Tag Archives: air conditioner

Up the chimney, all year long

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Fireplaces are fun, but lose conditioned air. Photo courtesy Grumpy Chris, some rights reserved.

Fireplaces can be great fun during the winter, providing ambiance and some added heat in the immediate vicinity. They can also be a huge waste of energy year-round. In weatherization we often talk about the “stack effect,” which is also commonly referred to as the “chimney effect.” In short (and greatly oversimplified), heat rises. During the winter warm air goes up and out through any and all holes. This is why sealing the attic is so important. Chimneys, however, are often overlooked. They are a huge heat loss during the winter and cool air during the summer, that is easy to fix and pays back immediately. Fireplaces and chimneys are straight shots from your climate controlled inside to the outside – a huge hole in your home’s ability to maintain the temperature you want. In the winter, whether you’ve got a fire raging or not, warm air goes up through the chimney outside, wasting energy and money. In the summer your cool air will do the same. Stopping that air flow is critical and usually, very easy. Usually the easiest way to stop the flow is with something called a “chimney balloon.” They are exactly what they sound like – a balloon you stick through your fireplace and into the chimney just above the flue. (You do have a flue, don’t you?) The most difficult thing is measuring your chimney interior to make sure you’ve got the correct fit. After that you inflate it the same way you do any balloon and it very effectively seals that hole but allows you to easily remove it if you want to build a fire in the winter. What happens though, if you can’t fit a chimney balloon? A few months ago we weatherized a home where the chimney was not only huge but had an irregular shape. A chimney balloon would not be able to seal this area. We didn’t want to give up though because this chimney was causing a huge waste of energy. We donned our thinking caps and came up with a cheap and easy solution that:

  • Stops the air flow,
  • Is removable if the owner wants to make a fire,
  • Looks good.

All pieces were purchased at local hardware stores – the only technical skills required were cutting the plywood to size and measuring the spot, a dozen times. Check out the video below shot and edited by Martin LaMonica, and let us know if you’ve got other solutions to irregular spots. -Jeremy

Cool in the summer part II – Its the humidity

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It's not the heat, it's the humidity! Photo courtesy TheKarenD. Some rights reserved.

That annoying saying, “it’s not the heat, it’s the humidity” is true. The heat wave we’re currently experiencing in Arlington is a double-whammy with high heat and high humidity (humidity was over 90% Saturday morning around 6 am.)

What to do?

To remove humidity from the house there is only one energy efficient alternative to an air conditioner or dehumidifier, but there are some important things you can do to prevent your home from becoming more humid.

The most efficient way to reduce humidity is to open a window, as long as it is dryer outside than inside. Even during heat waves (in MA) the overnight temperatures will usually drop, but humidity goes up. Environmentally, it’s a better deal to open your windows for the cool air and turn the AC off. Your air conditioner or dehumidifier are the only choices to reduce humidity in really sticky weather, especially during the heat of the day.

How to keep your home from getting more humid.

  1. Run your exhaust fans. When you shower or cook with gas, you release water molecules into the air -the last thing you want to do in a heat wave. (It also adds various unhealthy gases.) Turn on the exhaust fan while showering/cooking and make sure it stays on for several minutes after you’re done. Make sure your fan exhausts outside rather than into your attic, which creates a mold issue. If you don’t have an exhaust fan get one soon, your home will thank you.
  2. If it is still hot and humid in the morning, then contrary to what I said in a previous post,  keep those windows closed. Most online weather sites will tell you the humidity outside.
  3. Buy a hygrometer. Hygrometers (commonly, but incorrectly, referred to as hydrometers) measure the humidity in your home. Unfortunately the inexpensive models seem to be of poor quality. I’ve found them to be off by as much as 10% when testing them (testing/calibrating requires only salt and water, Google: calibrate hygrometer). You can buy decent digital models for around $20.
  4. Dehumidify. Depending on which “expert” you listen to your indoor humidity should be between 30-60%. This keeps your home more comfortable and prevents mold from growing. Dehumidifiers are costly to run but less expensive than mold damage or health issues. Unfortunately dehumidifiers produce heat, so during heat waves they’re best left in the basement.
  5. Air conditioners don’t just cool the air, they take moisture out. Use them wisely, set them at high temperatures (75+), and try to use all the energy saving methods listed earlier first.

-Jeremy