Applications
Air
Distribution System Fan Recycling Control
Ventilation
Systems
Outside
Air Duct into the Central System Air Handler Return Plenum
Ventilation
systems that provide ventilation air through a duct that extends from
outdoors to the return plenum of a central air handler only supply ventilation
air when the fan is operating. Rather than operating the central system
fan continuously, which can waste energy and can also lead to moisture
related problems in humid climates, the recycling control can be set
to periodically distribute ventilation air during stagnant periods when
there is no call to circulate air for purposes of heating or cooling.
An
economical and effective ventilation system, using the FanCycler,
would be a 6" to an 8" diameter insulated duct (depending
on the house size) from outdoors to the return of the central air distribution
fan (see diagram below). This outside air should be filtered before
it enters the central return duct, and a balancing damper is advisable
to give additional field control of the delivered outside air volume.
The FanCycler control functions to guarantee
that fresh air will be periodically distributed throughout the house
when there is no call for heating or cooling, but it is energy efficient
since it only does this if the central fan has not operated for a preset
time. A very important added benefit, is that builder call-backs due
to thermal comfort or air quality problems may be greatly reduced because
the FanCycler will even-out temperature, humidity and stuffiness
conditions between rooms and the main body.
Single-Point
Exhaust or Single-Point Supply Ventilation System
For
single-point exhaust or single-point supply ventilation systems, the
supply or exhaust point is usually located in the main body of the house.
In this case, closed rooms, such as bedrooms, will not receive adequate
ventilation air unless the central system fan operates to mix air between
the main body and the closed rooms. Rather than operating the central
system fan continuously, which can waste energy and can also lead to
moisture related problems in humid climates, the FanCycler control
can be set to periodically distribute ventilation air throughout the
house during stagnant periods when there is no call to circulate air
for purposes of heating or cooling.
Enhanced
Temperature Control Systems
Thermostats
are typically located in a central area and are expected to serve an
entire zone that usually includes closed rooms, and often, more than
one floor level. Temperature conditions can vary widely between the
thermostat location and extremities of the space the thermostat serves.
A practical solution to this problem could be to utilize the central
system fan to average the overall space conditions by mixing. Rather
than operating the central system fan continuously, which can waste
energy and can also lead to moisture related problems in humid climates,
the FanCycler control can be set to periodically mix house air
during stagnant periods when there is no call by the centrally located
thermostat to circulate air for purposes of heating or cooling.
Enhanced
Humidity Control Systems
In
humid climates, dehumidification, separate from the central cooling
system, may be used to maintain comfort in seasons where there may be
long periods of high humidity while indoor temperatures are within personal
comfort ranges. In order to reduce system cost, it may be practical
to locate a single dehumidifier in the main body of the house. In this
case, closed rooms, such as bedrooms, will not receive the dehumidification
benefit unless the central system fan operates to mix air between the
main body and the closed rooms. Rather than operating the central system
fan continuously, which can waste energy and can also lead to moisture
related problems in humid climates, the FanCycler control can
be set to periodically distribute dehumidified air throughout the house
during stagnant periods when there is no call to circulate air for purposes
of heating or cooling.
For
either dehumidifiers that are connected to the central air distribution
system ducts, or for dehumidifiers that are stand-alone, humidistats
are usually located in a central area and are expected to serve an entire
zone that usually includes closed rooms, and often, more than one floor
level. Humidity conditions can vary widely between the humidistat location
and extremities of the space the humidistat serves. A practical solution
to this problem could be to utilize the central system fan to average
the overall space conditions by mixing. Rather than operating the central
system fan continuously, which can waste energy and can also lead to
moisture related problems in humid climates, the FanCycler control
can be set to periodically mix house air during stagnant periods when
there is no call to circulate air for purposes of heating or cooling.
Air
Cleaning Systems
Air
Cleaner or Special Filtration Equipment at the Central Air Handler Return
Air
cleaning or special filtration systems that locate the cleaning or filtration
media at the return side of the central system air handler will perform
their intended function only when the central system fan is operating.
Rather than operating the central system fan continuously, which can
waste energy and can also lead to moisture related problems in humid
climates, the FanCycler control can be set to periodically distribute
cleaned or filtered air throughout the house during stagnant periods
when there is no call to circulate air for purposes of heating or cooling.
Single-Point
Air Cleaner or Special Filtration Equipment
In
order to reduce system cost, it may be practical to locate a single
air cleaner or special air filtering device in the main body of the
house. In this case, closed rooms will not receive the air cleaning
or filtration benefit unless the central system fan operates to mix
air between the main body and the closed rooms. Rather than operating
the central system fan continuously, which can waste energy and can
also lead to moisture related problems in humid climates, the
FanCycler
control can be set to periodically distribute cleaned or filtered air
throughout the house during stagnant periods when there is no call to
circulate air for purposes of heating or cooling.
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