THOMAS D. STERN AIR EXPERTS INC

Permits are pulled before work begins and then inspected by the county. A contractor who files them is working inside a system with an inspector in it, which is what unpermitted work avoids.

What the permits show

Of the permits we observed, 96% are HVAC work.

HVAC 25

Plumbing 1

Typical job observed: 60,000 BTU.

Each county's permit system holds only their own records, so the combined view above exists nowhere else.

Recent work

• Interior work
  August 2026 · Anne Arundel County

  duct work for one bathroom exhaust vent and one powder room exhaust vent.

• HVAC install
  August 2026 · Anne Arundel County

  Install a new exhaust Duct for dryer.

• Interior install
  August 2026 · Howard County

  Install one new exhaust duct to exterior for bathroom.

• HVAC install 12,000 BTU
  July 2026 · Howard County

  Install single zone 12,000 Btu Mitsubishi mini split . model MMSZWX12NL indoor MUZWX12NL outdoor.

• Heat pump install 18,000 BTU
  July 2026 · Anne Arundel County

  Install 18,000 BTU Air temp mini split heat pump.

• Basement finishing
  May 2026 · Anne Arundel County

  Install 1,6 inch supply duct and 1, 6 inch return duct to basement bedroom.

• Heat pump install
  March 2026 · Howard County

  Separating main level from top level of home installing new 2.5 ton hybrid heat pump system for the top level of home t…

• Kitchen renovation
  January 2026 · Howard County

  Venting the kitchen range hood to the back of the house. -Venting the dryer into a metal wall pan and terminating the v…

• Furnace replacement 80,000 BTU
  June 2025 · Howard County

  Replace (1) 80,000 btu gas furnace with a 80,000 btu gas furnace. Furnace is located in the basement.

• Furnace replacement 60,000 BTU
  April 2025 · Howard County

  Replace 60,000Btu 92% gas furnace with a Bryant 60,000 btu 92% gas furnace. Model #912SE36060M14.

Licensing

• Maryland HVACR Contractor Issued by Maryland Board of Heating, Ventilation, Air Conditioning and Refrigeration. Verify
• Natural Gas Fitter Issued by Maryland Board of Plumbing. Verify

Towns we observed them working in

We hold permit records for Anne Arundel County, Baltimore City, Baltimore County, Carroll County, Frederick County, Howard County, Prince George's County, and Washington DC. Work anywhere else is not missing from this contractor's record, it is outside what we cover.

Permits by year

Our records for this contractor's counties begin August 2021. Years before that are not shown because we hold nothing for them, not because nothing happened.

What this page is, and is not

• Howard County: 21 permits observed, from records beginning August 2021.
• Anne Arundel County: 5 permits observed, from records beginning December 2025.

This page shows permits we observed in county records. Our observation is not complete: work done before those dates, in counties we do not cover, or on filings that name no contractor does not appear here. A contractor's real work is almost always greater than what we observed, and absence of a permit on this page does not mean the work was not done or not permitted. We currently hold records for Anne Arundel County, Baltimore City, Baltimore County, Carroll County, Frederick County, Howard County, Prince George's County, and Washington DC; see permit coverage for what that includes.

Common questions

Does a permit record mean this contractor is licensed?

County permit records list THOMAS D. STERN AIR EXPERTS INC under Maryland HVACR Contractor, Natural Gas Fitter. Check current standing with the issuing body before hiring.

Why do some contractors show more permits than others?

Counties began publishing at different times and describe contractors differently, so the number reflects what we observed as much as what the contractor did. It is not a ranking.

What should I still ask for?

Proof of insurance, a written contract, and the license number for the trade being performed. A permit record is a starting point, not a substitute for either.

Other HVAC contractors in Howard County