Air Purifiers Reduce Airborne Spores

Air Scrubbers

Room air purifiers can be useful in mold removal and mold clean up. Professional black mold removal contractors typically use commercial air purifiers known as "air scrubbers."

Negative Air Machines

When these air scrubbers are exhausted to the exterior, they are known as "negative air machines." Use of a negative air machine helps keep mold spores and other mold particulates from straying out of the work area into clean areas of your home. The machine also exhausts musty-smelling air.

Use of a negative air machine reduces the risk of "cross-contamination." When mold spores move from a dirty area to a clean area of your home, we call it "cross-contamination." Now the clean area needs to be cleaned, too.

Do-It-Yourself Negative Air Machine

If you are doing mold removal yourself and you don't have a negative air machine, think about setting up an exhaust fan in a window near the work area. This fan will help move contaminated air outdoors. Make sure this contaminated air isn't blown into a neighbor's area.

I'd recommend a box fan for the window, rather than the window fans with two side-by-side fans. The box fan would have more power. Make sure you aim the fan the right way and that air is blowing out, not in.

Open a window on the other side of the room from the work area for make-up air, to replace the air that is being exhausted by the exhaust fan.

Room air purifier for do-it-yourself mold removal

If you plan to purchase a room air purifier for use in reducing levels of mold spores, look for one marked "HEPA." Suggestions for purchase of a HEPA room air purifier include a Honeywell HEPA for a budget purifier. The room air purifier brand that is about the best-rated is the IQ Air.

Whatever type of room air purifier you might use during mold cleanup, consider replacement of the filters upon completion of the mold removal project. Wipe off the unit as best you can.

If you shop for a room air purifier, you may come across some models that are presented as large and powerful enough for an entire floor. Bear in mind that purifiers don't do corners that good. In other words, they basically filter the air around them, so you might as well just buy a room-sized unit.

Safe room concept

With the IQ Air, you could modify the unit for a "safe room." A safe room is useful at a house where there is no ductwork for circulation of air and where windows are kept closed. 

The IQ Air could be placed in a room next to the bedroom. A duct could go to the outside, to draw in fresh air. Another duct could go through the wall to the bedroom to deposit the filtered fresh air.

For sleeping, you'd have reduced particulates and fresh air, with the motor in an adjacent room. (Motors give off electromagnetic fields, and they are not recommended in the bedroom at night.)

Room air filters with carbon - mixed reviews

Some room air filters come with a 5-year supply of carbon. Carbon can be useful for absorbing odors, which HEPA filters do not do. However, eventually the carbon gets saturated and starts dumping odors. Twice I've been called to places because of an odd smell, only to find the source of the smell in the room air purifier.

Another issue with carbon is that mold and bacteria grow in carbon. The room air purifier could actually become a source of microbial growth, spewing out mold and bacteria into room air.

If you already have a room air purifier with carbon filtration, it could be contaminated if it was used in a below grade space. Change the filter medium and move it upstairs.

If your house is damp, I wouldn't use an air purifier with carbon filtration, unless, possibly, it also has UV light to kill mold and bacteria. Even with UV light, it wouldn't be my first choice of room air purifier, because the UV light wouldn't shine through all carbon particulates.

When a room air purifier is in use at a client's home, I always take air samples to see if the purifier is contaminated with mold or bacteria, whether or not the filter medium is carbon.

I seldom recommend room air purifiers for daily use.

Why would I seldom recommend a room air purifier, even though such a device has been popular with health-oriented customers for a long time?

The answer is that I believe a HEPA vacuum cleaner and damp dusting are more important for picking up dust where it settles. Also, if a room air purifier is on, the window should be closed, or you will be wasting energy by trying to filter the great outdoors. If windows are closed, you don't get fresh air and the oxygen that every cell in your body needs.

Thus, in the average house, my recommendation is to capture the spores where they settle in dust by HEPA vacuuming and damp-dusting and to open a window for fresh air.

Some folk, such as some with asthma, require the use of a room air purifier.

Tip: One of the biggest sources of particulate matter in room air is the carpeting. If you go to hardwood floors, you will eliminate a reservoir for allergens.

Controlled indoor environment

Many people never open windows, either by lifestyle choice or because of allergies. The same stale air is breathed, along with pooling of toxins off-gassing from household products, personal care products, and furnishings.

In office buildings, there is a requirement for fresh air and a certain number of air changes per hour. In residences, there is no such requirement. It is as if the heating and ventilation trade forgot that people have to breathe in their homes as well.

I sat in my office with a colleague one day, with the window and door closed. He data logged (tracked and recorded) the rise of carbon dioxide in the office as we talked. The graph went up, up, up, until I opened the window. Immediately the level of carbon dioxide started down.

This is what can happen in an airless bedroom at night as two people sleep. Oxygen is taken in, and carbon dioxide is given off. It should be no surprise that people wake up feeling tired. Every cell in the body needs oxygen.

For those who cannot open windows, there are other options for bringing in fresh air. For houses with no ductwork, the options are fewer. Look into the safe room concept already discussed.

For houses with ductwork, a duct could be run to the exterior for fresh air. The fresh air could be filtered (to remove pollen and mold spores) and dehumidified (so that damp air does not foster mold growth in ductwork). Lennox offers a whole house dehumidification system.

My colleague, Patrick Derrickson, a systems engineer, has conferred with the HVAC contractors (heating, ventilation, and air conditioning) of several of my clients in designing or retrofitting their HVAC systems with a whole house dehumidification system, fresh air source, and HEPA filtration for controlled indoor environment. Please e-mail me if you would like Pat's contact information.

may@createyourhealthyhome.com 

Many homes also have HRV (heat recovery ventilation) or ERV (energy recovery ventilation) systems. These are fine in a dry climate, but in a climate that is humid, they draw in humid air. My suggestion would be to explore dehumidification options to protect ductwork from moisture.

Do look into geothermal heating to reduce energy usage from dehumidification and heating/AC. Here are two resources:

www.igshpa.okstate.edu 

www.geoexchange.org 

For information on the EnviroHealth on-site inspection service with microscope, call 1-888-735-9649

CT-MD-NJ-NY-PA-VA, and elsewhere by arrangement

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