How an Energy Audit, Some Caulk and Insulation (Total Cost $1175) is
Saving Me $1000... Per Year.

The following story is from an Infrared Diagnostic customer, and green blogger Tom Harrison who wrote on EnergyCircle.com about how his energy audit saved money. The following story is copied with Energy Circle's permission. Click to view source article.

By tharrison - January 22nd, 2010

Newton, Massachusetts is a pretty standard family home, but by making incremental improvements in air sealing, insulation, lighting, and with the help of a whole-house electricity monitor, I have been able to reduce its energy consumption by more than 50%.

Last May I had a home energy audit conducted by Flemming Lund of Infrared Diagnostics in Sudbury, MA. The results weren't entirely surprising; I didn't expect my aging suburban home to be completely leak-free and perfectly insulated. Nonetheless, the energy audit was extremely useful in pointing out several actionable, high-ROI steps that I could take to increase the energy efficiency of my home.

Next step, equally important: I got down to it. I installed blown in cellulose insulation in areas where it was deficient, air sealed cracks and gaps, replaced old weather stripping, and then had a follow up energy audit to assess what kind of progress I had made. The pictures below are from the two audits, and show just how much of a difference the work I had done made -- you can almost feel the increased warmth and comfort of the house where blue spots turned to red on the infrared images. 

Although Flemming calibrated the infrared camera to account for temperature differences between the two audits, It's worth noting that the outside temperature during the first audit was 50 degrees Fahrenheit and 38 degrees Fahrenheit during the second audit.

The following photos will take you through the steps that I took to improve the air sealing and insulation of our house.  Blown in insulation was all installed by hired contractors, as was much of the air sealing work.  However, many of the most significant improvements were made by myself -- looking back over the initial audit report, I simply retraced the steps on a cold day, found air leaks by hand (literally) and sealed them with a caulking gun. We'll start there. 

Air Sealing:

Here are just a few examples of where I did air sealing work:

This baseboard looks harmless enough; but because it hides a seam between building materials, it was a prime spot for air infiltration.

You can actually see the cold air leaking from underneath the baseboard into the living space. The solution was a bead of clear silicone caulk.

BEFORE: This image of the bulkhead door leading out of the basement shows how air was leaking around it. Flemming recommended I install an insulated door at the base of the stairs -- which seemed to me something of an expensive fix for such a seldom used location.

AFTER: Instead, I installed foam board at the entrance to the stairs. The follow-up audit showed that air was leaking around the duct tape I sealed it with, so I have since sealed it with spray foam -- one example of the value of a follow-up audit after having work done on your home.

BEFORE: The entrance to our attic was left open, other than a rickety interior door on the bottom of the stairs. All of our nice warm air (which rises) was escaping right up into that uninsulated attic.	AFTER: We fixed this problem by installing foam board over the attic entrance and sealing it tight.
BEFORE: This rim joist in the basement was another source of nasty air infiltration. Gaps in the framing lumber were letting cold air into the basement, which would then slip right up through the uninsulated basement ceiling into the living space.	AFTER: We sealed and insulated the rim joist with a closed cell spray foam, which serves as both an air sealing and an insulating material. Much better.
BEFORE: This basement window was a disaster. Flemming recommended replacing it with a new, energy efficient window, which would have been expensive. Saving that for a later date, I took note that the biggest problem was with air infiltration (dark blue) and attacked that first.	AFTER: Since the biggest problem was not with the insulating value of the window itself, but with the air leakage around the frame, I took the inexpensive way out by caulking around the wood frame. Although inside heat still permeates the glass, the air infiltration problem is largely eradicated (notice the warm areas around the window frame, where the arrow points).
BEFORE: This small gap along the rim joist may not look like much, but there was some serious air leakage coming through the gap along the rim joist.	AFTER: Sealing the rim joist with closed cell foam stopped air infiltration, while also serving to insulate the wood (which is a poor insulating material).

Aside from the very cool infrared images of improved insulation (posted below), perhaps the most valuable information gained from my follow-up audit was that these simple air sealing measures reduced my home's air infiltration from 0.87 NACH (natural air changes per hour) during the heating season to 0.42 NACH, and I have continued to make improvements since the second audit.

My air sealing work and the benefits it reaped confirmed my long-held belief that air sealing should be step one in improving a home's energy efficiency.  It's cheaper and easier than an insulation upgrade, and helps to ensure that insulation will remain effective (if air is permitted to move through insulation, it loses r-value).  It also goes to show that simply hiring a contractor to get the job done may not be the right course -- in my case, I think as much of the benefit came from simple things I did as from what the insulator did. 

Insulation:

Still, once air sealing is done, improving insulation makes sense and can add to the benefit by helping your house retain heat.  I'll let the following images speak for themselves:

BEFORE: This blue wall is but one of many examples of how our house was lacking in the insulation department. Whether it was improperly installed to begin with, or had settled after years of hard work, it needed fixing.	AFTER: We fixed the problem by having some blown in insulation installed from the exterior in this and other locations where the insulation was likewise inadequate. The result is a warmer, more comfortable house, as well as lower heating bills.
BEFORE: More insulation problems. The insulation in this corner of the living room had settled.	AFTER: A much more comfortable living room. We had blown in insulation installed from the exterior, and you can see the results.
BEFORE: More insulation -- the insulation in this corner had settled, as well. You might also notice the dark blue line at the seam of the walls, where a small gap between framing studs was left unsealed, letting in cold air.	AFTER: As you can see, the insulation problem is largely fixed. The air sealing problem, which could have been prevented during construction with a litle caulking, can only be fixed if we were to remove the drywall during a full-blown renovation. We'll have to make do.
BEFORE: More insulation. Eek.	AFTER: No problem.

Although insulation isn't necessarily the first step you need to take, we notice that there are no longer cold spots on the walls that create uncomfortable areas in the house.  As a result of our upgraded insulation, in addition to our air sealing work, the house is more comfortable, takes less time in the morning to heat up when the programmable thermostat kicks in, and our utility bills are much, much lower.

Lessons Learned:

Having taken these steps, we've also come to realize that there is no silver bullet: improving the energy efficiency of our house is an ongoing process -- there is still much to be done. The follow-up audit showed that there was still much room for improvement, and we have since taken steps in that direction. Some examples of where we initially fell short:

BEFORE: Flemming cited insufficient air sealing during installation accounting for the leakage around this dining room window, and recommended caulking both the exterior and interior sides of the window.	AFTER: Although I caulked around the window frame, the follow up audit showed only a very small improvement. I have since fixed the problem by adding foam to the sash weight cavity.
BEFORE: Another source of problems was our whole-house fan. Fantastic as a way to cool the house efficiently in the summer, Flemming pointed out during the first audit that it had an insufficient cover, so warm air could sneak right past it up into the attic.	AFTER: I added what I thought to be a real nice insulated cover to the fan, only to find out during the follow-up energy audit that the air sealing around the cover was insufficient. I have since tightened the seal with some leftover weather stripping, but it demonstrates once again the value of a follow-up audit.

Although the follow-up audit pointed out some problems that I missed during the upgrade, as well as some new ones that were overlooked during the first audit, it was also helpful in confirming that much progress had been made.

So what's the payback time for these improvements?

I will note that my gas utility, National Grid, had a program that paid a rebate of 75% of the cost of the air sealing and insulation, which made something of a difference.

That said, the numbers are staggering:

The cost of the audit was $400, the follow-up would have been $200.  The cost of the insulation after rebate was $475.  Materials for sealing (caulk, foam, insulation board) was about $100.  I can also deduct some of the materials cost in my federal tax return (maybe worth $50 or so).

So for a total cost calculation: I paid $168/month x12 before (2016 per year), and pay $89/month x 12 now (1068/year) for heat and hot water and stove (neither of the latter have changed), which means I will save almost $1,000 per year as a direct result of these improvements... every year.  It looks like this job had a one year payback.