Indoor Air Quality from Air Purifiers, Furnace Filters

Report On The Air Quality Clean Up In Our Offices

As I told you in the last newsletter we had been suffering in our new offices. The air quality was terrible and it had a smoky stale smell. We were dry coughing and had itching eyes and I, among others, had trouble breathing.

The Steps We Took:

1. Took baseline air quality readings with an air particulate monitor over a week’s period at 5 locations both inside and outside our building. We have highway traffic, a repair garage and school bus parking nearby. In other words the air quality outside is very poor.
2. Installed 4 IQAir Healthpro Plus and 3 IQAir Multigas free standing air purifiers in 4300 square feet of office space.
3. Took further air quality readings with our particulate monitors.
4. Got 4 competing bids from NADCA members in Massachusetts (where we are located) for duct work cleaning.
5. Had the ducts cleaned.
6. Took post duct cleaning readings.
7. Installed Guardian electrostatic air and furnace filters on the roof our building and fresh air intake.
8. Installed filters at our interior returns.

The Results

1. Our inside office air baseline readings before intervention were about 350,000 to 600,000 particles (greater than .3 microns) per cubic foot, with outside readings varied from 5 to 11 million particles (greater than .3 microns) per cubic foot.
2. Our inside registers/vents were averaging 3.5 to 6 million particles greater than .3 microns, dumping filthy air at an incredible rate into our office through 49 registers.
3. We put our IQAir air purifiers on high(6) at night and low(3-4) during the daytime. The air coming out of those machines registered ZERO on our monitors showing their superb efficiency, but the onslaught of dirty air was too intense for even IQAir to get the level of air quality down below 100,000 particles greater than .3 microns per cubic ft .on a good day, which was achieved WHEN WE TURNED THE FAN OFF. Mostly our readings were around 200,000 and even 300,000 particles greater than .3 microns with the fan on. When the fan was off, we felt colder and people were complaining that we should turn up the heat. The IQAirs were reducing the particulate count by 80 to 90 percent, but the baseline rate of recontamination was too high. We needed to attack the source of the dust.
4. We went with a NADCA registered duct cleaning company. After comparing quotes and what would be done for the money, we went with a mid range quote. It took 6 men 9 hours (54 man hours) to clean our duct work which included some of the next door office suite. I was around for most of this operation to observe the process. Their HEPA vacuums were the size of a large office desk. They snaked into the ducts and scrubbed the duct walls as well as hand cleaning and washing each register. They then peered down the ducts with a video camera device to make sure everything was clean. They sprayed the interior of the ducts with EPA approved biocides. The HEPA filters which had to be replaced along the way because they clogged up even so the air was filled with dust and remained that way for a couple of days until our IQAir air purifiers cleaned the air.The company doing the cleaning said the ducts had not been cleaned in 20 years. The dust was 4 to 6 inches thick inside the ducts and was the clear cause of the poor air quality in our offices.
5. We checked our air quality one week later. The monitor registered 34,000 particles greater than .3 microns per cubic foot, WITH THE FAN RUNNING so we had exceeded our goal. We have reduced our level of particulate contamination by over 95%. It will never be perfect, as we are constantly reintroducing pollutants into our offices.
6. For icing on the cake and to prevent further dust from accumulating in the ducts we installed our electrostatic Guardian Furnace Filters on the roof. The results of the Guardian filters will be tabulated over the next month.

My conclusions?

There is no doubt in my mind (and many of you have asked) that duct cleaning WITH CERTIFIED DUCT CLEANERS can be extraordinarily helpful. Our landlord did NOT pay for the ducts to be cleaned but did give us permission to do the remedial work. We used IQAir particulate monitors for monitoring purposes, which are available for sale if you phone us – they are not cheap, but we use monitors around here to test a variety of equipment.

I can now breathe, no-one is coughing, no-one is cold, we consider we have been very successful. In fact, David who was running the experiment was blown away as we far exceeded our goals. We have clean, and nice smelling air. All I can say is thank goodness, it was really bad before and a challenge.

National Air Duct Cleaners Association
EPA article on Indoor Air Quality: Air Ducts

Both resources give you a check list to see whether your duct cleaning service company has done a good job. NADCA gives you a list of certified practitioners in your area.

Furnace Filters: Guardian Furnace Filters
Air Purifiers: IQAir Air Purifiers