Mid-Atlantic homeowners have a monthly incentive to increase their A/C efficiency – the electricity bill. You want to strike a healthy balance between the two extremes of expensively running the A/C constantly and cheaply making everyone uncomfortable. While no single remedy will make your electricity bill disappear, improving A/C efficiency and reducing your use of A/C will bring big savings.
Measuring A/C Efficiency
You already have tools available to you to determine just how efficient your Hagerstown-area home’s central air conditioner or smaller window units are. Two ways to check:
- Learn the SEER and/or EER rating of your A/C – The Seasonal Energy Efficiency Ratio (SEER) for central air conditioners is a measure over the entire cooling season of how well the machinery converts electricity into cooling capacity. Higher numbers mean greater A/C efficiency. Look for numbers above the federal minimum of 13, with Energy Star-labeled models above 14.5. High-efficiency models generally start at SEER 16. For window and through-the-wall models, Energy Efficiency Ratio (EER) gives you a comparable scale, with minimums of 9.8 EER.
- Compare electricity bills against cooling degree days – Cooling degree days tell you how often, and for how long, you probably needed to run the A/C. These data are often printed on your electricity bill. They are a measure of how long (in days) local average temperatures were above a given level (usually 65 degrees), and by how much. A day with an average temperature of 85 degrees equals 20 cooling degree days. Use cooling degree days to measure your home’s energy needs for cooling.
To increase A/C efficiency, consider your central air conditioner’s age. While proper maintenance can extend the lifetime of compressors, few will last more than 15 years, with average lifespans of around 12 years. Older, inefficient central air conditioners compare poorly to models available today through the federal Energy Star certification system. Energy Star air conditioners provide plenty of cooling power but use an average of 15 percent less energy than other models.
Replacing your outdated central A/C or window models will give a good return on your investment through improved A/C efficiency and lower electricity usage for the next decade. If new equipment is not an option, make the most of your A/C by attending to a few simple chores:
- Wash permanent air conditioner filters or replace disposable filters as often as monthly; inspect them frequently.
- Keep evaporator and condenser coils free of dust and dirt.
- Coil fins (the thin metal foil leaves) on the coils are easily bent, reducing airflow and hampering A/C efficiency; a fin comb is a handy tool for realigning these without fear of further damage to the fins or cuts to your fingers.
- Keep condensate drains clear on both central air conditioners and window models.
Annual inspection, cleaning and maintenance will keep your system running smoothly, improving A/C efficiency. While you can do the simpler chores for window and through-the-wall models, turn to your HVAC contractor to service your Baltimore area home’s central air conditioning system.
Seek Professional Advice
With significantly more experience working with more models than you could have, your local HVAC contractor can inspect your home’s entire system and help you adjust equipment and accessories to get the most cooling for the lowest cost.
At minimum, your service technician will cover these items:
- Check for duct leakage
- Measure airflow through the system’s evaporator coil
- Test for refrigerant leaks
- Contain any refrigerant that must be removed (rather than releasing it into the open air)
- Check for the correct quantity of refrigerant
- Oil motors
- Check belt tension for tightness and visually inspect belts for wear patterns
- Verify the thermostat’s accuracy
- Confirm correct electronic control sequence
- Verify that heating and cooling systems cannot operate simultaneously
- Visually inspect electrical connections and terminals, applying non-conductive, protective coating
If you do not already have them, get your HVAC technician to professionally install a programmable thermostat and set it for optimal energy efficiency.
Improve A/C efficiency by using your A/C less:
- Use natural ventilation with open windows as frequently as possible, closing up your home and turning on the A/C only when needed.
- Use ceiling fans to move air at higher temperatures, since moving air makes you feel cooler.
- Set programmable thermostats for 78 degrees, no lower.
- Keep all windows and doors closed when the A/C is running.
- Reduce indoor humidity (which your A/C must overcome) by using exhaust fans when showering and running hot water appliances (dishwasher and clothes washer) overnight, when the A/C is off.
For more tips on improving your home’s A/C efficiency, please contact us at Griffith Energy Services, Inc. We provide superior HVAC services to Baltimore and a wide swath of the Mid-Atlanatic region.
Written by Kevin Spain