Indoor Air Quality


Staff member
There is a debate going on (I think in Biz Week forum) that the Indoor air quality in large office buildings are very poor and that it makes people sick, headaches etc.

In winter, in residential houses the same situation occurs - breathing the same recirculated air with germs breeding in the ductwork. What are your thoughts?

Bad air is really not a laughing matter. I can tell you of one such experience. People would come and after about a week of exposure would start getting sniffles, like they were getting a cold. Or starting to get the flu. You know that blah feeling. What it came down to was bad air. Air conditioning that is. The ducts were full of mold. Quite a few different kinds. Took'em a couple of weeks to get rid of it. I was blessed; it never bothered me though many around me suffered.

This lead to an investigation as to why. What was revealed was that in this case the air conditioners were working well. There was a lot of travel, in and out of the building. Supplies moved in and out. Some people could not stand the spores and would purposely leave doors and windows open, even though it was air-conditioned. This lead to a collecting of moisture within the ducts, which gave the mold a place to grow.

Many homes today have been really insulated well to conserve heat/air conditioning and save on the utilities. This creates a near air tight area and then the temperature changes help bring in the moisture. Manmade material used in construction of the building/home is another source. Some of the glues used to hold together plywood and paneling, to put the paneling up on the interior. The carpet, the undercushion, glue to hold down counter tops, some floor coverings, paint and thinners. All are terrible for your health, especially when put into an environment where it can not dissipate.
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The hell with office buildings and homes. How about hospitals? They've become the breeding grounds for some of the nastiest bugs around!

A few years back Terri Gross, National Public Radio, was interviewing a doctor who was with Doctors Without Borders and had just come back from Africa, Ethiopia I believe, and commented after he had described the operating conditions (worse than a M.A.S.H. unit from the sound of it): "The infection rate must have been horrific."

I'll never forget his reply: "Actually, quite low."
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I have got sick after being in a mall for a while...

Plus after an hour or two my eyes get really tired and cloudy, been doing that for years at malls. Weather this can be attributed to poor air quality is another issue. Just wanted to type.
This may help to understand what is going on:

Most all office buildings, hotels and hospitals are sealed systems. The building code says that the HVAC (Heating, Ventilation and Cooling) system must have so many complete air exchanges per day. That is the entire volume of air should be replaced by fresh air so many times a day (numbers vary by the state). This is accomplished by an outside air inlet and controlled by a damper. Even the hotels that have individual AC in the rooms have vents to accomplish such task.

Now, if you exchange the inside hot or coll air with outside cool or hot air (respectively due to winter or summer) then there is a large energy use to do that. So, even though it is against regulation, the building people do not set it up correctly to save money (lots of money). Some places it is completely closed off hoping no one will notice. In large hotels, you have to stay there more than two days under this scenario to see you are getting a headache. If you have any suspicions, and happen to call the local health department, they normally setup schedules for check up. By that time it is all fixed.

My recommendation:

1. Hotels with independent room AC: Crack open the window about one centimeter (pinkie finger) - should do it. If the windows do not open, you have to open the top cover of the AC and find the vent control and set it to open position.

2. Office you work at: If it feels stuffy on mondays - it is bad. By mid week, the vent is open very little. Complain to the building maintenance to check it out.

3. Hospitals: Do not go near a hospital unless your life depends on it - then you take a gamble. Hospitals in south are worse due to moisture. I can not help here.

4. Home: In winter time, the home is air tight. So open an window time to time to get some fresh air. Use the bathroom and kitchen power vent if they are vented outside. Then you can crack open one window to get fresh air. To reduce the chances of bacteria and viruses, you can install a germicidal lamp inside your air return system that can kill any airborne bugs. If you install one, leave it all winter long on.
Neat ... but ...

I thought that's what heat-exchangers were for, kmguru.

Cut down on the energy loss by having the incoming air take heat from the outgoing air in Winter and be cooled by the outgoing air in Summer.
Only if you have designed and installed such a system with a fresh air heat exchanger. Most old buildings do not have it. The air to air heat transfer is very poor and people shut it off. In hotels all those window units have no such thing. To do a better job, you may need a air/liquid/liquid/air exchanger but I doubt they use it.