How to air-condition your home responsibly
Cooling your home in the summer can use a lot of energy. According to a recent article in The Washington Post, air conditioning use in places such as China and India is starting to boom, and in the United States, the habit of cranking up the AC continues unabated. But in a hot summer, cooling indoor spaces can seem indispensable to occupant health and comfort. How do you ensure that you are using your home's unit in a responsible manner?
- Have an energy auditor test your home's envelope.
- Insulate and seal as well as you can. You may also want to check your air ducts for leakage and seal the ducts. Ask an installer to calculate your cooling load after the insulation.
- Once you have a good sense of the BTUs you will need, then you can shop for a new AC system, if necessary. The air conditioner's SEER rating is key: the higher, the better—16 SEER is good, 18 SEER is great and 21 SEER is the best you can get.
Other tips for cooling efficiently
- Get the right size. If you are buying a new system, make sure to get the size that's right for your needs. An oversized system will short-cycle without removing the humidity and will result in poor performance, clammy air and a high cost in energy and equipment.
- Clean the air filter. Efficiency in an existing unit is greatly enhanced by keeping up with your maintenance.
- Get a greener system. Since 2010, HVAC manufacturers have not been allowed to make systems using ozone-damaging hydrochlorofluorocarbons (HCFCs). Although there are a few of the HCFC-22 (also known as R-22) air conditioning units left in circulation, they are increasingly rare. If you're thinking of upgrading, you can benefit from the advent of the environmentally friendly refrigerant R-410A, the new version of Freon that does not contribute to ozone depletion. The 410A products come with several different brand names, such as Puron.
- Turn it up at night or when you're not home. When you're sleeping, you probably don't need the AC as high. Turn the thermostat up a few degrees, the same way you'd turn your heat down in the winter. Similarly, when you're absent, there's no need to keep the temperature below what's comfortable for your pets or optimal for keeping mildew at bay.
- Close basement vents. Keeping the lower level of your home cool is usually easy without even using AC. Close off the vents during the hot season.
- Do chores in the evening. Use heat-generating appliances such as dishwashers and laundry machines during the cooler hours of the day, after sunset.
- Block the sun from windows. Things like shades, awnings and bamboo screens can all keep the sun out during the hot months—and therefore keep your AC from working so hard.
- Incorporate fans. Using fans strategically can reduce your need for blasting the AC at all.
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