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Anyone catch the news story on 20/20 last night about the dangers of having a house “too tight”? I didn’t see it, but here is a link to the on-line summary:
http://www.abcnews.go.com/onair/2020/2020_000126_chimneys_feature.html
Be curious to hear what the reaction was of anyone who saw it…I find that when the TV “news magazine” programs try to do a piece like this, they do a somewhat shallow overview of the problems & solutions.
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Replies
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Per,
I didn't see the story either, but I'll bet I can imagine it . . .
According to the article and the transcript of the story, The reason is poorly installed furnace units and poorly crafted chimneys. It's not the windows, doors and insulation at all.
When General Contractor doesn't understand his job, things go wrong. But why didn't the HVAC guys install fresh air returns? Were they told not to? Were they too inexperienced to understand their own trade? Shouldn't the architect have noted where the fresh air returns are to be located?
It appears that the journalists have as good a command of their trade as the others (builder, architect, HVAC crew).
Just one of the many benefits of a low unemployment rate!
Dan
*>Depends on which example in the story you look at. I _think the point they are trying to make is that, in general, the tighter the house, the more likely to have backdrafting problems so the more need to be sure things are done properly.I haven't actually kept statistics, but in doing CO analyses on a number of homes, I've found that if my draft quage in the flue jumps when a door is opened (i.e., tight house) the more likely I am to find venting problems; low venting, backdrafting, etc. That's not to say there _will_ be problems, just that its more likely.It's not just tightness, though, A friend of mine did an investigation in a condo in which a couple had been killed by CO. The systems had already been checked by a number of experts who hadn't found anything wrong. When he checked, he found significant backdrafting when the attached garage door was opened. The couple had left their garage door open the night they were killed.<>Maybe its just the area I'm in, but I've seen some really stupid HVAC work. E.g., old house with sidedraft added to the attic; (almost inaccessible - gonna get real good service); flue running dead level about 16 - 20 feet to chimney with maybe 4-5 rise above the connection.After running the furnace for less than 1/2 hour, the CO levels in the attic were 35 ppm directly below a thru roof vent (which was pulling air in!!) and CO levels in the 2nd floor were 18 ppm. Whoever did that installation could've killed someone or crippled tham for life. (The house was vacant I have no idea what the prior owner's situation was.)I did one CO analysis immediately after one of the local "name" company's finished their installation (I had to wait while they finished up and rushed out the door.) Flame looked great, but it was pumping out about 1,200 ppm. Nothing spilling at the time, but in the right circumstances, who knows?Bob Walker
*I can't speak for all brands, but the installation instructions for most heating systems CLEARLY describe the venting and fresh air requirements. They're usually excessively safety intensive and I really don't think it's possible to seal a house so tight that backdrafting could occur. Far as I know, these installation instructions are also considered law (not recommendations) and are supposed to be verified by the building inspector.But... And I REALLY hope this is a local thing - I don't want to offend any of the TRUE tradesman.The HVAC (plumbers) around here live in a world all their own. The rule of thumb appears to be get in, get out and return repair business is good business. Until someone complains, there is no such thing as an improper installation. Often the Building inspector relies on the quality of the plumbing outfit to certify that the job was done to specs. The plumber (one of those "quality" outfits) who ran the gas line to my boiler plumbed it to the boiler drain, not the gas input. We all had a good chuckle over it, but sadly that was typical of the quality work in general. I suspect most home owners (and building inspectors) never even see a copy of the installation requirements to question the work. Mind you, most home owners probably wouldn't care anyway.I'd hate to see the tight house reputation mired in the mud of the HVAC industry.
*Bob et all:I did not see the TV program, however I did read the article you referenced.Most all of the "sick house" articles and other info I read or hear about deal with backdrafting of combustion appliances and the like to produce a unhealthy in-house environment.My question is, what are the implications of the "too tight house" scenario in the case of a house with no combustion appliances, fireplace, etc.? Example: all electric house; heat pump, electric range & oven, no fireplace (or direct vent fireplace). Any insight you can share would be appreciated.Thanks,Matt
*A house without a fireplace.....ahhh, the shame, the pityMy point with this post was that the shallow newshounds will find the dark underside (read: "black lining on a silver cloud") of anything they can churn into a 5 minute story on national TV. I saw the preview of the show (they didn't mention CO, but, then again, they didn't have to given the "symptoms" they described), but didn't catch the whole thing. My concern was more along the lines that people/homeowners will be reluctant to efficiently seal up their house because they fear imminent death by mystery gasses (CO, Radon (RA?), you name it, they're worried). A weak analysis of the problem, which I believe this was, does nothing to improve knowledge. Hopefully, it increases awareness, but I'm not convinced. Come on! Someone must have seen this! It was on ABC primetime 2 nights ago.
*I saw the whole thing. IMHO, they didn't do as bad a job as I expected with it. They really didn't play up the "too tight" aspect as much as the advertising would lead you to believe. In regard to the house you guys are talking about,backdrafting was caused by a chimney (on a gable end)terminated a few feet below the ridge. Apparently this would have caused the problem regardless of the home's relative tightness. In another example a newly installed air conditioning system had the return placed about two feet from the furnace (providing domestic hot water) and when the two ran together CO was pulled into the return and dumped into the couples bedroom (and I assume the rest of the house). I don't remember the third example.Jerry
*Matt,<>From a CO point of view, the only concern would be running the self-cleaning oven when the oven is heavily encrusted: an electric stove in s-c mode can produce some significant CO.There are other concerns about tight houses, outgassing of varoius interesting chemical compounds from today's miracle products, etc. but I don't know much about that side of the issue.Bob
*I saw the show. Made my wife run out the next day for a co2 detector. I agree that they really didn't blame the 'tight house' thing, but more the installations, though I'm not sure that people watching the show understood that the problem was poor design and installation. The tight house aspect was more that in energy efficient houses, these problems are more serious and that people with tight houses have to be more cautious. Nothing wrong with that. But it still cost me for the co2 detector.SHG