Heating System
STRATEGY: If your heating bills are high, your first thought might be to put in a new high efficiency furnace. But your first step should be to tighten up the house and adequately insulate it. Then consider furnace replacement. If you install the furnace and then make other energy improvements, the furnace will be oversized and might not operate properly or at peak efficiency. By making other improvements first, you may be able to reduce your furnace size. After making improvements, the 90% + efficiency furnace may no longer be your best investment because your heating demand is much lower. The lower your heating demand, the more the 75-85% efficient furnace tends to be a better investment. When replacing a furnace in a tight house, it is recommended that you install one with an induced draft fan or sealed combustion using only outside air.
MYTHS ABOUT HEATING:
MYTH: If you turn down your thermostat at night or when you are gone, you will use more energy to warm up the house again than what you saved.
FACT: You always save by turning down your thermostat no matter how long you will be gone. The one exception is an electric heat pump. When you turn it up in the morning, the electric back-up elements kick on to bring the house up to temperature faster. You can purchase a special setback thermostat that compensates for this and will provide savings.
MYTH: You should leave your pilot light burning during the summer to keep moisture from accumulating in your heat exchanger and rusting it out.
FACT: When gas burns, it gives off a considerable amount of water vapor. Leaving the pilot burning can actually cause the heat exchanger to rust more.
MYTH: You can warm up the house faster if you turn the thermostat up to 75-80 degrees initially.
FACT: The house warms up at the same rate no matter what temperature you set the thermostat at. Setting it higher can cause the furnace to overshoot the desired temperature, wasting energy.
MYTH: Installing a ceiling fan on an eight foot ceiling will keep warm air from accumulating near the ceiling and save considerable energy.
FACT: If you have forced-air furnace and/or a tight well-insulated house, there will be little if any difference in air temperature from the floor to ceiling. Running a ceiling fan creates a draft that could cause you to turn up your thermostat to feel comfortable. The only exception might be a vaulted ceiling.
HEATING TIPS:
- Use bath and kitchen vents sparingly when moisture and odors are not a problem.
- Lock your windows so they will seal tighter.
- Try to use doors that are protected from the wind.
- Be sure thermostat is located away from heat sources and cold drafts.
- Close drapes at night and on cloudy days.
OPERATIONAL TIPS:
- Set the thermostat at 68°F when occupied and 60°F at night or when unoccupied. If you are going to be gone for a few days turn it down as low as it will go.
- Close registers and doors to unused rooms.
- Don't block registers with furniture.
- Set the fan limit switch to come on at 100°F and off at 90°F
- Change the filter once every month or two.
- Have the furnace serviced (tuned) every 2-5 years.
- Lower boiler temperature in the spring and fall.
IMPROVING YOUR EXISTING FURNACE:
- Insulate pipes and ducts in unheated areas.
- Install an auto setback thermostat if you have trouble remembering to turn down your thermostat or want the house to be warm when you get up in the morning and when you return from work. (If you turn it down manually now, you won't save energy, but you will add convenience.)
- Install a vent damper. (If your water heater uses the same chimney for venting, you need to install one on it also.) Install a modulating aquastat on a boiler to adjust its temperature according to outdoor temperature.
- Tape all the joints in the ductwork.*
- Install an electronic ignition.*
- Install a heat reclaimer.*
- Install an induced draft attachment if there is a potential for flue gases to come back down the chimney.*
- Install outside air for combustion if your house is extremely tight.*
INSTALLING A NEW FURNACE:
- Install a new medium-to-high efficiency furnace. The efficiency is measured in AFUE (Annual Fuel Utilization Efficiency). Replacement should be considered only after the house has been tightened up and fully insulated.
*The items marked with an asterisk (*) are, for the most part, only marginally cost effective and may be done for reasons other than energy savings.
