Closet shelf material choice and indoor air quality
user-6758514
| Posted in General Questions on
At the risk of posing a question which depends almost entirely on budget and esthetic preferences, here goes:
In a house with, say, ACH50 of about 0.7 (final blower door test still pending) and HRV, what closet shelf materials are preferred or to be avoided in the interest of indoor air quality?
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I like the wire shelving (closetmaid, etc). It allows for air movement, which means less chance of mold or dust accumulation. If you are really worried, you can get industrial wire shelving made of stainless steel that will have zero issues with offgassing.
Bill
Most dust in houses comes from air leaks to the outdoors. It need not be a wire-frame- a flat shelf of an material & finish with low VOCs will do. There is very little dust finding it's way into a closet in a very tight house that uses (filtered) balanced ventilation.
Outdoor air is typically cleaner than indoor air, with the exception of pollen.
At work, I design and sometimes manage (under contract) datacenters and telecom facilities. These are almost like clean rooms inside, with continuous HUGE airflow (constant running about 2,000 CFM per ton of cooling) and big pleated air filters. We often run slight positive pressure in the equipment rooms to keep out contaminants. The rooms house lots of electronic equipment and very few people who maintain that equipment.
We replace the pleated air filters every 6 months or so. They always have stuff in them. Where does that dust come from? The two main offenders are paper products (which is why we don’t typically allow cardboard boxes to be opened in the equipment rooms, we have separate staging areas for unboxing), and dead human skin cells. The electronic equipment itself makes no dust.
I’d be willing to bet most dust in a home likely comes from similar sources, with the exception of any dirt that may be tracked in on people’s shoes and clothing.
Bill
>Most dust in houses comes from air leaks to the outdoors.
I am in the process of deconstructing a house and I would have to agree. It's a 1926 bungalow, it's perhaps the leakiest house I've ever seen. It also has epic amounts of dust. The ductwork is literally caked with dust. On one of the air handlers the filter was removed (I suspect because it had become clogged) and the coil looks like it's lined with velvet.
This also squares with my observation that leaky buildings will get dusty even when they are unoccupied. Tight buildings not so much.
I might modify it to say, "In houses that leak a lot, most of the dust comes from the air leaks."
I have a friend with a summer house in the Crows Nest Pass outside Calgary, near a coal mining area. The dust is like having a blower door test made visual. Each air-leak is a black stain emanating from all the usual suspects - window frames, baseboards, outlets, etc. As you say, most of it happens when they aren't there.
The other thing I'm noticing in this house is that where there is insulation (which isn't everywhere) there are black streaks along the gaps.
Coal dust was a huge issue in Pittsburgh back in the day. Coated everything with black dust. That’s a special case if you're dealing with it!
For more regular houses I’ve always seen the marks on insulation coming from air leaks going OUT of the house. I’m not sure where the black is coming from (the dirt we get in the air filters I mentioned earlier is a white/gray color).
Bill
Hi Chuck.
I agree with Bill that metal without a coating is probably the most benign of options. When I was researching this article, one of the experts I spoke with described the plastics that should be avoided, but ultimately advised that if you are concerned with indoor air quality, simply bring as little plastic into your home as possible. There are some good resources for low-VOC and less harmful building materials and furnishings in that article that may be helpful too.
I'll add, though, you probably know this if you are building a house that tight, that proper balanced ventilation is a must for healthy IAQ. More on that here: Balanced Ventilation Systems.
Thanks to all for these suggestions. Chuck
Nothing wrong with an unfinished pine boards
Walta