Saving Energy & Money in Hot Weather

You might live in the Arctic Circle right now – but if you live in the Northern Hemisphere, and haven’t seen a polar bear wandering by, then you may be “enjoying” a record heat wave that has befallen us. It’s currently 105 degrees in Nashville TN, so everyone here is cranking up the air conditioning. This can result in huge utility bills – but you can do some simple things to keep those costs to a minimum.

  • Look for and minimize every heat source in your home

There are multiple sources of heat in every modern household, but most people don’t do anything to minimize them. Your AC has to work to counteract everything that is warming your house – let’s go through a few ideas:

  1. Turn off or down everything that uses electricity or generates heat – stereo receivers, computers, TVs, refrigerators, dishwashers, even lights! They all generate heat inside the home, so keep them turned off, use dimmers on lights, or use them at night.  Even shutting off the pilot light to your furnace helps.
  2. Cover windows where you get sunlight during the day – blinds, curtains, blackout shades, and other covers can prevent sunlight from roasting your interior. If you can’t do this, then move dark objects out of the sun’s path (they absorb heat).
  3. Seal your house – this may be obvious, but it has to be mentioned.  Make sure your windows are sealed shut, your doors (and AC vents) have no air leaks, etc.
  • Make your cooling equipment more efficient, and don’t push it too hard

This is the big one during the summer – air conditioners work by allowing a pressurized liquid turn to a gas (which makes it colder), forcing warm air through cold coils, then recompressing the gas back to a liquid outside (which moves out the heat).  These AC systems can vary widely in efficiency (and cost you money) based on a few factors:

  • The SEER Rating of the AC unit – higher SEER ratings mean they use less power for a given amount of cooling.  In 2006, the minimum SEER rating for new AC units was raised to 13 from 10 – if your AC condenser is 10 years old or older, you will save double or triple what it costs you to upgrade to a 16 SEER condenser.
  • The condenser itself – go outside and look at the box with the big fan on top.  This device compresses the gas into a liquid, then cools it by pulling air through a long coil.  If the coil is dirty or obstructed on the sides, the air can’t move through it.  If you’re handy, you can take the fan off the top, clean and straighten the coil fins with a wire brush, and spray out any debris with a water hose.  This really helps. If the air still isn’t cool enough, have an AC guy check the refrigerant levels (either older R-22 Freon, or R-410A Puron).  That can really affect cooling.
  •  Make your AC work less – having the condenser sit in the shade helps, but there’s more you can do to de-stress your AC: replace your air filter regularly, close vents to rooms that you’re not using (then seal them off), raise the thermostat to 78 degrees or higher (every degree below 78 costs you 3-4% more), and if you have cool nights, open your house up to the outside air during the night, then close it for AC in the morning.  Some even use alternative cooling, like a box fan with ice on it.

Here’s a good video that explains how to optimize your AC unit’s performance: