We are purchasing an old house built between 1840 and 1850. The house has had some work done throughout the years including: plumbing, electrical, blown in insulation in attic and wall cavities. What is the best recommended way to identify what gives biggest benefit from an air sealing / insulation perspective. Does it even make sense to pay for an energy audit knowing that there will be some significant issues or are there specific items to address proactively? We do not close until later this month, so I do not have many details on what insulation is in the wall cavity, etc. Looking forward to the experience. Ian. Not sure why avatar is upside down. ??

Home is located in Peninsula Ohio (44264).

Hire an independent Energy Auditor and tell him beforehand that you want the infiltration places identified. Walk around with him and see where the infiltration is coming from.That will be worthwhile.

Thanks Bob. If local energy company has subsidized audits are you suggesting to avoid them?

Are results biased to their advantage?

Ian.

I know nothing about your local energy company. I do know that some companies that do energy audits concentrate on what they do well. My son, in a distant town, had an audit done by a local heating company who then recommended a new furnace and water heater, which he could not afford, so he put the report on the shelf. So I asked him what the blower door result was, he didn't remember. When he found it, it was awful. But the auditor did not suggest he patch air leaks, or seal the cracks. I did, via a phone audit; ("it's very leaky here...") & sealing those leaks actually helped a lot.

The results are not biased, but one thing he really wanted and needed to know is where the leaks are and how he could fix them. Of course it helped to know the condition of his heating appliances, and if or when they need replacement, but he needed more information than that and it was not readily forthcoming. I've seen the same thing with companies around here. When an insulation company does an audit for less than the retail cost, one reason they do it is that there is an opportunity to sell insulation; same with a heating company. An independent who is not selling anything has no other reason to be there other than to help you figure out what the problems are. Get the subsidized audit, but do it with your eyes wide open.

I know nothing about your local energy company. I do know that some companies that do energy audits concentrate on what they do well. My son, in a distant town, had an audit done by a local heating company who then recommended a new furnace and water heater, which he could not afford, so he put the report on the shelf. So I asked him what the blower door result was, he didn't remember. When he found it, it was awful. But the auditor did not suggest he patch air leaks, or seal the cracks. I did, via a phone audit; ("it's very leaky here...") & sealing those leaks actually helped a lot.

The results are not biased, but one thing he really wanted and needed to know is where the leaks are and how he could fix them. Of course it helped to know the condition of his heating appliances, and if or when they need replacement, but he needed more information than that and it was not readily forthcoming. I've seen the same thing with companies around here. When an insulation company does an audit for less than the retail cost, one reason they do it is that there is an opportunity to sell insulation; same with a heating company. An independent who is not selling anything has no other reason to be there other than to help you figure out what the problems are. Get the subsidized audit, but do it with your eyes wide open.

Ian,
Duke energy in our area does energy audits and will help pay for added insulation, duct sealing and upgrade HVAC systems

Thanks Chris.

I will check into programs with local energy company.

I am not even sure who my provider will be.


Ian.

Test

In general, with the houses I've seen, the biggest environmental & comfort change is with two things: air sealing, and basement upgrades - by air sealing, insulating the stone walls and drying it out if damp or wet. This work i not necessarily quick & cheap, but it can be a huge improvement in the house.

We just took possession on Saturday. Had a peak in the attics. 1 looked pretty good, the other did not...

I spent some time poking around in the basement this past weekend. Air sealing around the sill plate (8" X 8" beam on top of a stone foundation) looks to be lacking.

Spray foam around the perimeter is the normal solution in a stick framed house, but I am concerned about the drying ability of such a large beam with closed cell on the inside. I did read the building science articles, but am not sure about going to this extreme jacking up and adding the capillary break, interior drains, full wall insulation.

Should I be concerned with closesd cell in this area?

http://www.buildingscience.com/documents/insights/bsi-041-rubble-foundations

http://www.buildingscience.com/documents/insights/bsi-045-double-rubble-toil-trouble

Up to 2" of closed cell does far more good than ill on the interior side of a foundation sill beam in an OH climate. At 2" the vapor retardency of the foam is comparable to that of the kraft facer on a batt, which is protective enough from wintertime moisture drives from the interior, but would also allow some drying toward the interior if you keep the RH in the basement low enough.

Stone foundations drain well and don't wick moisture up to the sill beam the way stacked brick or poured concrete foundation does- a capillary break is probably overkill unless you're literally in a swamp. Is there damp soil or pools of water in the basement? Does it constantly smell of mold? If it's pretty dry, it's fine to just foam over the entire wall with a couple inches of closed cell foam, skip the EPDM & capillary break.

Roof overhangs to limit splash-back, roof gutters, and a grade that drains surface water away from the foundation limits the amount moisture drive from the exterior.

Thanks Dana - The basement seems to be generally pretty dry. We did have some long rains last weekend (had to replace a sump pump) but I only saw 1 area that weeped a bit of water. I would like to think that it was because of the sump issue and the water level got too high underneath the slab.

There is some odor factor going on, but I am almost convinced that was from the fiberglass / 0.5" pink foam and some cellulose in the joist spaces in the basement ceiling. I found a dead mouse, some mouse scat and evidence of a small rodent homestead.

Glad to hear about the spray foam. I am meeting with an insulation contractor next week to look at basement, crawl and the attic spaces.

I purchased a humidity meter from the depot and it read a pretty consistent in the 50-60% range. What range should I be looking for?

Ian.

You have to correllate the RH% to the temperature, or it's a meaningless parameter. Then look up or calculate the dew point of that air, and compare it to the outdoor dew point.

In the cooler weather the dew point of the basement air will be higher than the outdoor dew point, even in a very dry basement. But in warmer weather the dew point of the basement air should roughly track that of the daily or weekly average outdoor dew point. In any season or basement temp a dew point less than 55F would be good, but it's not a disaster if it hit's 60F. If it's tracking the outdoor dew point too closely it means you're leaking a lot of air.

With a dirt floor and an unsealed uninsulated foundation I'd expect the basement's dew point to run on the high side, but with a ground vapor barrier and an air sealed insulated foundation it should track the dew point of the fully conditioned space upstairs.