Insulation Project: Comprehensive Energy Audit

6 11 2008

blowerdoorJimmy and John from ASK Construction came over to do a Home Performance Energy Audit (a comprehensive energy and safety inspection) of my home.

First they did a fairly quick survey inside and out to determine the overall volume of the house, including the size of all the windows and doors.

The Audit was divided into 2 parts: Energy Efficiency and Health|Safety.

The items they looked for in the Health|Safety category are fairly obvious but are often overlooked including:

  • Adequate Carbon Monoxide (CO) coverage: in addition to having a sufficient number of detectors, each needs to be located such that if one of them is activated, all the occupants will hear the alarm, no matter where they are in the house.  Suggested locations are: at the top of the Basement stairs in case there is a problem with the mechanical equipment and just outside the kitchen because when you turn on your oven, carbon monoxide levels of 700-2000 parts per million can accumulate until they are vented away by your hood exhaust.
  • They checked all the mechanical equipment in the house to see if there was any carbon monoxide (CO) leakage (there wasn’t any), and that there is adequate fresh air intake and exhaust (there’s plenty).
  • They checked to make sure all mechanical gas-fired equipment was enclosed in a fire-rated room (this item needs a little work).
  • They checked that the bathroom exhaust fans were working properly.  An adequate bathroom exhaust fan should run for 20 minutes after a shower to remove the moisture from the room. (Ours are pretty good – loud but powerful).
  • At the Basement, where we have a de-humidifier running all year round, they tried to determine where the moisture was entering from (I think it’s from along the side garden wall – more difficult to fix than if it was just the rear wall at the backyard) and we had a long discussion about what kind of exhaust fan to install.

Now for Energy Efficiency (!)

Heating/Cooling system: First they had me turn the thermostats for the furnace way up so they could check if there was any leakage in the air ducts.  Turns out that there was a 50% drop in pressure when they added up the measured supply of air in each room.  Unfortunately, these ducts are concealed in the ceiling – this wastes a lot of energy in both the heating and cooling seasons because a lot of conditioned air is wasted heating and cooling the duct enclosure so expect to see big holes in the ceiling sometime soon so we can get in there and repair the ducts.

Air Infiltration: Jimmy and John tested all the windows to make sure they were operational and then closed up all the doors and windows for the blower door test – that’s what is going on in the picture above.  The idea is to close up the house and then measure the volume of air that leaks in from openings in the building envelope and locate the source of those air leaks so that they can be corrected.  The red fabric shown in the picture is stretched over a temporary frame in the door (you can sort of see the digital gauge attached to the edge of the door that measures the air flow).  Jimmy said the air leakage in the house didn’t seem so bad but he wanted to do the calculations back in his office to confirm.

We have an opening in the ceiling in one of the bedroom closets in order to access some valves and it was totally screwing up the test so they taped the door closed to get the proper seal.  Apparently, it’s openings like this that can suck out your heat in the winter and conditioned air in the summer.  Closing up this opening will be a high priority.

Windows: John mentioned that our aluminum windows with double-pane glass, circa 1990’s could be improved.  I know that vinyl or wood windows are more efficient (vinyl and wood are better insulators than aluminum) and new double-pane glass comes with Low-E coatings and can be filled with argon glass for added efficiency but these types of new windows are VERY expensive and I don’t think they will fit in our budget for a while.  In the meantime, we will invest in high-efficiency double-honeycomb shades to better insulate at the windows.

Insulation: John made a small hole in the wall adjacent to the garden and found that it was PACKED with fiberglass insulation.  This is very good news.

Costs:

As for costs, the audit cost $350 which I believe will be refundable by the Home Performance with Energy Star Program if we do more than $2,000 worth of weatherization work (which seems likely).  Having completed the audit, we will now be eligible to take advantage of the incentives offered by the program which can be up to 20 per cent cash back on the total amount of eligible measures, plus federal and state tax credits.  The whole point of this exercise is to improve the efficiency of our home so we should also expect to see a large cost savings in our heating and cooling costs.

I expect the full report in about 10 days, after which we will start the corrective work to repair all deficient conditions.