How to choose an air duct cleaning company in Pennsylvania

Updated November 10, 2026 · KeystoneProGuide editorial team

How do you choose an air duct cleaning company?

Make the company prove the job is needed, then compare at least three written estimates, and only then weigh credentials. That order follows the U.S. Environmental Protection Agency (EPA), which says not to assume that all duct cleaners are equally knowledgeable and responsible, and reminds homeowners that these companies are trying to sell a service.

This guide explains how to pick. It does not rank or recommend any business.

What should a company show you before you hire?

Evidence. When a company comes to your home, the EPA says to ask it to show you the contamination that would justify cleaning. Many parts of a heating and cooling system cannot be seen without opening it up, so if someone tells you there is mold or heavy debris, ask to be shown it.

A company that quotes without looking gives you nothing to judge. NADCA, the industry's trade association, advises asking contractors to come to your home, inspect the system and then give a quote, and suggests interviewing as many local contractors as you can.

Which claims should rule a company out?

The EPA is blunt about three sales lines.

• Sweeping health claims. The EPA says not to hire duct cleaners who make them, because such claims are unsubstantiated.
• Cleaning as routine maintenance. The EPA says not to hire duct cleaners who recommend duct cleaning as a routine part of looking after a heating and cooling system.
• A claim to be EPA certified. The EPA says to be wary of anyone who says this. It neither sets duct cleaning standards nor certifies, endorses or approves duct cleaning companies.

NADCA adds a fourth: being told, without a proper inspection, that mold or other dangerous substances are present in your system.

What do NADCA membership and certification mean?

The EPA does not certify duct cleaners, so the credential you will hear most often is the trade association's. It helps to know what it does and does not cover.

• Membership belongs to the company. NADCA says members must have at least one certified Air Systems Cleaning Specialist (ASCS) on staff, carry general liability insurance, agree to clean to its standard, known as ACR, and follow its code of ethics.
• Certification belongs to a person. NADCA says its program certifies individuals, not companies. There are no formal prerequisites for the ASCS exam, though NADCA recommends two to four years of field experience first, and the certification has to be renewed every year.
• The standard is public. NADCA released the 2025 edition of ACR in September 2025 and says it can be downloaded free of charge. It covers inspection, containment, cleaning methods and ways of verifying that a system is clean.
• Claims can be checked. NADCA says some companies falsely claim membership or use its logo. It gives each member a certificate showing the company name and the date membership expires, and says you can confirm membership in its Find a Professional directory or by contacting its headquarters.

Two cautions. NADCA is the industry's own body, so membership is a commitment a company has made, not an outside inspection of its work. And NADCA says a member that is not going to clean to the standard on a given job must tell the buyer at the time of sale, so ask that question directly.

The EPA, for its part, says to interview companies to make sure they comply with NADCA's standards and, where ducts are made of or lined with fiberglass, with the recommendations of the insulation manufacturers' association, NAIMA.

How do you check a company in Pennsylvania?

Pennsylvania has no state license for most contractors, according to the Department of Labor and Industry. What it has is home improvement contractor registration with the Attorney General. The Pennsylvania rules guide explains who has to register and what the state's guidance leaves unsaid about duct cleaning. The practical steps are short.

• Ask for the registration number. Registered contractors must show it, as PA followed by digits, on their advertisements, estimates and contracts.
• Look it up. Use the Attorney General's contractor search, or call 1-888-520-6680.
• Read registration for what it is. The Attorney General says it is not an endorsement of a contractor's honesty or quality of work, and advises checking references, getting more than one bid and checking for complaints with the Better Business Bureau as well.

What else should you check?

• References. The EPA says to check that other customers were satisfied and had no problems with their heating and cooling system afterwards.
• Complaints. The EPA suggests asking your county or city office of consumer affairs, or the local Better Business Bureau, whether complaints have been lodged against the company.
• Experience with a system like yours. The EPA says to confirm the company has worked on systems like yours and will use procedures that protect you, your pets and your home from contamination.
• Insurance. NADCA advises getting proof that a company is adequately insured.
• Who is in charge of the job. NADCA recommends that the certified person be a full-time employee who oversees all of the company's duct cleaning projects. Ask who that is and whether they will be at your house.
• Equipment. NADCA does not favor truck-mounted vacuums over portable ones. It says both can do the job, but any vacuum that exhausts indoors must be HEPA filtered. The EPA says the same.
• Chemicals. Ask in advance whether the company intends to apply any biocide or sealant. The EPA says not to allow either unless you fully understand the pros and cons.

What should be in writing?

The price and the scope, before work begins. The EPA says to get a written agreement that sets out the total cost and scope of the job and, if the price is hourly, an estimate of the hours or days it will take.

The Federal Trade Commission's general advice on hiring contractors adds four points. Get several written estimates. Do not automatically choose the lowest bidder. Ask for an explanation if the estimates differ a great deal. And never make the final payment until the work is done and you are satisfied with it.

The cost guide sets out what published surveys say a cleaning costs and how to compare quotes line by line. Businesses offering the service are listed on the air duct cleaning directory page.

Sources

1. Should You Have the Air Ducts in Your Home Cleaned?, U.S. Environmental Protection Agency
2. Why Hire a NADCA Member?, National Air Duct Cleaners Association (NADCA)
3. Air Systems Cleaning Specialist (ASCS), National Air Duct Cleaners Association (NADCA)
4. NADCA Releases 2025 Edition of ACR, The NADCA Standard for Assessment, Cleaning and Restoration of HVAC Systems, National Air Duct Cleaners Association (NADCA)
5. Frequently Asked Questions, National Air Duct Cleaners Association (NADCA)
6. FAQs, National Air Duct Cleaners Association (NADCA)
7. Avoid the Scams, National Air Duct Cleaners Association (NADCA)
8. Contractor Licensing, Pennsylvania Department of Labor and Industry
9. Frequently Asked Questions: Home Improvement Contractor Registration, Pennsylvania Office of Attorney General
10. Home Improvement Contractor Verification, Pennsylvania Office of Attorney General
11. Home Improvement Contractor Search, Pennsylvania Office of Attorney General
12. How To Avoid a Home Improvement Scam, Federal Trade Commission