Monday, December 8, 2014

Why you need a home energy audit

I have a well deserved reputation as an energy efficiency and renewable energy guru and people frequently ask me what it would cost to put solar panels on the roof.  My immediate reaction is to ask them if they have done everything possible to ensure that their home is as efficient as they can possibly make it.   I point out that solar power systems are very expensive and in order to reduce the cost of that installation you first need to do everything you can to reduce the energy consumption within your home.  I encourage them to have a professional home energy audit done first and this can be done for between $300 and $600.   Some state utilities will do it for free, so do your research.   The quality of an energy audit will vary significantly from one entity to another, but bottom line they should provide you with a shopping list of things that you need to repair or change around your home starting with the "low hanging fruit" of the least expensive options and working up from there.

Blower door test in progress
While it is possible to do an amateur DIY home energy audit yourself, is really no replacement for a professional audit.  Professionals use a blower door test to find leaks in your building envelope, and a thermal imaging camera to identify energy leaks.  Several years ago, I followed my friends Paul and Topher around when they did an energy audit here in Maine, here is a link to my photo essay that details what they did and why.  The report they provided to the homeowner ran to over 10 pages and included a very thoroughly detailed analysis of their energy use and many suggestions for improving efficiency by reducing heat loss and energy waste.  

Here in Maine, typical low cost suggestions might include installing gaskets under the outlet and switch plates on the exterior walls to prevent cold air from infiltrating from the outside.   Next, you should look at weatherstripping the seal around your attic hatch.  Due to the chimney effect of warm air rising within your home, heat wants to exit at the highest point which is typically your attic hatch.  It is also quite inexpensive to weatherstrip around all your doors and windows to prevent cold air entering.  If you have a basement you should look very closely at any basement entrances or windows.   One way to dramatically improve the energy efficiency of your windows is to install interior storm windows.  Here are instructions on my website for making them yourself at a cost of around $1.25 per square foot.  Commercial interior storm windows can be custom-made at around $9/sq. ft. from AEP in Albany, New York.   Before my friend Topher came up with the DIY version, I installed some of the custom commercial panels in our home, here is a detailed overview that includes thermographic images showing how well they perform.

If your refrigerator is more than 10 years old, you may want to consider replacing it.  Refrigerators are the single largest energy user in the average home and newer refrigerators and freezers are a great deal more efficient than they used to be.  When shopping for any new appliance is important to look at the Energy Star label as a guide to comparison shopping.

Thermal camera showing cold air leaks
(blue) around our front door frame.
I did a thermographic imaging analysis of the exterior of my home and workshop several years ago and you may find it informative to review the images to see what I learned

In cold climates, it is essential to ensure that your attic is very well insulated.  If you can see the exposed top of the joists, then there is room for improvement.  You can add another layer of fiberglass bats across the top, or have a contractor blow in an additional 10 to 12 inches of cellulose.  Here is some helpful information about doing it yourself.


Self-installed solar power and heating
collectors on my super insulated
Maine workshop building.
Once you have achieved optimal efficiency in your home,  you will have significantly reduced your energy consumption and thus the size and cost of a solar power system .

I encourage you to get at least three estimates from local solar installers.  You can find solar installers in your area on the site.  There are multiple options for installing solar energy systems on your home and a qualified professional can explain them for you.  You may also wish to explore the systems I self installed on my home and workshop buildings.  If you are comfortable doing things yourself I suggest you start by looking at the Living Sustainably page of my site.