Is Central Air Conditioner the Smartest Choice for You?
Central air conditioners have many advantages over room air conditioners; they are more effective, out of the way and convenient to operate. It is wise to choose energy-efficient AC and reduce your energy bill; just for your information, the average air conditioned home consumes more than 2000 KW-hours or electricity per year. Best ACs use up to 50% less energy today, than they have used 40 years ago. You can save between 20% and 40% of your cooling energy cost by replacing a 10-year-old AC unit.
How Central Air Conditioner Works?
When the system is operating, the warm air is continuously circulating from various parts of the building back to the rooms after it cools. In this process, the system filters the air and removes airborne particles like dust and lint; filters that are more sophisticated can remove microscopic pollutants as well.
Types of Ducted/Central Air Conditioners
Two types of central air conditioners exist: either a split-system unit or packaged unit.
Split-System Central Air Conditioner
In a split-system unit the condenser and compressor are located in the outside unit, while the evaporator is located in the inside air handler unit. The indoor unit also contains the indoor part of the heat pump. This type of central air conditioner is suitable to install if your home already has a furnace.
Central Packaged Air Conditioner
With a packaged system, all the air conditioner components, the evaporator, condenser and compressor, are located in a single unit usually placed outside, on the grounding or roof. Air supply and return ducts connect with the outside AC unit through the wall or roof. Packaged AC systems often include electric heating coils or natural gas furnace, therefore eliminating the need for a separate furnace indoors.
This type of air conditioning system is an option to consider when you are looking for a ducted system and you do not have the furnace. It is also practical for small commercial buildings.
Selecting Appropriate Central Air Conditioner
Selecting proper size and quality installation of air conditioner are the most important factors influencing AC efficiency. If the unit is too small, it will not be able to satisfy your cooling needs on hot summer days. If it is too big, it will not adequately remove humidity. Improper unit location, duct installation and lack of insulation can greatly affect AC efficiency as well.
Seasonal energy efficiency ratio (SEER) is the measure of central ACs efficiency. SEER is representing the relative amount of energy needed to provide a specific cooling output. Higher ratio means better air conditioner.
National appliance standards require new manufactured Acs to have the SEER of 13 or greater after January 2006; these units are marked with Energy Star label. SEER 13 standard results in a 30% better efficiency, compared to earlier minimum SEER of 10. Older Acs, dated before 1990s, have SEER rating of 6 or less and if you are an owner of such AC, consider upgrading it for greater energy savings.
Other Features to Look For
Among other features to watch when buying a new central AC, you should look for:
- A thermal expansion valve and a high temperature rating (EER) greater than 11.6 for extreme hot;
- New ventilation systems with a variable speed air handler;
- quiet unit;
- Fan-only switch allowing you to additionally reduce energy cost by night;
- Filter replacement alert, a delay function that turns off the fan a few minutes after the compressor turns off.
Adding or Replacing an Older Central Air Conditioner System
If you are thinking to add central AC to your home, you must be aware of the importance of ducts. Many homes do not have air-conditioning ducts ready and adding them to existing home can be a difficult proposition and often requires remodeling of your home. If this is the case, consider buying a ductless mini-split AC.
If you are replacing the old central AC system with new one, or maybe only some parts of it, be sure that new parts (compressor, evaporator coil, condenser coil) will properly match and fit new air conditioning designs.
Installing and Operating Central Air Conditioner
Your AC can perform efficiently for years with minimum maintenance, if it you install it correctly. On the other side, improper installation can cause a modern energy efficient AC unit to perform poorly. Your contractor should perform the following procedures, when installing central AC system:
- Leave adequate space for maintenance and repair, and installs access door in the furnace or duct to provide a way to clean the evaporator coil.
- Use duct-sizing methodology like ‘Manual D’ of the Air Conditioning Contractors of America (ACCA) for example.
- Provide enough supply and return registers for air circulation.
- Install ductwork within the conditioned space.
- Seal and properly insulate all ducts.
- Locate the condensing unit in a shady spot, where its noise will not bother you or your neighbors, and where no nearby object will block the airflow.
- Verify refrigerant charge like specified by manufacturer.
- Locate the thermostat away from heat sources.