What to Look For When Buying a Residential Heating System
Today’s high-efficiency air conditioners use about 30% to 50% less energy than those just a couple short decades ago. Even if your air conditioner is only 10 years old, you may be able to save 20% to 40% by replacing your current air conditioner with a recent, more efficient model.
But the efficiency of the model alone is not sufficient. You must evaluate the efficiency of the unit within the environment you wish to cool.
Purchase the Right Sized Air Conditioner
Air conditioners are rated by the number of British Thermal Units (BTUs) of heat they can remove per hour. Another common rating term for air conditioning size is the “ton,” which is equal to 12,000 BTUs per hour. The efficiency, performance, durability, and initial cost of an air conditioner are functions of matching its size to the following factors:
- The size of your home and the number of windows it has,
- The amount of shade that falls on your home’s windows, walls, and roof,
- How much insulation is in the ceiling and walls of your home,
- The amount of air that leaks into your home from the outside, and
- How much heat is produced by the occupants and other appliances in your home.
Consumer Hint: Two groups, the Air Conditioning Contractors of America (ACCA) and the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) publish calculation procedures for sizing central air conditioners. Reputable air conditioning contractors will use one of these procedures, often performed with the aid of a computer, to size your new central air conditioner.
Remember that a large air conditioner will not necessarily provide the best cooling. In fact, installing an air conditioner that is too big for your needs will always be less efficient and may even be less effective. Here are some of the negative consequences:
- The larger the air conditioner you buy, the more it will cost up front.
- A larger-than-necessary air conditioner switches on and off more frequently, which reduces its efficiency.
- This frequent cycling makes indoor temperatures fluctuate and creates a less comfortable environment.
- Frequent cycling also minimizes moisture removal that is essential for comfort in humid climates.
- Constant on/off switching wears out the compressor and electrical parts more rapidly increasing repair and maintenance costs and almost always necessitates premature replacement
- A larger air conditioner uses more electricity and creates added demands on electrical generation and delivery systems.
Air Conditioner Efficiency
Every air conditioner has an energy-efficiency rating of that identifies how many BTUs per hour are removed from the space for each watt of electricity it consumes. For room air conditioners, we call this the Energy Efficiency Ratio (EER). For central air conditioners, it is the Seasonal Energy Efficiency Ratio (SEER). You’ll find these ratings on the Energy Guide Label that is visibly attached to all new air conditioners. Many air conditioner manufacturers participate in the EnergyStar® labeling program. This insignia means that the product complies with high efficiency standards and generally reflects high EER and SEER ratings.
Usually, new air conditioners with higher EERs or SEERs are more expensive. But don’t let that put you off. The higher priced unit will pay you back many times over during the life of the system in reduced energy costs.
We strongly recommend that you purchase the most efficient air conditioner you can afford, especially since you are living in an area where demand and power rates are high.
Consumer Hint: Because of their interest in conserving stretched energy resources, utility companies sometimes offer cash rebates and other incentives for consumers to invest in higher efficiency systems. Allow us to check with your power company to see if any such opportunities are available.
Room Air Conditioners (EER) – A room air conditioner usually “ices” between 5,500 and 14,000 BTU per hour. Room air conditioners built since January 1 of 1990 are required by the National Appliance Standards to have an Energy Efficiency Ratio (EER) equal to or greater than 8.0. In the Mid-Hudson climate, select a room air conditioner with an EER of at least 9.0.
According to the Association of Home Appliance Manufacturers, the average EER of room air conditioners rose 47% from 1972 to 1991. If you own a room air conditioner from the 1970s with an EER of 5 and you replace it with a modern one that has an EER of 10, your air conditioning energy costs will be reduced by 50%.
Central Air Conditioners (SEER) – The minimum standards for central air conditioners require a Seasonal Energy Efficiency Ratio (SEER) of 9.7 and 10.0 for single-package and split-systems respectively. However, you do not need to settle for the minimum standard. Central air conditioning units offer SEERs up to almost 17. Choose the highest rating you can afford.
Consumer Hint: Central air conditioning units made before 1979 had SEERs ranging from 4.5 to 8.0. You can cut you’re your air conditioning costs in half if you replace your 1970s central air conditioner that has a SEER of 6 with a new unit having a SEER of 12.
The Noise Factor
Some Central AC units can produce some noise. This is generally not a problem for a unit located outside the home, but is a factor you should consider in making your purchase if the unit will be placed in proximity to bedrooms or other high-traffic living areas, or if it is in close proximity to neighbors. Most late model units have sound ratings that are measured in decibels.
Installation and Location of Air Conditioners
Once correctly installed, your air conditioner should perform efficiently for years with only minor routine maintenance. Too often, however, air conditioners are not installed correctly. This could result in even a late-model, high efficiency system performing almost as poorly as an older one. Again, this underscores the importance of choosing a reputable contractor you know you can trust.
Here are a few important things to look for in the installation of your new central air system.
- Allow sufficient indoor space for the installation, maintenance, and repair of the new system.
- Install an access door in the furnace or duct to clean the evaporator coil.
- Use a duct-sizing methodology such as the Air Conditioning Contractors of America (ACCA) Manual D standard.
- Make sure there are enough supply registers to distribute cool air throughout the space, and enough return air registers to carry warm house air back to the air conditioner.
- Wherever possible, install ductwork within the air conditioned space, not in the attic. Where that is not possible, make sure the ductwork is well-insulated.
- Seal all ducts with duct mastic and heavily insulate attic ducts.
- Locate the condensing unit where its noise will not keep you or your neighbors awake at night.
- If possible, place the condensing unit in a shady spot, which can reduce your air conditioning costs by up to 2% or more.
- Verify that the newly installed air conditioner has the exact refrigerant charge and airflow rate specified by the manufacturer.
- Locate the thermostat away from heat sources, such as windows, or supply registers.
- When replacing an older or failed split system, be certain to replace the evaporator coil with a new one that exactly matches the condenser coil in the new condensing unit. (If the existing evaporator coil is left in place, not only is it likely that the air conditioner’s efficiency will not improve, but the old coil could actually cause the new compressor to fail prematurely.)
When installing a new room air conditioner, consider these guidelines:
- Whenever possible, position the air conditioner in a window or wall area near the center of the room and on the side of the house with the most shade.
- Use foam weather-stripping material to fit the room air conditioner tightly into its opening and seal any gaps. This will diminish air leakage and increase efficiency.
Speak to one of our Customer Service Representatives by calling 866-491-2768 today.