The heating and cooling systems
of your home are also known as its HVAC equipment. This acronym stands for
Heating, Ventilation & Air Conditioning. The HVAC equipment is responsible
for the temperature, humidity & quality of the indoor environment and
comfort for the habitants.
There are many different types of
heating, ventilating & cooling equipment. The type of equipment used in any
particular area has to with its climate. The length & coldness of winter
and the length & hotness of summer are the main factors in determining what
is needed. The humidity levels also play an important role on what equipment
would be required.
HEATING SYSTEMS
Heating your home obviously is a
process of adding heat to the indoor environment therefore increasing the
temperature. The typical winter time thermostat temperature setting is 66F to
70F with the average being around 68F. This is a reasonable temp for comfort
and efficiency. Below are the most common heating systems installed in new
homes today.
Forced Air - Most common
type of heating and cooling systems used. A blower circulates air across a heat
exchanger to heat the home. A/C systems can added to these systems.
Heat Pump - There are
several types of heat pumps, however most common is the air-source heat pump.
Heat pumps provide the heating and cooling for your home.
Hydronic - Water is heated
by a boiler and circulated through radiators located in the home.
Radiant - Water is heated by
a boiler and circulated through tubing located in floors, walls or ceilings to
warm those surfaces which in turns heats the space by radiation.
Geothermal - A heat pump
that uses the ground or water for its heat source. It serves your heating and
cooling needs in one system.
Electric - Heat is supplied
through electric or resistance heaters when electricity is passed through the
device.
COOLING SYSTEMS
The cooling of your home, also
known as air conditioning, is the removal of heat to cool and dehumidify the
indoor air. The typical summer time thermostat setting is 74F to 80F with the
average being around 78F. This average temperature is reasonable for comfort
and efficiency. Below are the most common A/C systems installed in new homes
today.
Forced Air - Most common
type of heating and outdoor cooling
systems installed. A compressor circulates a refrigerant between two coils
(one indoors & one outdoors), then a blower blows through the indoor coil
which removes the heat from the home and then it is circulated to the exterior
to dissipate the heat that was absorbed to the outdoor air. It uses a system of
ductwork to distribute the conditioned air throughout the home.
Ductless Split System - A
mini-split air conditioning system. Similar to the traditional split system,
however each room has a air handler located it for individual control and
therefore no need for ductwork.
VENTILATION
The purpose of ventilation in a
home is to help control the indoor air quality & humidity levels. It is
best to control this ventilation through the heating and cooling systems of the
home.
Kitchens and bathrooms have
ventilation systems for removal of odors and moisture. If these are ducted
through unconditioned areas (ex: attic, crawlspace), they should be insulated
to prevent condensation from forming.
Clothes dryers are another form
of ventilation where the moisture is vented to the exterior. This ducting
should be made of metal pipe for proper fire protection and its joints are to
be only taped together (high quality aluminum tape is best) as screws will
collect lint & eventually clog the duct. Clothes dryers should NEVER be
vented to the interior (some stores sell this type of lint collector for this
purpose) as this will increase the indoor humidity levels tremendously and will
contribute to mold growth & poor indoor air quality.
Today's homes are being built
much tighter therefore allowing less infiltration of outdoor electric. The air exchange
rate (outdoor air that leaks into the home) of newer homes is much lower than
older homes, therefore the indoor air can become stagnant and unhealthy if
nothing is done to increase this air exchange rate. Most home heating and
cooling units, including forced air heating systems, do NOT mechanically bring
fresh air into the house.
One way of doing this is with a
heat recovery ventilator. This device brings in outdoor air through a type of
exchanger where the indoor also passes through it, therefore transferring the
heat from the indoor air into the outdoor air that is being brought into the
home. You can also installed a duct on your HVAC return plenum directly from
the outdoors so that any time your home is under negative pressure, it draws the
air through this duct instead of through the cracks in your home.