Heating and cooling: 10 answers to frequently asked questions
Here are some common questions about heating and cooling:
1.What do efficiency rating numbers mean?
The U.S. government requires an efficiency rating of all air conditioning and heating equipment, and for most household appliances. The rating reflects the percentage of energy used efficiently, with a higher rating indicating higher efficiency.
2. What is SEER?
There are special names for the efficiency ratings of various types of equipment. Air conditioning equipment is rated by the Seasonal Energy Efficiency Rating, or SEER. The higher the SEER rating, the more efficient the equipment is. New equipment manufactured today by the manufacturers must meet at least a 13.0 SEER rating, with some manufacturers producing equipment as high as 21.0 SEER.
3. What does HSPF stand for?
Air conditioning systems, with a heat pump function, are rated by the heating seasonal performance factor. The higher the HSPF rating is, the more efficient the unit. HSPF is a ratio of BTU (British thermal units) heat output over the heating season to watt-hours of electricity used.
4. What does AFUE stand for?
Gas furnaces are rated according to their annual fuel utilization efficiency, or AFUE. The higher the AFUE rating is, the more efficient the unit. Natural draft furnaces or boilers typically have an efficiency rating of about 80 percent. Manufacturers, like Lennox, have developed more efficient furnaces to operate at up to a 98-percent efficiency rating; meaning 98 percent of the energy costs you are putting into your furnace are being used to heat your home, unlike natural draft furnaces that only use 80 percent of your energy costs. Boilers like the Weil McLain Ultra also provide high efficiency operation, topping 95 percent AFUE.
5. Should outdoor units be covered in winter?
It is not recommended. Air conditioners can be accidentally turned on by someone in your home without them knowing that the outdoor unit has been covered, whereby creating potential damage to your condenser and its internal components. The outdoor condenser is built to withstand the environment and should not be covered.
6. Should a thermostat be set to “auto” or “on”?
Preferably auto. That way, the fan operates only when the temperature requires it. This is the most used and the most efficient setting. However, there are advantages to using the “on” setting on your thermostat. Air is constantly filtered through the unit’s air filter, and the constantly circulating air results in more even temperature throughout the house. Many newer furnaces come equipped with fan motors that provide this function.
7. Can shrubs or flowers be planted around an outdoor condensing unit?
Yes. However, we recommend that plants be no closer than 18 inches to the unit. This allows for plenty of room for air circulation in and out of the unit. Without this room for air circulation, the unit could overheat, resulting in a premature need for service. Be careful to trim any plants or shrubbery to always allow for the spacing requirement.
8. If an outdoor unit needs replacing, should the indoor unit be replaced too?
It is recommended that both the indoor and outdoor equipment are replaced together, especially with the new EPA requirements to phase out R-22 refrigerant by 2020. Currently, there are other options to replace just one of the components without the other, with the price of inefficiency and high energy costs. That, however, is subject to change with the upgrades in building codes and National Energy Codes being enforced gradually, state by state. The efficincy rating on a condenser is based on the entire system being replaced.
9. How do I know what size unit our house needs?
A licensed and insured heating and air conditioning specialist should be consulted if you are considering replacement of your old equipment or the addition of new equipment. Many factors are taken into consideration before making an educated recommendation for properly sized equipment for your home. Factors like the square footage of your house, the climate, the number and type of windows installed, insulation, and even the number of people living in the house are all part of the proper calculation of the air conditioning system needed for your complete comfort.
10. What is the difference between a split system and a package unit?
A split system uses indoor (air handler/coil or furnace/coil) and outdoor (condenser) components to provide a complete home comfort system. A package unit contains all the required components (indoor and outdoor) within itself. A package unit is typically used in commercial applications or in condominiums and apartments.