Today’s heating and air conditioning units are incredibly efficient when compared to those from just a few years ago, much less those that are 10-15 years old. There is nothing you can do to change the design efficiency of your central air system but there are some things you can do to maximize the overall effectiveness of it.
What can be done now!
1. System cleanliness is very important. Regular, annual cleaning of the inside (evaporator) coils and the outside (condenser) coils is extremely important. The condenser unit is subject to weather, dust, debris from mowing, weeds or other obstructions. The inside unit is also subject to dirt accumulated from dust and pollen passing by the return filter. Keeping these clean is essential. In most cases this is a job that a homeowner can do with some instruction and care. If not, a reputable HVAC repair contractor can provide this service.
2. Use adequate return filters. The $1.25 blue woven fiberglass filters are good enough to stop a cat from entering the system but not much else. These are very inefficient. They let through most dust and pollen that passes by. In order to keep the system clean as mentioned above (not to mention reducing allergens, reducing dust on furniture, etc.) a much better solution is needed. Right now, HEPA (High Efficiency Particulate Air) filters are the best thing going. These filters are up to 99% efficient. Honeywell HEPA and IQAir HEPA are among some of the leading manufactures for these filters. There are also portable HEPA filters that can be placed in particularly dusty areas to help reduce the overall dust in the house.
3. Humidity control is also essential for air conditioning efficiency. In addition to an air conditioner cooling the hot, moist air, it also dehumidifies it. This process of literally removes moisture from the air. Cooling the air isn’t nearly as expensive with lower humidity as in higher humidity. Proper home caulking, sealing and windows play a huge part in minimizing humidity infiltration from the outside. To help reduce indoor humidity, always run bathroom fans when showering or bathing. Also run exhaust hoods when cooking. In areas of extreme humidity such as a basement, a stand alone portable dehumidifier will help the overall efficiency of the central air conditioning system.
4. Humidity is essential for heating. (What? We just talked about cutting humidity out in the summer, now we want to add it back in the winter? YES! Winter air is much dryer than the summer. Moist air at a certain temperature actually FEELS warmer than dry air at the same temperature. Therefore, having a central humidifier or room humidifier will allow you to comfortably lower the temperature of the heater. Don’t raise the humidity too high, though, to prevent issues with mold growth. Mold removal isn’t desirable.
5. Install and use a programmable set-back thermostat. This will allow you to adjust the temperature to different settings throughout the day. For example you can adjust air conditioning up or heating down a few degrees during the day while at work. You can also reduce the heat setting at night while sleeping. Programmable thermostats are cheap, easy to install and use and pay for themselves in short order. Most home improvement stores (Home Depot, Lowes, etc.) have a large selection.
6. Use portable air conditioning or ductless air conditioning in remote areas that are rarely used such as a game room, play room or basement. These portable air conditioning units work great for these areas where you only want to have the areas cooled on rare occasions. This is much cheaper than trying to cool these rooms all of the time.
What can we plan for!
1. Replace older units with newer units. While there may still be a 2-3 year payback on initial purchase, these units can cut cooling and heating bills as much as 50% compared to older units. Check with your local utility provider. Many offer grants, low interest financing or other incentives to get you to install more efficient units.
2. Investigate zone controls. Modern air conditioning controls make it very economical to break your home into heating and cooling zones, each with their own temperature and humidity settings.