- Forced hot air heat
is one of the most common types of heating used.
The two main types used are gas fired and oil fired. These furnaces
have an average lifespan of 20 – 30 years. The best thing you can do to
maintain healthy household air during the heating season is to use a high
efficient filter and to change it regularly (every 2 – 3 months). Most
people use the blue fiberglass filters (7 – 8 % efficient). These filters stop
only the largest of airborne particles and hair. They let everything else pass
through to recirculate around your house making them essentially useless. The
best type of filter to use is the highest efficiency disposable filter you can
find. We recommend the 3M Filtrete disposable furnace filter. The top
version of this filter is 90 – 95% efficient for dust and allergens and does a
good job of keeping your house air clean. Filters must be the proper size. A
filter that is smaller than the opening it is designed for allows dust
particles to recirculate. Filters have a directional arrow on the side to
indicate which direction the filter must be installed.
- It’s a good idea to set up some type of service contract with the
gas company, oil supplier, or an HVAC professional to service your furnace
regularly. Oil fired furnaces and boilers require yearly service to keep
them working properly. An improperly maintained oil fired furnace or
boiler can experience problems with oily soot buildup on the burners and
result in incomplete combustion or possible carbon monoxide buildup in the
house. Another possible result of an improperly maintained oil fired system is
a puff back. A puff back occurs when there is a buildup of oil soot in
the burner chamber from lack of maintenance. During the next call for heat,
the system fires and blows the oily soot buildup out of the furnace and into
your house.
Boilers / Radiator & Baseboard Hot Water Heating
- Radiator or baseboard hot water heating
coupled with a hot water
boiler is another common type of heat source. The concept for this heating is
actually quite simple. Think of a hot water boiler (either gas or oil
fired) as a big pot of water. When the burner compartment in the boiler turns
on, it heats the water and moves it through the piping system and to the
radiators. The radiators absorb the heat from the water in the pipes and heat
the rooms in your house. There is no air filter with these types of systems.
These systems should also be maintained with some type of service contract.
- There are a few things you can monitor on your boiler to be sure it is
operating properly. One is the pressure gauge. Boilers have pressure gauges
to measure the operating pressure of the system. A house with two floors
should have a standing pressure in the boiler of 12 at least psi (pounds per
square inch). Standing pressure refers to the pressure in the boiler
when the system is idle or not running. A house with three floors should have
a standing pressure of 17 psi. If the standing pressure is too low, it could
mean the pressure gauge is defective or the system needs to have water added.
When the system is operating and the boiler is firing, the pressure gauge
should rise slightly, maybe one pound or so. If the pressure increases too
much, it may mean that the expansion tank for the boiler is waterlogged and
needs to be partially drained. If the pressure drops, it means there is a leak
somewhere in the system and service is required.
- If you notice uneven heating on the surface of the radiators
(hot and cold spots), it may mean there is not enough water in the system or
there is air in the pipes. Individual radiators can be "bled" to
release air in the pipes through a valve stem on each radiator. The valve is
opened to release air and closed once water comes out. Bleeding the radiators
should be done at the beginning of each heating season. Start at the radiators
on the lowest floor of the house and work up to the highest floor.
- If leaks are noticed anywhere in the system (radiators, piping system, or
boiler) contact an HVAC professional to service the boiler.
- Boilers also have what is known as a temperature & pressure relief
valve (TPR). Its purpose is to discharge water from the boiler if the
internal water temperature of the boiler exceeds 210 degrees F or 30 PSI. If
water temperatures or pressures were allowed to exceed these points, the
boiler could become damaged or worse, the boiler could explode. The TPR valve
should have a directional pipe installed that points towards the floor and
ends about six (6) inches above the floor. This helps prevent anybody standing
nearby from getting burned with scalding water if the TPR valve were to open.
This exhaust pipe should never be capped or plugged shut.
Heat Pumps
- Heat pumps
are either split or single package systems that both heat
and cool a house. In heat mode, the compressor, which sits outside the house,
circulates liquid refrigerant through the piping system and absorbs heat from
the outside air. Liquid refrigerant boils at extremely low temperatures (-40
degrees F) and therefore can absorb heat from air that seems cold. The heated
refrigerant then runs to a coil inside the indoor air handler and has air
blown over it from the air handler fan. The heat picked up from the heated
refrigerant blows through the duct work and heats the house. Heat pumps are
very efficient systems but draw some complaints from people not used to them.
Standard gas and oil fired furnaces produce output air of 130 degrees. Heat
pumps produce output air of approximately 90 degrees which feels cool to the
skin but is high enough to raise the temperature in your house. When outdoor
weather conditions get extremely cold, the heat pump loses efficiency and
produces cooler air. It will still hat your house but it will do it more
slowly. Heat pumps have an emergency backup mode to provide heat in
case the heat pump system fails. The emergency heat is typically electric and
is located within the supply plenum of the air handler and is very expensive
to run full time. Some systems may have oil or gas heat installed and used as
the emergency backup heat source. Do not run a heat pump in heat mode when
the outside temperature is above 80 degrees F. Doing so can damage the unit.
Likewise, do not run a heat pump in cooling mode when the outside temperature
is below 60 degrees F. Doing so can damage the unit.
Summer/Winter Hook-Up Systems
- Summer/winter hook-up systems employ a gas or oil fired boiler to
heat hot water for radiator or baseboard heating. They also provide the hot
water for your house and eliminate the need for water heater tank. Since this
type of system is in use year round, even when there is no need for heat, it
is called a summer/winter hookup. The hot water supplied by the boiler for
personal use is the same temperature as the water used to provide heat.
Therefore, the output temperature of hot water at sinks, faucets, and bathtubs
in the house can exceed 150 degrees. This is a very dangerous temperature that
can result in instant scalding and burning of exposed skin. To prevent
accidental scalds, a tempering or mixing valve should be attached to the main
hot water supply line. The tempering valve mixes cooler water with the hot
water from the boiler to reduce the temperature of personal use hot water to a
safe level.
- Summer/winter hook-up systems also have a temperature & pressure relief
valve (TPR). Its purpose is to discharge water from the boiler if the
internal water temperature of the boiler exceeds 210 degrees F or 30 PSI. If
water temperatures or pressures were allowed to exceed these points, the
boiler could become damaged or worse, the boiler could explode. The TPR valve
should have a directional pipe installed that points towards the floor and
ends about six (6) inches above the floor. This helps prevent anybody standing
nearby from getting burned with scalding water if the TPR valve were to open.
This exhaust pipe should never be capped or plugged shut.
Electric Heat
- Either an electric furnace or electric baseboards generate electric heat
.
Both systems are considered to be efficient because the electricity you pay
for with them is converted 100% into heat and none of the heat is lost up a
chimney. However, electric heat is expensive to run as a primary heat source
and can result in high electric bills. Electric furnaces use a coil
with electric toaster-type elements that heat up. Hot air is then blown over
them to be circulated around the house. Electric baseboard heaters use
an electric element that heats up and delivers heat to the rooms by means of
natural convection. No gas or oil is needed for either of these systems as
electricity is the heat source. Electric baseboard heaters must be installed
properly in order to provide adequate heat. These heaters provide heat through
convection (cold air falls and warm air rises) and therefore, need to be
installed with the opening at the bottom of the baseboard unobstructed.
Combustible materials, papers, curtains, and furniture should be placed an
adequate distance away from electric baseboard heaters to prevent a fire
hazard. Wall-to-wall pile carpeting with padding underneath can block the
opening at the bottom of baseboards and prevent the proper flow of air around
the baseboard heating fins. This applies to hot water hear baseboards as well.
Duct Work / Pipes & Circulators
- Duct work is a system of air vents that are piped throughout the
house to deliver heated air to different rooms in a house with a forced hot
air furnace. Some duct systems have dampers built into the ducts to allow you
to balance the system and reduce the amount of heat flowing into a certain
room. It is a good idea for people with allergies or sensitive respiratory
systems to have their duct work professionally cleaned and vacuumed. Ducts
accumulate dust concentrations over years of use and if a central A/C system
is in place, mold spores could be present from the moisture.
- Heating systems that use boilers to provide hot water heating use pipes
and a circulator pump instead of duct work. The circulator pump moves the
heated water through the piping system and the pipes carry the heated water to
the radiators or baseboards.
Thermostats
- The heating thermostat is typically located in the main living area
of the house and should be visibly mounted on a wall. The thermostat should
not be located in an area that is particularly drafty, hot, or in direct
contact with sunlight coming through a window. Installations in these areas
can result in an overheated or underheated house due to false readings of the
actual temperature of the house. Some houses that have more than one heating
zone have more than one thermostat. A good idea for any household is to
replace a single mode thermostat with a programmable setback thermostat.
These thermostats allow you to program the heat cycles to fit your lifestyle.
You can program it to automatically drop down to 62 at bedtime, rise to 68
when you get up for work, drop to 62 when you leave for work, and rise to 68
when you return home. Setback thermostats used in this manner can save 10 –
15% or more on your annual heating bill. Heat pump thermostats are
different from thermostats for boilers or forced air furnaces. They are
designed to only allow temperature increases of 1 - 2 degrees at a time in
heat pump mode. Moving the thermostat setting for a heat pump any higher than
this at one time will trigger the emergency heat mode to activate. Emergency
heat mode on the thermostat is indicated by a red light. To prevent this from
happening and paying for expensive electric heat, move the thermostat up only
one (1) degree at a time or remove the thermostat cover to expose the mercury
bubbles. The heat lever will have two (2) mercury bubbles. The bottom bubble
controls the heat pump and the top bubble controls the emergency backup. Move
the heat lever just enough to activate the heat pump without activating the
backup. Heat pumps are at their most efficient when their thermostat is set at
your desired temperature and left alone. Special setback staging
thermostats are available for heat pumps. They are programmable and
increase your house temperature 1 – 2 degrees at a time before cycling up and
raising the temperature again. This allows for large temperature increases
without activating the emergency backup heat.