Monday, January 28, 2008

Icicles, cracks, gaps and other indicators...

Americans, on average, invest more than 20% of their overall energy use in heating and cooling their homes and offices. That's thousands of gallons, cubic feet, and kilowatt hours of energy dedicated to keeping our bodies surrounded by an ambient 65-75 degrees.

Given our collective investment in comfort, the least we can do is to use that energy efficiently. As such, ChooseRenewables has identified 5 things you can do to heat/cool more efficiently. We borrowed a $15,000 thermal imaging camera so we could objectively identify inefficiencies in heating and cooling. We hope to save you the $15k by providing a few simple and readily identifiable indicators. Another option is to hire a professional to perform an energy audit of your home or office...

This post is a bit biased to those of us living in snow country. Fear not snowbirds since the same concepts apply to cooling a home.

1. Fill the cracks
Gaps and cracks in the exterior of a building allow preciously treated air to escape and wasteful warm or cool air to enter a conditioned environment.


The bright line indicates a significant amount of heat leaving my home. You can see that the surface temperature of the well-insulated siding is about 9 degrees, while the gap in the awning is over 30 degrees. Here's the indicator:

The two small dark marks in the picture indicate gaps. A closer inspection shows a clear gap between both boards. The solution - fill the gap with insulating foam like Great Stuff.

2. Close the gaps
This next one is the most embarrassing. Check out the veritable flood of energy escaping our home in near the walk-out basement.

There is so much heat escaping that it melts the snow.
Already embarrassed (and cold), I fled inside to identify the culprit of our energy loss. It didn't take long to see this glaring hole. The big indicator is the significant gap between the concrete floor and the wall. Luckily, this is a quick fix with insulating and expanding foam like Great Stuff.
I have a strong suspicion that filling that gap will also eliminate an entry-point for little critters. We'll consider that a positive by-product of saving energy!


3. Weatherstrip the windows and doors
Here's another easy one to fix. Check out the cool blue air entering our house from the garage.
It appears that the weatherstripping is doing it's job around the upper half of the door. However, we'll see some really energy savings from re-weatherstripping the bottom half of the door and installing a door sweep.


4. Insulate yourself from evil icicles
Worried about polar ice caps melting? Then you better work your magic to eliminate icicles from forming at your own home. That's right - the best indicator of heating/cooling inefficiency (i.e. cracks, gaps, and poor insulation) is ICICLES!

The bright yellow area next to the "purple" icicle indicates escaping heat. That escaping heat causes the snow to melt, which then leads to the formation of icicles.
To fix this, I need to fill the crack between those adjoining board with an insulating foam like Great Stuff. We're pretty lucky given the great insulation in our roof (we have SIP panels). For many homes, icicles will form around the entire perimeter of the home - indicating a general lack of insulation throughout the roofing membrane.


5. Close the fireplace flue
This is likely the easiest, and certainly the cheapest, activity that one can perform to eliminate heating/cooling inefficiencies. The thermal image below shows my fireplace with the flue closed and the ambient room temperature set to approximately 68 degrees (using an energy efficient programmable thermostat). The outside temp is approximately 10 degrees. The flue has been closed for at least 24 hours. As you can see, the surface temperature of the fireplace ranges from 58.2 to 71.2 degrees when the flue is closed with an average temp of 65.5 degrees. I subsequently opened the flue and took a similar photo about 75 minutes later:
After a short 75 minutes, the surface temperature range had fallen to 51.5 to 64.1 degrees - with an average of 57.8 degrees. So, by simply leaving the fireplace flue open the surface temperature dropped 7.7 degrees (or almost 12%). What a waste...

Here's our advice:
  • Inspect your home twice a year for cracks and gaps (once in the Spring to prepare for the cooling season, and once in the Fall to prepare for winter). Pay particularly close attention to adjoining walls/eves and trimwork. Look for any dark spots - and fill the gaps/cracks with sealant/caulking/insulating foam. We've had very good luck with Great Stuff!
  • Inspect your doors/windows once a year for adequate weatherstripping. We recommend doing this in the winter so you can actually feel the colder air entering around and under your door.
  • Rid yourself of icicles by better insulating your walls and roof. While icicles may be pretty, so are Polar Bears. And your icicles are indicative of your contribution to melting polar ice caps. Poor polar bears...
  • Enjoy the fireplace, but close the flue the following morning.