All About Central Air Conditioning: Here’s What You Should KnowPublished on: April 7, 2014
Are you building a new home or planning to replace your existing air conditioning equipment?
If so, a basic knowledge of how a central air conditioning system works, as well as factors that influence its efficiency and performance, will help you work with your HVAC contractor to select the equipment that’s right for your home.
Modern Energy Star certified central A/Cs use up to half as much energy as equipment that was built in the 1970s and 20 to 40 percent less energy than systems built just 10 years ago. You may be pleasantly surprised by the energy savings you see after investing in a new central air conditioning system.
How Does It Work?
Similar to how a forced-air furnace system works, a central A/C cools your home via a system of supply and return ducts that carry cooled air from the cooling equipment into your home and warmed air from your home back to the cooling equipment. A modern central air conditioning system is more energy efficient and less noisy, while providing better humidity control than cooling a home with several window units.
Central air conditioning systems can be built as split systems with the condenser coil and compressor housed in an outdoor unit and the evaporator coil installed as part of the air handler indoors, or as package units that include all of the cooling equipment inside a single unit on an outdoor concrete pad or mounted on the roof. In a split system, the evaporator is usually built into the main duct near the furnace (or air handler when the home doesn’t have a furnace). In a package system, insulated ducts connect the house to the outdoor unit.
It’s a good idea to take steps to improve your home’s overall energy efficiency before you decide on the size and type of cooling equipment to include in your central air conditioning system. If you spend a little money on a few of the following items, you may be able to cut the up-front cost of your A/C system by installing a smaller unit, and you will have lower monthly utility bills over the life of your home:
- Seal air leaks in your home’s building envelope. Caulk or spray insulation into holes in the walls, floors or ceiling where pipes or wiring penetrate between conditioned and unconditioned spaces. Seal around door and window frames, and add weatherstripping where moving parts of doors or windows come together.
- Upgrade your attic insulation if it’s not adequate for our Southeast United States climate. Adding insulation is a cost-effective way to reduce winter heat losses and to block summer heat from your attic from entering your home. Be sure your attic is well ventilated to minimize summer heat buildup.
- Have your ductwork inspected and repaired. Old ductwork may need repairs to reduce energy losses. Loose connections between duct sections should be fastened with screws or clamps, and seams and joints should be sealed with duct mastic or quality metal-backed tape. Any parts of your ductwork that run through your attic or other unconditioned spaces should be well insulated to minimize energy losses.
Sizing and Available Features
Here are a few other things to keep in mind as you work with your HVAC pro to design your central air conditioning system:
- Your cooling equipment should not be oversized or undersized for the expected cooling conditions it will have to operate under. Oversized equipment will start and stop frequently and give you unbalanced cooling and poor humidity control, while equipment that is undersized will not be able to keep your family comfortable on hot summer days.
- Include a programmable thermostat in your plans. Programmable thermostats let you set your air conditioning back to save energy during regularly scheduled times when nobody is home or everyone is asleep.
- If you are building a new home, consider including zoning dampers in your ductwork and individual zone thermostats for controlling the air conditioning in several different parts of your home. Zoning can save energy by keeping different parts of your house at different temperatures to better suit the needs of occupants, accommodate different cooling needs in different areas, and turn down or off the cooling in unused rooms or areas.
- Get a system that includes a fan-only mode so that you can ventilate your house without running the air conditioning compressor when the weather is mild.
- The outdoor unit should be in a location that is shaded from direct sunlight and that’s away from your bedrooms or your neighbor’s bedrooms so the sound of the system running will not be distracting.
Do you need help with your central air conditioning system? Contact us today to find a qualified contractor in your Southeastern U.S. community.