skip to Main Content

The Medical Doctor, the HVAC Guy, & the Crawl Space

Hvac Crawl Space Moisture Problems Md No Encapsulation

hvac crawl space moisture problems md no encapsulationSeveral years ago, I did a home performance assessment for a medical doctor – you know, the ‘real’ kind of doctor, not like those ivory tower, pie-in-the-sky, I’ve-got-a-theory kind of doctors who have PhD instead of MD behind their name. In his crawl space, I found all the usual suspects – insulation falling down (left), crawl space vents, uncovered ground, stuff growing – you name it.

Several years ago, I did a home performance assessment for a medical doctor – you know, the ‘real’ kind of doctor, not like those ivory tower, pie-in-the-sky, I’ve-got-a-theory kind of doctors who have PhD instead of MD behind their name. In his crawl space, I found all the usual suspects – insulation falling down (left), crawl space vents, uncovered ground, stuff growing – you name it.

I was a home performance contractor at the time and gave him a proposal that included encapsulating his crawl space. It was a big crawl space, so of course the cost to encapsulate was in the thousands of dollars. I showed him how good an encapsulated crawl space looks and told him about the benefits.

Crawl space encapsulation reduces moisture problems and saves energy.

He had some nasty looking stuff down in his crawl space, especially around the air handler of the HVAC system. Naturally, I showed him photos, including the one below. See that brown band through the middle, where the supply plenum connects to the air conditioner evaporator coil housing? That started off as white. It’s mastic, used to seal ductwork.

hvac air conditioner condensate pump crawl space moisture problems

Because he was a good homeowner who did his homework before signing a contract of several thousand dollars worth of improvements, he checked with his HVAC contractor. Who told him that what you see in that photo is perfectly normal, and he had nothing to worry about! And that was good enough for Dr. M.

Wow!

I didn’t think of this till later, but I should have said to him, “Dr. M, when you look at a smoker’s lungs and see all the gunk in there, do you tell them it’s normal and that they shouldn’t worry about it?” It’s only normal because of all the bad stuff they’re putting in there. Fortunately, with smoking, the tide turned long ago, and we know that what may be normal for smokers is far from healthy. Same applies to crawl spaces.

This Post Has 6 Comments

  1. It’s interesting how we will
    It’s interesting how we will spend thousands on granite counter tops, cars, iPads, and smart phones, but our respiratory health and comfort takes a back seat.

  2. I am amazed how much bogus
    I am amazed how much bogus information is put out by HVAC contractors. Not that all are bad. I am constantly having to re-educate home owners to help them understand why the info they were given was wrong.  
     
    I recently had a conversation with a guy that had spent weeks researching info on HVAC systems. He has talked to a dozen different HVAC contractors and everyone of them told him something different. I asked him if any of them discussed duct sealing or air infiltration with him and the guy looked at me like I was crazy. (In other words NO). What does it matter how efficient the units are if all the air you are paying to cool ends up outside?

  3. I just returned from a home
    I just returned from a home with a back drafting water heater where the HVAC contractor religned and capped the chimney for the furnace but failed to reconnect the water heater flue. And because the HVAC contractor checks the system every year, it has been ok. But now that we drilled a small hole to test drafting, it is our fault we have drafting issues. It took us awhile to bring to light that the HVAC contractors are not testing the CO level or draft of her units every time they come to the house. So my point is that it is amazing what people believe and think who is right without the facts.

  4. Yep, skunked by the
    Yep, skunked by the contractor “Exper”. I am an engineer with over 30 years experienced in investigating building issues of all kinds, including moisture intrusion. For one homeowner association, I recommended replacing T-111 with the usual obvious T-111 issues with siding. However, one member of the board opposed it because he spent some time and shared a couple of beers on his front porch with a “Pro” who could fix the T-111 problem by repairing it.  
     
    Wow, I went through five years of engineering school, tortuous licensing, and over 30 years of experience solving issues and continuing education. All I needed was a swagger, convincing pitch and a six-pack. Thankfully, the other members of the board were a bit wiser to the “Pro”. I sympathize Allison.

  5. Sam: Nope,
    Sam: Nope, this was no joke. It really happened. 
     
    Andrew: Yeah, priorities are a big part of it.  
     
    Jon: Sad but true. There are a lot of HVAC contractors out there who wear some serious blinders. There are also some who really get it and many more who are starting to get it. Transformation is coming to the world of HVAC, and I think some will be left behind and swept away. 
     
    Josh: Who’s a homeowner going to believe? That’s an important question, and if they have a good relationship with a contractor they’ve worked with for a while, it can be hard for a building science guy to come in and tell them the contractor was wrong because that means they were wrong.  
     
    Vic: Thanks for the link. I read the paper and don’t completely buy what they’re saying. Also, they’re not really concluding that encapsulated crawl spaces are a bad idea for the NW as much as they’re saying they aren’t cost-effective if you introduce supply air and that you have deal with radon. But they’re absolutely right to question the applicability of something that works well in one climate zone to a different climate. 
     
    Matt: Swagger and a six-pack, that’s all you need. Unless there’s a whole board involved, and you don’t share the beer with them. Yeah, this kind of stuff happens all the time. It’s VHS vs. Beta all over again.

Comments are closed.

Back To Top