Choosing the Correct Air Conditioning System in the OC

Air Conditioner Terminology

Choosing the best air conditioner for your home is easy once you have the right information. Before we dive into the shopping process it is important you speak the language so you can get the gist of things. That is why we have assembled this quick glossary of terms.

BTU

The British Thermal Unit (BTU) is the international measurement of energy. A BTU is the amount of heat required to raise 1 pound of water 1ºF Fahrenheit. In air conditioner (AC) jargon, a BTU measures the amount of heat an AC unit can remove from the room. As the BTU rating increases, so does the size, weight, and cost of the air conditioner. Room air conditioning units are generally 5,000 to 24,000 BTU. Matching BTU requirements to room size is important. The room(s) won't cool efficiently if the BTU rating is too low or too high for the size of the room.

EER

The Energy Efficiency Ratio (EER) is calculated by dividing the BTU by the number of watts. The higher the EER number, the more efficient the unit should be. A higher EER-rated AC will also be more expensive, so decide if the higher price tag is worth the energy savings you may be getting. The ratings range from 8 to 11.5. If it's really hot where you are, go for a rating of 10 or higher.

SEER

The Seasonal Energy Efficiency Ratio (SEER) rates the efficiency of an air conditioner during a typical cooling season. This is meant to give the consumer a more “accurate” representation of the efficiency of the air conditioner in “real-world” operation.

Thermostat

The heat-sensing thermostat adjusts the temperature of the air coming from the AC unit. They can be programmable or manual. An adjustable thermostat combined with a variable-speed fan is an effective cooling machine. AC units are available with a remote control, 24-hour delay timers and digital temperature readouts.

Filter

Clean air is essential for efficient operation. Look for units with filters that can be easily cleaned or replaced.

Fan

The fan moves the air. A variable-speed fan combined with an adjustable thermostat is an effective cooling machine. Look for louvers that adjust up / down and right / left.

Chassis

The chassis is the frame that supports the main parts of an AC.
Packaged Terminal Heat Pump / Air Conditioner: This type of large heating or cooling unit, installed through the wall, is used in hotel and motel rooms.

1. Determining the Proper Size Air Conditioner for Your Home

Many homeowners purposely buy an air conditioning unit that is oversized, thinking it will provide better or more efficient cooling. However, that is not at all the case; an oversized air conditioner is actually less effective — and, to make matters worse, it wastes more energy at the same time. It is extremely important to choose an air conditioner with the proper cooling capacity for your home. An AC unit with too much cooling capacity will be substantially less efficient and more expensive to run. A unit that's too small, on the other hand, will not be able to get the job done.

One other detail to consider is the intimate relation between cooling capacity and dehumidification. An AC Unit which is oversized will cool the air too quickly and will not run long enough to dehumidify the air it is cooling; this will result in a home that feels "cold and clammy." The size of your air conditioner is determined mostly by the details of the construction of your home; mainly living square footage, insulation value, orientation, and the number of windows. Other items to take into consideration are the number of people occupying the residence and its geographic location.

Typically, you need 1 ton of air movement for every 400-500 square feet of living space. A typical home in Yorba Linda, Corona, Rancho Santa Margarita, and Anaheim hills has about 2,000 square feet of living space, so a 3.5-4 ton unit would be sufficient. If you are unsure on the square footage of your home, you can find the information online fairly easily. Simply type in your address into a search engine like Google and select a link to a trusted source, like the assessor, or your cities web page.

2. Deciding on Your AC's Efficiency

After determining what size unit your home requires, consider its operating efficiency. It seems pretty obvious that an efficient air conditioning system consumes less energy and, therefore, costs less to operate. To measure your AC's efficiency, engineers have developed a metric called the "Energy Efficiency Ratio (EER)." Your AC's EER is computed by dividing its Btu/h (cooling ability) by the watts of power (how much energy it consumes) following test procedures set by the Department of Energy. Central air conditioning systems are also labeled with a Seasonal Energy Efficiency Ratio (SEER). The Seasonal Energy Efficiency Ratio rates the efficiency of an air conditioner during a typical cooling season. This is meant to give consumers a more accurate representation of the efficiency of the air conditioner in “real-world” operation. Federal Trade Commission regulations require that your AC's SEER rating be placed on the information label attached to the product. The higher EER/SEER rating is the more efficient the unit is.

When determining the SEER rating of your air conditioning equipment it is also very important you consult with your local building department and review city ordinance codes. Cities like Yorba Linda, Anaheim Hills, Rancho Santa Margarita, and Corona have minimum SEER ratings for central air conditioning equipment. Some cities, like Newport Beach, also have sound ordinances for outdoor AC units and require Title 24-HERS testing. Whole House Energy Rating (HERS) is a system implemented by the state of California where a home is rated on a scale from 0 to 250 to show its efficiency relative to a reference home built to just meet the Title 24 Building Energy Efficiency Standards' prescriptive requirements.

3. Is Your Home Ready for Your New AC System?

The final step is to make sure your home is properly equipped to receive the new air conditioner. First, you need to ensure you have adequate power running to the unit. Check your home's wiring for the right circuit amperage and voltage. Next, make sure the return and supply air is appropriate for the unit you selected. During this process, it is also a good idea to evaluate the condition of your ducts and repair or replace them if necessary. Ducts are responsible for distributing the air throughout your home and if they are torn the cold be pulling contaminants from your attic and disbursing them throughout your home.

Additionally, make sure fireplace dampers close properly and seal openings to the attic and around doors and windows. Finally, make sure that your new air conditioner is compatible with your current indoor evaporative coil and furnace. The most important part is to ensure that the condenser you are installing uses the same refrigerant as your coil, either R-22 or R-134A.