NADCA Quality Assurance Guidelines for Selecting a Commercial Contractor

  1. Can the company show proof of NADCA membership and certification?
  2. How long has the contractor been in the residential HVAC system cleaning business?
  3. Can the contractor provide you with evidence of the current Worker's Compensation and General Liability Insurance coverage? (Ask for Certificate of Insurance)
  4. Does the contractor posses the proper Licenses that are required by your city or state to perform the work they are proposing? (Not all cities or states require licenses.
  5. Can the contractor provide you with 3 to 5 customer references with phone numbers for projects of similar size and scope of work which they provided service in the last year?
  6. Does the contractor have written safety, respiratory, and confined space programs in addition to OSHA compliance reports?
  7. Will the contractor provide you with a means to conduct a visual inspection at any time during the cleaning? (Mirror and flashlight, camera or other remote visual systems)
  8. Will the contracting company actually do the work? (Some companies subcontract the work to independent contractors. You will want to apply these guidelines for subcontractors as well.)
  9. Will the company be assigning an Air Systems Cleaning Specialist (ASCS) to your project that will be responsible for the complete project?
  10. If there is any remediation of mold or other biological contamination does the company have a Ventilation System Mold Remediator (VSMR) on staff.

Commercial Service

One of the major causes of poor indoor air quality in commercial buildings is inadequate maintenance of air conveyance systems. For this reason, government agencies and indoor air consultants commonly endorse a "building systems" approach to indoor air quality. In order to reduce the threat of indoor air pollution, the building systems approach calls for a dedicated environmental maintenance program for air conveyance systems.

There are three main areas to consider in the building systems approach to good indoor air quality.

1. Ventilation.
The efficiency of the ventilation system has a direct correlation to the quality of the air within a building. Occupants within a building where air is not properly distributed to all occupied areas or where there is an inadequate infusion of fresh air into the system are likely to have indoor air pollution complaints. Also, ventilation systems which have accumulated large deposits of dust and debris may have air flow restrictions, which can seriously affect the comfort of building occupants and the efficiency of the system.

2. Filtration.
Most of the air filters found in today's commercial buildings are low efficiency filters. Thus, a large percentage of the dust, chemical residues, grease and other foreign matter carried in the airstream cannot be stopped by the filters, and ends up adhering to the interior surfaces of the air conveyance system.

3. Maintenance.
A good maintenance program for mechanical components in an air conveyance system is the key to preventing IAQ problems. For existing buildings, however, steps must first be taken to clean the air conveyance system and its components.

How Clean is Clean?

To some, the term "air duct cleaning", implies that just the ductwork in a system needs to be cleaned. However, only a total system cleaning, including all ductwork, fans, coils and other components, will yield positive results.

Naturally, if only a portion of the system is cleaned, the areas which were not will quickly re-contaminate the rest.

The National Air Duct Cleaners Association (NADCA), a nonprofit membership organization headquartered in Washington, DC, has introduced the first industry standard that quantifiably measures the cleanliness of an air conveyance system.

The NADCA Standard provides instructions on how to test surfaces within an air conveyance system for the maximum acceptable level of contamination after a cleaning job. This test can be performed by any qualified industrial hygienist, and serves to assure the building owner that the services he contracted for were performed successfully.

>>> Click here for the COMMERCIAL POST-CLEANING CHECKLIST (PDF Format)