hoses (2 inch) can be effective.
Portable equipment exhaust air should be vented outside of the building. Portable equipment exhausts air
from the vacuum blowers into the surrounding environment. When extracting contaminated water in
category three drying situations consideration should be taken as to the position of the machine to prevent
spread of contaminants.
Small vacuums such as shop vacs or wet vacs and domestic vacuums do not provide adequate power for
effective extraction.
There are various extraction tools that can be used in conjunction with vacuum equipment that will
improve the effectiveness of water extraction.
A weighted compression can use heavy weights or as a stand on machine
and works on the principle of extracting/pushing the water out of the
underlay through the carpet and into the extraction machine. This tool
allows greater water removal with the same vacuum equipment than
many other extraction tools.
A vacuum sealed (water claw or equivalent) can be used with truckmount
and portable extraction equipment. As the vacuum sealed tool requires water to create the vacuum seal it
is recommended to first extract with the tool to remove as much water as possible from the underlay prior
to completing extraction with a conventional carpet cleaning wand.
A conventional carpet cleaning wand is not efficient at removal of water from carpet underlay. Where
specialised extraction tools such as weighted compression or vacuum sealed tools are not utilised it is
recommended the carpet underlay is removed. A conventional carpet cleaning wand is effective for
extraction of standing water from direct stick commercial carpets.
An extraction test to gauge the effectiveness of extraction on carpet is recommended. After extraction, lift
a small section of carpet and ‘wring’ the underlay to see if there is any dripping wate. If so, a further
extraction will be required.
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Specialised extraction tools such as hard floor squeegee wands and hardwood
floor drying mats are recommended for effective removal of standing water
from structural components such as hardwood flooring.
To ensure adequate extraction from hardwood flooring it is recommended to
install wood floor panels and attach them to a truck mount or portable flood
extractor for approximately 1 hour prior to installation of the high pressure low
volume vacuum system (Injectidry, interair). This process ensures as much of
the standing water from below and from between the boards is removed prior
to beginning the process of attempting to remove the bound water.
4.2 Air movement
Air movers are used to facilitate evaporation by removing the boundary layer of humid air from around the
wet surface. Air movers rapidly supply dryer air directly to the wet surface and thereby lowering the vapour
pressure at the surface which facilitates faster evaporation. Secondly air movers are used to manage air
movement around the structure. Air management eliminates the need to use dehumidifiers, heat drying
equipment and air filtration devices in all affected areas and can be used to manage air pressure, humidity,
and temperature or air quality.
4.2.1
Different types of air movers:
Traditional carpet dryer air movers are commonly referred to as air movers or blowers. A
traditional carpet dryer is a snail shell type centrifugal blower with a minimum of a 3/4 hp
motor. Air movers have the most static pressure. Static pressure is used by air movers to
lift carpet, to place an air mover under carpet and push the carpet up to generate air flow
under the carpet or with the use of accessories can be used to duct air into small spaces
such as wall cavities and under cabinets and under hardwood flooring.
Low amp air movers are a snail shell type centrifugal blower that uses motors smaller
than ¾ hp. Low amp air movers generate lower air movement and lower static
pressure. The advantage of using low amp air movers is that more air movers can be
used on one circuit whilst generating large volumes of CFM and generating less heat
than traditional carpet dryer air movers. Low amp air movers are typically used with
less destructive restoration processes, where excess heat generation will affect the
performance of dehumidifiers and where power supplies are limited.
Low pressure axial fans are specialised air movers used to move large volumes of air
with lower amp draw. Low pressure axial fans are efficient for drying long surfaces
open areas and carpets. Because of their low pressure they are not useful for pushing
air into cavities and through duct work. The advantage of using axial fans is they can
deliver large volumes of laminar airflow whilst using much less power and generating
much less heat. Low amp air mover are typically used with less destructive
restoration processes, where excess heat generation will effect the performance of
dehumidifiers and where power supplies are limited.
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High pressure ventilating fans are used with ducting to move large volumes of air.
Ventilating fans can be used to generate strong positive or negative air pressures,
and can be used to manage air pressure, humidity, temperature or quality.
Specialty air movement equipment air mover
adaptors and low volume high pressure air
movement systems can be used to inject air flow
under cabinets, into wall and ceiling cavities and
under hardwood flooring.
Low Volume High Pressure Air
Movement systems (Interair Drying
Systems or Intectitdry) are used
when more pressure is needed but air volume is less important. They
can be setup in either positive pressure or negative pressure modes
and are used to dry cavities such as under cabinets, wall cavities and
under hardwood flooring. LVHP systems typically move
approximately 100 CFM and produce up to 60 inches of static
pressure (standard air mover typically produces 2-3 inches of static
pressure). Since cavities have a small volume of air space the low CFM of the unit is effective in drying.
Pressure is the main focus of the system. A large amount of pressure is required to push or pull air through
lengths of tubing, through walls or other cavities or pull air through floor board cracks and crevices.
Direct air drying systems and heat boosters: By using
specialised Direct Air Drying wall and floor systems, a
constant warm air stream can be directed at wet surfaces.
The warm air stream will quickly remove the boundary layer
and promote fast and efficient evaporation.
4.2.2
To estimate the number of air movers required to start the job using
conventional dehumidification:
1. Determine the number of square metres of the effected area
2. Determine the class of the loss
3. Divide the square metres by the factors as follows
• Class 1: divided the square metres by 14, then divide square metres by 28
• Class 2 or Class 3: divide the square metres by 4.6, then divide square meters by 5.6
4. The resulting number is the minimum range of air movers needed
5. Additional airflow may be required for offsets such as closets and bay windows
6. Speciality air movers may be required if sub surfaces require air flow
7. The number of air movers may need to be increased or decreased through out the drying process
based on changes in the psychrometric readings and moisture readings.
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4.2.3
Guidelines for placement of air movers using conventional
dehumidifiers:
1. In a class 2 or class 3 water loss air movers are placed every 3 – 4 metres along the wall
2. Air mover are placed at a 15 to 45 degree angle facing the wall depending on the type of air mover
3. Air mover snout should almost touch the wall, which means within 2 – 3 cm off the wall but not
touching it
4. All air movers in each area will face the same direction, whether clockwise or counter clockwise, to
ensure that air movers are creating a cyclone effect and not pushing against each other
5. The positioning of air movers may need to be altered throughout the drying process based on
changes in the psychrometric readings and moisture readings.
4.2.4
Guidelines for number and placement of air movers using heat drying
systems:
Minimal air movement is required with the use of heat drying equipment. Typically you need just enough
air movement to ensure warm air is circulated evenly around the structure. For high energy systems air
movement must be enough to adequately ventilate the wet air from the building.
4.3 Dehumidification
Air movement and heat is used to create evaporation. Air will hold a limited amount of moisture before
the air becomes saturated and cannot hold any more moisture (referred to as dew point).
Dehumidification is used to remove moisture from the air so that the equipment, used to create air
movement, can continue to facilitate moisture evaporating from the wet structure or contents.
Dehumidifiers are used to remove moisture from the air to create a balanced drying system. A balanced
drying system is achieved when the rate of dehumidification exceeds the rate of evaporation. Where the
rate of evaporation exceeds the rate of dehumidification excess moisture can cause secondary damage
such as mould.
4.3.1
Conventional refrigerant dehumidifiers
Conventional refrigerant dehumidifiers operate in much the same way an air
conditioner works. Filtered incoming air is directed across cold evaporator
coils causing the air temperature to reach dew point and cause moisture to
condense on the coils. The condensed water is collected and purged from
dehumidifier. The air is then passed across a warm condenser coil where the
dehumidifier purges waste heat. The air exhausted from the dehumidifier is
heated by the warm condenser coil making the exhausted air able to hold
more moisture (thirst). Conventional refrigerant dehumidifiers work most
efficiently with air temperatures between 18 and 32 degrees and will achieve
a minimum specific humidity of 65 grains per pound. Conventional refrigerant
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dehumidifiers are primarily used for class 1 water loss situations such as drying wet carpet and underlay.
Conventional dehumidifiers perform very well for class 1 water loss situations but are not suitable for
drying structural building materials.
4.3.2
Low Grain Refrigerant Dehumidifiers (LGR)
Low grain refrigerant dehumidifiers (LGR) achieve higher efficiency by incorporating a pre cooling stage
which provides the dehumidifier with precooled air to process. Precooling the air makes it easier for the air
passing across the cold coil to reach dew point. This results in a more energy efficient system with
increased performance and enables a broader temperature efficiency range. As with conventional
refrigerant dehumidifiers LGR dehumidifiers work most efficiently with air temperatures between 18 and
32 degrees but will achieve a minimum specific humidity of 35 grains per pound. Due to higher efficiency,
increased temperature operating efficiency and ability to achieve lower specific humidly LGRs are
recommend for most water loss situations including drying of some more porous structural components.
Conventional and LGR Dehumidifier (all brands all makes and
models) performance can be improved by managing air
temperatures. Higher temperature with a maximum temperature
of 30 degrees is optimal at the beginning of the job where high
humidity exists; gradually lowering temperatures to a minimum
of 20 degrees is optimal towards the end of the job where lower
humidity exists.
Common ways to control excess temperatures in drying situations
is to use the building air conditioning system, install portable air
conditioning systems or temporarily use cooler air from outside
the structure (commonly called burping). Where additional heat
is required to increase temperature thermostat controlled
convection heat dry systems such as Drymatic can be used.
Conventional and LGR Dehumidifiers come in various capacities.
In order to determine one dehumidifier’s performance against
another, most professional equipment is independently tested
and is given an AHAM rating (American Home Appliance
Manufactures). Performance of the dehumidifier is tested in
constant conditions of 26.7 degrees, 80% relative humidity over a
24 hour period. Performance of the dehumidifier is expressed as
water removal in litres per day.
(When comparing dehumidifier capacity and performance look at the AHAM
rating not the total daily capacity, plus look at the performance of the
dehumidifier in LGR condition of specific humidity of35 – 40 gpp)
Page 14
4.3.3
Desiccant Dehumidifiers
Desiccant dehumidifiers use a special humidity absorbing material called a desiccant. Intake air (referred to
as process air) is passed over the desiccant material which absorbs the moisture. Usually 75% of the
process air exits the dehumidifier as warm dry air (process air). The remaining 25% is heated and passed
across the wet desiccant material to dry the material (reactivation air). The reactivation air takes on the
moisture and is exhausted as warm wet air. The warm water is either vented from the structure or cooled
and condensed and purged as water. Desiccant dehumidifiers work more efficiently when the process air is
cool and dry.
As usually only 75% of the process air is returned to the structure negative air pressure is usually created in
the structure. Care must be taken to ensure the quality of the makeup air (25%) entering the structure.
Desiccant dehumidifiers can achieve a very low specific humidity of 10 grains per pound and are particularly
efficient at drying structural components such as hard wood floors and wall cavities.
Desiccant dehumidifiers can be smaller portable electric units or larger more powerful trailer mounted
units that have onboard generators and use either LPG or diesel to generate the heat source for
reactivation. Larger trailer mounted units are often used for drying of larger commercial buildings. Capacity
of desiccant dehumidifiers is expressed in the volume of air that can be processed per hour either, cubic
feet per minute (CFM) or, cubic metres per hour (CMH) of the process air exiting the dehumidifier.
High volume desiccant dehumidifiers are very good at structural drying as generally they produce large
volumes of warm dry air.
Page 15
4.3.4
To estimate the number of dehumidifiers required to start the job:
1. Determine volume of air to be dehumidified by multiplying the length x width x height (L x W x H)
2. Note the capacity of the dehumidifiers being used expressed as AHAM litres per day rating of the
refrigerant/LGR dehumidifier(s) being used, or the process air out cubic metres per hour (CMH) of
the desiccant.
3. Determine the classification of water loss, or the initial rate of evaporation based on type of wet
materials and the degree of water incursion (Class 1, Class 2, Class 3 or Class 4)
4. Use the following Dehumidification Factor Table to determine the litres per day or the CMH required
to start the job
Class 1
Class 2
Class 3
Class 4
Units
Conventional
Refrigerant
6
2.4
1.8
N/A
Cubic meters per
litre
LGR
6
3
2.8
3
Cubic meters per
litre
Desiccant
1
2
3
2
Air exchanges per
hour
5. Once all factors are known use the following formulas:
•
Refrigerant/LGR - Cubic meters/Dehumidification factor = AHAM Litres required,
Divide the AHAM litres required by the AHAM litres of the units to be installed to get the
minimum number of units required (round up)
•
Desiccant – Cubic metres x Dehumidification factor = CMH required
Divide the CMH required by the CMH of the process out air of the units to be installed to get
the minimum number of units required (round up)
6. Dehumidification factors are intended as a guide for initial installation of the minimum
dehumidification equipment required to ensure dehumidification exceeds evaporation, i.e. a
balanced drying system is in place.
7. After initial setup dehumidification may need to be increased or decreased based on changes in the
psyrchometric readings and moisture readings.
8. Relative humidity should not linger above 60% for any length of time. With adequate extraction
relative humidity of 40% or below should be achieved within the first 24 hours.
Page 16
4.4 Heat Drying Equipment
Temperature in the form of heat energy is often overlooked in the drying process but is one of the key
factors in “drying science”. In brief the two main conclusions that can be drawn from research is that at the
beginning of the drying process where there is a lot of free water not bound in the materials, a 10°C
temperature increase causes a doubling of the evaporative rate. Following this towards the end of the
process where evaporation is decreased due to water being bound in the materials the terminal drying rate
increases rapidly with increases in temperature. 1
The installation of air moving and dehumidification equipment in phase 3 of the drying regime will continue
to assist in the evaporation of the surface and subsurface moisture, however the use of air movers and
dehumidifiers alone have limited ability to decrease the drying times of structural building materials where
water is bound in difficult to dry wet hardwood, concrete, tile and brickwork. Introducing heat energy and
better interaction of the equipment and using target drying attachments increases the efficiency of
standard drying equipment. Hence, drying times can be significantly reduced.
4.4.1
High Energy Systems
The High Energy Systems use an external source
of heat equipment which operates by heating
outside air over ceramic plates or in ovens,
which are heated by using propane/butane or
glycol fuel sources. This air may also be passed
through desiccant dehumidification equipment
prior to or post heating. The air is then driven
into the building by fans which can be part of the
heating equipment or added to the equipment
within the building either as part of the heat
exchanger equipment or in isolation to increase
airflow through the building.
1 C. Hall, W. D. Hoff M. R. Nixon, Water Movement in Porous Building Materials‐‐VI. Evaporation and Drying in Brick and Block Materials; Building and
Environment, Vol. 19, No. 1, pp. 13 20, 1984
Page 17
In essence the system is used to create a very hot environment in the building which allows for a faster
evaporation process as the lower vapour pressure within this hot air stream generates faster evaporation
within the higher vapour pressured materials, and a “moisture flushing“ system is in operation.
This system requires more consistent monitoring to stop excessive drying taking place plus there can be
thermal stress on the surface of delicate materials due to the low specific humidity of the air passing over
the surface creating fast surface drying without transfer of energy to the moisture within the material.
High energy systems are particularly good for drying subfloors. When drying sub floors with high energy
systems the air movement out of the sub floor area must exceed the air movement into the sub floor area
to ensure negative air pressure in the space. This is done to ensure no cross contamination of the rest of
the building from air borne particulate or contaminants from within the sub floor area. When using high
energy systems to heat the inside the building the air movement used to “flush” the structure should be
enough to create neutral or slightly positive air pressure. Thermostat controls to turn air movers on and off
work well in this application.
Dri-Eaz Dragon Trailer Mounted
Page 18
4.4.2
Convection Systems
Convection Systems heat air by electrical element or by heat
exchange systems which usually use a heated glycol solution.
Convection systems gradually increase the temperature of the
room increasing the ability of the air to hold more moisture
allowing faster evaporation. They also gradually heat the surfaces
and materials that are wet, which in turn increases the rate of
evaporation. Heating elements fuelled by electricity and are less
expensive to run than the high energy or heat exchange systems.
In a convection heater, the heated electrical element or Glycol heated heat exchange system, heats the air
next to it by convection which is dry heat. Hot dry air is less dense than cool air, so it rises due to buoyancy,
allowing more cool air to flow in to take its place. This sets up a constant current of hot dry air that leaves
the appliance by fans through vent holes and heats up the surrounding space and also heats up the
surfaces and materials that are wet. They are ideally suited for heating a enclosed spaces. They operate by
relative humidity and temperature pre-settings and have a lower risk of ignition hazard. This system is a
good choice for long periods of time and can be left unattended.
Heating up the air within the room increase the ability of that air to allow more evaporated moisture into it
by reducing its relative humidity, however as the relative humidity in the air increases this wet air has to
beremoved and be replaced with drier air or the air would reach saturation and there would be equilibrium
of vapour pressure and possible condensation. The systems use an air exchanging method, where the warm
wet air in the room is periodically flushed to the outside and pre heated fresh air from outside or
preconditioned drier air from unaffected areas is pumped in to replace it.
Air exchange method
• Water vapour pressure dynamics
– Moves low VP to Hot Low VP
– Moves Hot low VP to High VP and dumps it outside
High
VP
Low
VP
Page 19
Low
VP
High
VP
4.4.3
Drymatic - Drying Intelligence
The Drymatic’s unique operation is based upon it’s evaluation of the humidity and temperature of the
room to be dried and then operating in the mode that provides maximum drying effect.
When initially switched on, the machine operates in ‘re-circulation’ mode, taking air from within the room
being dried and continually re-heating it until pre-set temperature and humidity levels have been reached.
These settings can either be determined by the technician or the default settings of the machine.
It then switches automatically to ‘exhaust mode’, where powerful internal fans extract the air from the
room, replacing it with an equal amount of fresh and pre-heated air from an unaffected area (which is
generally indoors) to ensure an on-going optimised drying environment.
Adding controlled heat to the environment speeds up the drying process by promoting evaporation of
moisture from the wet structure and contents. Increasing the ambient temperature allows the air to take
on a higher water vapour content, which is then removed out of the property.
Within limits defined by the user, the Drymatic will monitor and adjust the room’s environment, constantly
optimising and exchanging the moist air with warm, dry air in a controlled manner to remove odours and
ensure a faster, fresher and more efficient drying environment.
Sensors can be used to specify a drying goal based on a known ‘dry’ material ensuring that the property is
not over-dried or under-dried. The infra-Red sensors communicate with the machine and enable the user
to track the progress of specific walls/floors/ceilings within a room.
Optional On-Board SMS Text Messaging Facility can communicate with a drying technician to notify them of
any important events during the job such as the ones below:
4.4.4
Drymatic Boost Box
The Drymatic system has been enhanced with the research and
production of the Drymatic boost box
The Boost box has the same drying intelligence as its big brother the
Drymatic and a 2 kilowatt heating system that “steps” up. This means that it gradually reaches its set
temperature over a set period of time depending on which setting it is on
Page 20
The uniqueness of the Boost box is that it has been designed to use in line with existing air moving
equipment and dehumidifiers, either as a standalone heating system, as an external boost for the Drymatic
or to heat up the air entering a Drymatic Floor & Wall System, and the operating dial is set with these
settings:
•
DADs system - maximum 30 degrees, (works at this temperature setting in conjunction with
dehumidifiers at the beginning of the drying process)
•
Boost for dramatic - maximum 40 degrees,
•
Auxiliary heater - maximum 50 degrees.
Also the 10 amp system allows the use of an airmover on standard domestic electrical circuits without
causing any problems. In fact the system is designed to plug the airmover into the boost box, so that the
intelligent drying system can switch the airmover on and off as required.
The Boost box is installed with
4 sensor plug sockets so that
RH% sensor can be used. One
of the sensor sockets is for a
control measurement ; the
other 3 are for sensors to be
placed in the wet areas.
4.4.5
The Drymatic Floor & Wall System
The Drymatic Floor & Wall System is another
additional piece of equipment to use with the
Drymatic system as it allows hot air to be directed
onto the surface of a wet material and this air
turbulence prevents the build up of a static
boundary layer and therefore increases the
evaporation rate of the material.
The “system” can be either inflated by standard airmovers and using the hot air generated by the
Drymatic into the intake of the air-mover or by the
Drymatic “Boost box” in-line with a standard air
mover.
The versatility of the Drymatic Floor & Wall System
allows for target drying to surfaces with the
addition of thermal energy (heat) being directed
onto those wet areas, thus increasing evaporation.
Page 21
4.4.6
To estimate the number of Drymatics required to start the job:
1. As a general rule of thumb, depending on the amount of moisture present in the structure, and the
potential for thermal loss. Determine the number of large LGR dehumidifiers required to start the
job from the Dehumidification Factor Table above and divide by three.
2. The calculation gives you the number of Drymatic systems required; add boost boxes and drying
mats to compensate for wetter materials and thermal loss or to target dry wetter areas.
3. Install minimal air movers to ensure adequate circulation of warm air through the structure. The
circulation of air coming in and out of the Drymatic is typically enough for most rooms.
4.4.7
Combination Drying Systems
Combination Drying Systems can be used to enhance performance of heat drying systems.
Dehumidification can be used to precondition air from an unaffected area prior to heating or, dehumidifiers
can be used in effected areas in initial stages of drying provided the temperature of the air within the
structure is controlled and does not exceed the effective operating range of the dehumidifier (maximum 32
degrees).
Advanced heat drying systems monitor temperature and humidity. When the air reaches the pre-set
temperature or relative humidity set on the machine, warm wet air is flushed from the environment and
replaced with heated air from outside or preconditioned heated air from an unaffected area.
Systems that do not have pre-set temperature or humidity controls are required to be set up with air
movement to continually flush hot wet air from the building or air movers that are thermostatically
controlled to flush warm wet air from the building.
Less air movement is required when using heat drying systems. Evaporation created by larger amounts of
air movement directed across a wet surface causes thermal loss. Typically air movement used in heat
drying is used to gently circulate warm air around the structure and heat wet surfaces.
4.4.8
Direct Fired Heating Systems
Direct fired heating systems, such as direct fired LPG burners are not recommended. Heat exchanger
systems ensure combustion by-products and moisture created by burning fuels are separated from the
heated air used to dry the structure.
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4.4.9
Thermal Loss
Setting up heat drying systems can at times be a bit more
complex than traditional drying using dehumidifiers and air
movers. Many water loss situations require thought about
how the system should be set up to ensure maximum
efficiency.
Target heating a smaller area is much more efficient than
attempting to heat up the whole structure. The use of
tenting or containment to contain the heat to only areas
that are wet will greatly improve the efficiency of the heat
drying system.
Particular care must be taken to evaluate where heat can be lost from the drying envelope. A lot of heat
can be lost from large amount of wet contents and surfaces such as large uninsulated glass doors and
windows. Tiled bathrooms that are not wet should be isolated.
4.5 Air Filtration Devices (AFDs)
Air filtration devices (AFDs) are commonly referred to as air
scrubbers, negative air machines or HEPA filters. Large volumes of
air movement used to create evaporation create high levels of air
borne particulates and possible contaminants reducing the air
quality of the indoor environment.
Occupants and contractors are at risk of significant discomfort from
the reduced air quality. This is particularly the case where occupants
are very young, elderly, have respiratory illnesses such as asthma, or
are immune compromised. In these cases AFDs are required.
A number of filters are employed in an AFD. A stage one and/or a
stage two pre-filter is required to remove larger particulate and
protect the primary filter prolonging its effective life. It is
recommended to change the pre-filter after each job or when visibly soiled.
It is recommended to use an AFD where the primary filter is a HEPA media (high efficacy particulate air).
HEPA filters are designed to capture 99.97% of particulate down to a size of 0.3 microns. HEPA filters are
required to be replaced as they become saturated and their efficiency becomes compromised. Most AFDs
have an indicator light installed to alert the user when the HEPA filer is required to be replaced. In cases of
a category 3 water loss where there is gross contamination or mould present the HEPA filter is required to
be changed after each job.
Carbon or odour adsorbing material filters can be used to reduce odours and VOCs (volatile organic
compounds) or MVOCs (microbial volatile organic compounds) often found in water loss situations.
Particular care must be taken when changing filters to ensure the safety of the user and occupants to avoid
potential contamination of the indoor environment.
Page 23
AFDs can be used to manage air pressure on water loss situations where there is potential to spread
possible contaminants such as mould and bacteria. Isolating areas and creating negative air pressure in
areas that are potentially contaminated is required.
AFDs are rated in independent standardised testing by AHAM similar to those used for dehumidifiers. CADR
(clean air delivery rate) is expressed in CFM or CMH and is the amount of actual clean air delivered by the
unit after filtration.
4.5.1
Guidelines for the quality of AFDs required to be installed:
1. Determine volume of air to be filtered by multiplying the length x width x height (L x W x H)
2. Determine the number or air exchanges per hour (AEH) required (ranging from 4 to 10 air changes
per hour depending on the level of contamination)
3. Use the following formula to determine the CADR necessary
• Cubic Metres x AEH = CMH/CADR
Divide the CADR required by the CADR of the AFDs to be used to get the minimum number of
units required (round up)
4.5.2
AFDs and Heat Drying Equipment
An additional benefit to using heat drying equipment is that they exchange moisture laden air with fresh air
from outside the structure or preconditioned air from an unaffected area. The process of air exchanges
greatly increases the quality of air within the structure.
Page 24
5 Target Drying Techniques
5.1 Tenting
Target drying is an alternative method of decreasing the drying time in phase 3 of the drying regime. To
carry out target drying trained drying technicians use dry and or hot air, delivered under a polythene
envelope to create a microclimate on the surface of the damp material, (sometimes referred to as
’enveloping’ or ‘tenting’).
Tenting - floors
• Warm air blowing under polythene
• Low vapour pressure, high temperature
Evaporating moisture
Trapped moisture
Page 25
Another method of targeting air directly onto a surface is via specially designed mats that use a process of
impingement drying and air directed on to the surface is more effective than air blown across the surface.
The main reason for the improved effectiveness is considered to be that the turbulence prevents the build
up of a static boundary layer that can insulate the surface from the drying medium.
5.2 Direct Air Drying Systems
Direct Air Drying Systems
Direct Air Drying Mats come in a wide range
of shapes and sizes to suit different drying
situations
They can also be
adapted to assist in
complicated drying
scenarios
Page 26
By using a boost box and dehumidifiers to create hot low vapour pressure in a tent, moisture within a
material which is under high vapour pressure can be drawn towards that area of lower vapour pressure,
and thus drying areas that are inaccessible due to being trapped under or behind materials of low
permeance, can be attempted without the need for the demolition of the those covering materials.
5.3 Side by Side
By using specialised Direct Air Drying wall systems, a constant hot air stream can be directed at a wet wall
to which the impingement method of the air stream will quickly remove the boundary layer and promote
fast and efficient evaporation
Other specialist equipment is available that will deliver air through small holes into building voids to release
trapped moisture or plates that either force air into the surface or suck the moisture laden air out of the
voids. These can be useful for drying behind plasterboard or panelling. This injection drying or plate can
avoid costly and destructive structural dismantling that would otherwise be required to open up some
building parts to release trapped moisture.
High-pressure suction low volume air movers can deliver very high suction and these can be useful for
extracting moisture from beneath flooring or within walls.
Page 27
The input air for the system could either be ambient air from
the room or air directly from a dehumidifier, especially a
desiccant, or hot air from a convection heating system.
Alternatively adaptors to fans can allow air to be forced
behind panelling through gaps or purpose drilled holes,
often after removal of skirting boards.
Other types of equipment can be used to assist drying such
as infrared heaters, indirect heaters, ceramic plate heaters
and microwave heaters.
Superfast drying can be achieved in certain circumstances by
using very high volumes of hot moving air at low relative
humidity. This system heats the air and adds heat energy to
the building materials to speed the evaporation of moisture.
This system can be very useful with severely saturated
buildings. The advantage of heat is that it speeds drying by
replacing the heat lost as a result of evaporation.
This is known as the latent heat of vaporisation.
Page 28
5.4 Problems with differential drying
Problems can arise where wood is dried from one side only, as this can sometimes cause distortion to
occur.
An example is when a wooden floor or wood panelling is dried from the surface only. At first the surface
becomes dry and the underside remains damp. The surface shrinks and the underside remains swollen,
causing the boards to dip or “cup” in the centre.
Often this will flatten when the whole board dries, but sometimes this distortion will be permanent, ruining
the item and requiring replacement.
This problem can be avoided by introducing dry air to both sides of the material to even up the process.
Page 29
6 Monitoring the Drying Regime by Moisture
Measurements
Monitoring the effects of the drying regime are important not only to ascertain when the building is in a
condition of dryness, but to also check the effectiveness of the drying regime in place, and it is best practise
that if the monitoring results establish that the drying regime installed is not assisting the building to a
condition of dryness efficiently, then the regime should be reviewed and possibly changed
The time between monitoring a building will vary dependent on the type of building and amount of
moisture within it, and this time scale should be included in the scope or initial report.
6.1 Recording Readings
Moisture readings must be recorded on a drying plan or moisture measurement sheet and the comparison
control readings/drying goals/drying targets which are also recorded on the same document should be
periodically checked during the time frame of the drying of the building.
It is best practise to take readings on each visit from the same chosen places within the building on the
building materials being dried and the recorded documentation should clearly show where within the
building the readings are being continuously taken.
Time lapse between monitor visits should be agreed during the stabilisation visit, as each building and type
of ingress vary greatly, as do the drying regimes installed at phase 3 of the drying of the building. But it is
best practise that the follow up monitor visit to take moisture readings directly after the initial readings
taken at the stabilisation phase should be within 3-5 days and at that visit a review of the climate control
should be taken.
6.1.1
Moisture sensors
Moisture sensors are the most basic of moisture meters. They have no display and sounds an audible alarm
whenever there is elevated moisture content. A useful tool designed to determine and map the extent of
moisture in carpet only.
6.1.2
Non-Penetrating moisture meter
Non-penetrating moisture meters use capacitance technology to detect moisture. The sensor pad, which
makes surface contact with the material, sends a radio frequency signal into the material. This technology
allows for the operator to assess the overall moisture condition quickly, and with no damage to the
material being tested. The primary disadvantage of a pin-less meter is that of the depth of penetration is
limited to approximately 6mm to 20mm. Surface moisture will also affect the readings to some degree. A
range of Non-penetrating moisture meters are available with some models calibrated to timber,
plasterboard, concrete and a reference scale.
Page 30
6.1.3
Penetrating moisture meter
Penetrating meters operate on the principle of electrical resistance (conductivity). They require the
operator to penetrate the material being tested. The electrical resistance of the material between the pins
is influenced by the presence of moisture and is measured and displayed by the meter. Pin type meters
provide more definitive information on the overall condition of a structure than pinless meters.
By using insulated pins readings can be taken at different depths of penetration, ultimately finding the
source of moisture. Pinless meters are calibrated to timber, plasterboard, paper and a reference scale. The
down side of using pin meters is damage to the material being tested.
6.1.4
Thermo-hygrometers
Thermo-hygrometers are used to determine the temperature and relative humidity of the atmosphere.
These readings allow the operator to calculate specific humidity and dew point. Some models have
additional features that include specific humidity, dew point and vapour pressure. The primary use of the
thermo - hygrometer is to ensure drying conditions have been met and that the equipment used in the
drying process is performing adequately.
Thermo-hygrometers can also be used to determine the moisture in concrete. A hole is drilled in the
concrete and a plastic sleeve inserted. After 48 hours a sensor is inserted into the sleeve and the relative
humidity reading taken.
6.1.5
Combination Meters
Moisture meter technology continues to evolve as we see the combination of pin and pin-less and thermohygrometers into a single meter. Upon arriving at the job the operator can quickly scan the area using the
pin-less function. Then, based on those findings, can go back and use the pins, plus electrodes in the
troubled areas to obtain more precise information. This combines the speed and ease of a pinless meter
with the precision of a pin type meter.
In addition to the different technology, many moisture meters available today also offer some great
features such as built in wood species corrections, a relative scale that provides a “dry to wet” comparison
of moisture non-wood building materials, and a third scale that reads %MC on plasterboard. Meters that
offer these three scales are truly versatile for a wide variety of contractors.
6.1.6
Data Collection
The most advanced meters offer data collection capabilities that include job grouping. Job grouping can be
helpful if you are checking multiple rooms at a site, or multiple jobs throughout the course of a work day.
The user can set the temperature and wood species for each individual job, and set the meter to read on a
particular material. Individual readings then may be stored for on screen recall or can be downloaded to a
PC.
Once the readings are downloaded, the user can save them in a spread sheet, assign name and address,
and add notes to each job. This enables the user to provide written documentation and proof of the
readings for each job. This way, the customer or insurance company can easily track the contractor’s work
to ensure proper drying took place.
Page 31
6.1.7
Thermal Imaging
Thermal imaging cameras detect radiation in the infrared range of the electromagnetic spectrum and
produce images of that radiation. The amount of radiation emitted by an object increases with
temperature; therefore, thermography allows one to see variations in temperature. When viewed through
a thermal imaging camera, the surface of wet objects is generally cooler than the surrounding materials
due to water evaporation from the surface of the wet objects. As a result, thermography is particularly
useful in building diagnostics where the building has been affected by water intrusion.
Thermal imaging cameras can help simplify restoration and remediation jobs. Advanced features help you
quickly scan large areas to assess what is potentially wet. An infrared camera helps you pinpoint water
intrusion, find moisture beneath the surface, and document dryness with accuracy and confidence. A
thermal imaging camera does not measure moisture it gives a visual representation of what is potentially
wet. Positive indications of moisture should be followed up with moisture readings.
6.2 Measuring Moisture in Building Materials
6.2.1
Quantitative Readings
Moisture readings can be based on quantitative or qualitative readings. Percentage Moisture Content
(%MC) or Quantitative readings are based on meters that express the value in percent of moisture in the
material expressed as a percentage of the materials oven dry weight. These reading are valuable when
compared to known equilibrium moisture content of the building materials being measured. Percentage
moisture content of building materials will vary according to the relative humidity.
6.2.2
Qualitative Readings
Wood Moisture Equivalency (WME) is a relative reading obtained from using a wood moisture meter on a
non wood building material. The reading of the amount of moisture on the meter does not represent the
actual percentage of water in the material. However a higher reading represents more moisture than a
lower reading. These readings are only valuable when compared to another moisture reading from the
same building material.
Some meters can be calibrated for specific non wood building materials such as concrete or gyprock.
Readings from these meters whilst more accurately representing the actual moisture percentage are still
considered to be relative readings and comparative reading or dry standard should be established.
6.2.3
Dry Standard
Dry standard is a sample reading taken from the same building material in an unaffected area of the
building. This sample relative reading is then used as the control reading or drying goal for that particular
building material. If the building has been totally saturated it is suggested using a similar construction
elsewhere to obtain a dry standard.
Page 32
6.2.4
Equilibrium Moisture Content (EMC)
EMC refers to the amount of moisture in a material when it has achieved equilibrium with the relative
humidity of the surrounding air. For the purposes of water damage restoration when the building materials
moisture content is at EMC the building material is considered to be dry.
6.2.5
Equilibrium Relative Humidity (ERH)
ERH Refers to the amount of moisture in the air expressed in relative humidity, when it has equalised with
the moisture in the surrounding materials. For the purposes of water damage restoration when the relative
humidity of the air surrounding a building material is at ERH the building the material is considered to be
dry.
ERH tests are particularly useful in providing quantitative results when determining the potential for
secondary damage or microbial activity caused by organic materials such as wood floors installed directly
over a concrete slab.
Page 33
7 The Drymatic System
7.1 Introduction
The Drymatic system is a revolutionary new way of drying buildings and it changes how traditional drying
methods operate. It also changes the way that the drying regime is monitored, as unlike most systems, the
Drymatic method is to get the air in the room as wet as possible, purge the air and start again. For interior
use only as a room drying system where flood damage has occurred or where drying to exacting standards
is required.
The Drymatic system can be used in conjunction with remote wall sensors to monitor room temperature
and humidity. Based on the sensed temperature and humidity the system is electronically controlled to
achieve the desired room drying level.
The system should only be used by qualified and trained personnel.
Drymatic System
Page 34
Drymatic System Conrol Panel
7.2 Drymatic Operating Modes
Page 35
7.2.1
Re-circulation Mode
•
Air from the room is heated and re-circulated; only the recirculation fan will be on in this mode. Air
will be drawn in through the “Re-circulate Air from Room” duct and warm air exhausted through
the “Heater Outlet”. The “Recirculation” light will be illuminated.
•
Once the room reaches a steady state temperature or when 2 hours have elapsed the unit will
switch to “Exhaust Mode”.
•
No wall sensor data is collected or data written to the Data Card in Re-Circulation Mode.
7.2.2
Exhaust Mode
•
The “Exhaust” light will be illuminated, the Exhaust fan will start (the recirculation fan and heater
will also be on). This will remove warm moist air from the room and vent it to the outside of the
building via the external ducting for a maximum of 8 hours .
•
The air that will be heated in order for it to pick up moisture from the room is drawn in from
outside the building.
•
Ensure that the Exhaust and Intake hoses are not close to each other outside the building, as moist
air will be drawn back into the room.
•
If the temperature in the room drops by 33% of the steady state value reached in Recirculation
Mode, the unit will switch back to Recirculation Mode, to increase the room temperature back to
the optimum level.
•
In order for the room to be considered in a “state of dryness”, the exhaust air %Relative Humidity
and wall sensor Specific Humidity must be less than or equal to the value set on the Room Setting
%RH dial.
•
When the room is in a “state of dryness” the system will remain in exhaust mode with the heater
‘off’ until the system is powered down.
•
The exhaust LED will flash and a “Room dry” SMS message will be sent.
Page 36
7.3 Installation Procedure
Connect ducting as per the diagrams below.
Air from outside or preconditioned air
from an unaffected area
Air to Outside
Heater Outlet Optional
Page 37
7.4 System Set-Up
7.4.1
•
7.4.2
Step One – Connect Power
Connect to a 230V single phase mains supply via the 3-pin mains plug provided.
Step Two – Insert Data Card (skip if not using)
•
Insert the Data Card. The logo should be facing down with the gold contact closest to the machine
into the slot on the right hand side of the control panel.
•
The card cannot be removed when the error light is on and code ‘202’ is on the display.
•
IMPORTANT: Do not remove or insert a card while the key switch is in the ‘Unlock’ or ‘Reset’
position.
•
To change the card whilst the machine is running you must ensure that the key switch is in the
‘Lock’ position and Error 202 is not displayed then remove the card. Wait 30 seconds and then
insert new card. Any old data on the card will be overwritten.
•
Once data is erased it cannot be recovered!
•
Data is written to the card once an hour, an empty card can store up to 100 days of data.
•
Only the wettest and driest wall sensor data is logged to the card.
Page 38
7.4.3
•
7.4.4
•
7.4.5
•
Step Three – Switch On
Switch the unit on via the red isolator switch.
Step Four – Error Code 0000
Upon power up the error light and code ‘0000’ will be shown.
Step Five – Reset Data Card (skip if not using)
If the Data Card needs to be wiped, go to RESET
Reset
•
If the key is turned to the RESET position:
•
The KWh and current operational settings will be erased.
•
After a 20 second countdown Info Code “202” will be displayed while the Data Card is being wiped.
This will take approximately 60 seconds. This feature is also available on the PC software.
•
After another 20 second countdown Info Code “101” is displayed. This indicates that a wall sensor
deactivation signal is being transmitted. Any wall sensors within line of sight of the transmitter will
be deactivated. It can take up to 30 seconds to deactivate a sensor, several wall sensors can be
deactivated at the same time. To exit this mode, turn the key to another position.
7.4.6
Step Six – Unlock and set dials
•
At the key switch on the Control panel, turn the key to the ‘Unlock’ position.
•
This allows the room drying conditions to be set. You have 30 seconds to adjust the dials. Once the
error light goes out, the dials are set.
7.4.7
Step Seven – Starting up
•
After a 20 second countdown (Shown on display), the IR Wall Sensors can be activated with their
unique ID’s.
•
If wall sensors are not required, turn the key to the “Lock” position.
•
Drymatic will start in recirculation mode. The key can be removed; repositioning dials will not effect
the original setting once the key has been removed.
Page 39
7.5 Sensor Activation
1. After the dials have been set in the “Unlock” key position, there will be a 20 second countdown on
the display which is then followed by the wall sensor activation mode.
2. To activate the sensors with their unique ID’s:
•
Switch sensor on.
•
After the countdown reaches 1, the number 2 will be displayed. (This will be the ID number of
the first sensor).
•
Hold a sensor with the clear plastic window facing the ‘Transmitter lens’ on the side of the
Drymatic unit. It must be more than 300mm (1ft) away from the ‘Transmitter lens’.
Once the ID has been given to the sensor, the display will show ‘0000’. The sensor must now be
moved out of line of sight from the transmitter before the next number is displayed. The
sensor’s green light will flash once every 60 seconds to show that it is active.
• The next ID will be displayed, repeat step 2 until the required numbers of sensors have been
activated.
3. To exit Sensor Activation Mode, turn the key to the “Lock” position.
•
Page 40
4. Ensure that all other sensors are out of sight from the transmitter while activation is being
performed. If two sensors are activated with the same ID, the data from these wall sensors will not
be relayed back to the Drymatic.
5. Up to 24 wall sensors can be activated. Take note of where each sensor is placed in the room, as
the data retrieved from the Data Card will only make reference to the sensors ID number.
Wall Sensor Installation:
1.
2.
3.
4.
5.
Drill a 12.5mm hole in the wall. (Ensure safe drilling practices are observed).
Remove knock outs from wall plug.
Insert yellow plastic wall plug fully into wall.
Gently push activated wall sensor into plug. It will not insert completely.
Do not block the sensor hole at the end of the probe.
Wall Sensor positioning
IMPORTANT: One Wall sensor must be positioned directly in line of sight with the transmitter lens.
The wall sensors communicate with the Drymatic unit via an infra-red link. For best results, each sensor
should be positioned so that the ‘Transmitter lens’ is within range – approximately 9 metres.
Ideally, each sensor needs to be ‘visible’ to the ‘Transmitter lens’, i.e., not obscured or obstructed by a solid
object either in front of the ‘Transmitter lens’ or in front of the sensor itself.
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Each sensor transmits a packet of data not only to the Drymatic, but to all other sensors. Therefore any
data that fails to reach the Drymatic directly but has been captured by a neighbouring sensor will be retransmitted by its neighbour.
The sensors can also be inserted into ceilings thereby giving extra coverage for room drying. Each sensor
has a green LED which flashes to indicate that it is operational. The LED will flash five times during data
transmission.
7.6 SMS Text Messaging
The Drymatic system once configured and in operation, has the ability to send status information via SMS
(Text) messages allowing the system to be left onsite, in operation until drying is complete.
Once the system has reached its pre-set levels, the system will send an SMS text message to the preprogrammed mobile phone supplied to alert the user as to the operational status of the Drymatic.
IMPORTANT: Due to some mobile phone network requirements, upon power down the Drymatic will make
a voice call to the phone; if this call is not answered (hang up after a few seconds) every few weeks the
machine could become disconnected from the network. Disconnection can only be corrected by a service
engineer.
SMS messages used are as follows:
•
•
•
•
•
•
•
•
Blockage
Maximum Dial Exceeded
Room dry
Filter nearing saturation
General error
Wall Sensor Network failure
Data Card 24hrs remain
Power failure
Blockage: System alarm to indicate a duct blockage has occurred. The effect of this is that the heater is
turned-off to prevent overheat and damage occurring. The operator will need a site visit to check all
ducting is unblocked and free of restrictions before restarting the system.
Maximum Dial Exceeded: System alarm to indicate that either the humidity or the temperature have
reached the values set on the “Maximum Room %RH” and the “Maximum Room Temperature” dials.
Room dry: System alarm to indicate that the room has reached the pre-set drying criteria. The system will
automatically enter Exhaust Mode with the heater turned off but fan still running. The Exhaust LED will
flash to signify that the room is dry.
Filter nearing saturation: System alarm to indicate when the air intake filter is nearly blocked
(approximately 75% blocked). The operator will need a site visit to change or clear the filter medium.
General error: System alarm to indicate that there is a fault that requires a service engineer.
The errors covered are:
•
No heat being produced.
•
KWh not being logged.
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Wall Sensor Network failure: System alarm is to indicate that no wall sensor data is being received by the
Drymatic unit. If no sensors have been activated and the Data Card also holds no record of this, no message
is sent.
Data Card 24hrs remain: System alarm is to indicate that the available memory remaining on the Data Card
has reduced to 24 hours logging. The operator will need a site visit to change Data Cards over and provides
the operator with advance warning to schedule time for the card changeover.
Power failure: System alarm to indicate that mains power to the unit has been removed or interrupted and
the system is inactive. The operator will need a site visit to check the system supply and system setting.
Note, that even though the power supply to the system has been lost, the unit is fitted with battery backup to enable text messaging in the event of a power failure.
Data stored on the Data Card will not be lost, but upon power-up the system will need to be restarted, the
KWh will return to zero.
WARNING: The old data will be overwritten if the card is left in and the machine is initiated again.
The Wall sensors will not need to be reactivated provided the power failure happened after more than 3
hours of operation.
Page 43
8 Appendix
Page 44
8.1 Psychrometric Chart
Page 45

Introduction to Structural Drying Manual

Transcription

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