Cleaning & Maintenance Management Online

Clean for Health

September 19, 2010

In the 19th Century, miners lowered canaries into mineshafts to check the quality of the air. If the canary died (or became sick), they knew the air in the mine was not fit to breathe.

Are your customers getting sick from the air in the buildings you maintain?

If so, it may be because they are breathing in dust, which means it’s time to help clear the air with better cleaning and maintenance practices.

To start, help your customers set goals. While dust control and indoor air quality (IAQ) maintenance may seem nebulous, measuring and defining objectives is achievable.

For a good example, look at industries where IAQ is carefully controlled — such as in high-tech manufacturing or computer data centers — and note how objectives are achieved.

Defining a goal
In an ISO Class 3 cleanroom used in manufacturing delicate electronics, the goal is to maintain an airborne particulate level of no more than one .5-micron particle per cubic foot of air. By contrast, a typical office space may average 30,000 to 50,000 .5-micron particles per cubic foot of air.

Know how to measure “success”. In the cited example, the objective is specific and measurable.

Ideally, readings are regularly taken using a particle counter, a hand-held device that counts the number of airborne particles. Particle counts are compared with established safe norms, and corrective steps are taken as needed.

High-end remedial measures
Remedial measures in data centers and peripheral areas take two forms: Source-capture and room cleaning systems.

Source capture is capturing particulate at its source before it can enter the air. For example, in data print centers using large, high-speed laser printers for data output, this often means capturing dust directly within the printer cavity using a filter and fan unit at the juncture where paper passes through and creates dust.

Room cleaning is attempting to remove or filter out contaminant after it has passed into the ambient environment. This method is less effective than source capture because it focuses on a cure rather than prevention.

Contaminant dispersion patterns
Studies indicate that the way contaminants disperse into ambient air makes airborne particulate difficult to effectively remove.

According to Larry Mainers, an expert in cleanroom and data center cleaning from the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE), particulate mixes completely with ambient air three minutes following release into normal air circulation.

In a sense, released dust behaves much like an oil spill. In the ocean, when an oil spill — driven by tides and currents — disperses into and permeates the surrounding environment, cleanup efforts are often ineffective, since the oil tends to fan out rapidly and prevent easy containment and removal.

Since released dust particles spread out rapidly into the ambient environment on currents of air, much of the “damage” is already done before remedial methods can have an impact.

People inhale particles in the 10-micron and smaller range, which is the size of particulate often passing through vacuum cleaners and settling on equipment and building furnishings to later be removed — to the extent possible — by cleaning personnel.

Does HVAC help?
Heating, ventilation and air conditioning (HVAC) systems sometimes fail in the timely removal of airborne dust because the volume of air processed is often relatively low. By the time air is passed through the HVAC system, building occupants and furnishings have often already been exposed to dust particles, similar to the way the natural environment is exposed to oil droplets after a spill.

Also, though air-handling units can dilute airborne particulate by introducing varying amounts of outside air, this raises costs for heating and cooling without addressing the source of the problem.

Realistic expectations
While it isn’t necessary (or possible) to keep your customers’ indoor air as clean as a cleanroom’s, establishing benchmarks allows making and measuring improvements.

This process can be as scientific as counting airborne particles with an electronic device, or as simple as passing a “white glove” over a surface to check for settled dust and saving the sample in a vial to compare with the next “test”.

Benchmarking may also be done empirically by surveying cleaning workers and building occupants for their assessment of “before and after” dust levels on furnishings.

By checking and recording dust levels consistently, you can determine how well your IAQ program is working.

Practical source capture
Since source capture, or prevention, is the best method for improving IAQ in stringent settings such as cleanrooms and data centers, how does it apply to less demanding facilities? Source capture, in connection with vacuum cleaners, is a vital strategy for keeping indoor air clean.

This means ensuring good vacuum filtration.

Without adequate filtration, vacuum cleaners — acting as “dust pumps” — are often a source of enormous airborne particulate. The finest particles suctioned from the floor and other areas are blown through ineffective filters into ambient air.

Source capture:
Counting the cost

While newer, high-efficiency vacuum filters are very good at trapping fine dust particles at the source, efficiency comes at a price: More filter maintenance.

This is because fine-mesh filters often clog more rapidly, reducing airflow and suction, and require more attention to maintain peak efficiency. The partial exception to this rule is micro filters, now popular in commercial vacuuming applications.

Though these efficient filters resist clogging, and sustain airflow longer, filter cleaning and maintenance is still essential.

Remember:
Prevention is first step

Whichever systems you employ to improve IAQ, keep in mind that prevention — capturing dust at its source before it’s airborne — is key.

Helping your building occupants prevent airborne dust will make the indoor environment healthier and more attractive, provide a model for other facilities to follow, establish you as a knowledgeable source, and help keep customers from suffering the fate of the canary in the mine.

Larry Shideler is CEO and chairman of ProTeam, Inc., Boise, ID. He can be reached at (800) 541-1456.