Heating and air conditioning repair in Detroit
Our guide to heating and air conditioning repair covers how the job works. Below: the Detroit numbers a HVAC contractor looks at, with sources.
What the housing in Detroit tells a provider
1947 is the median construction year for homes in Detroit (Census ACS). By median year built, homes here are older than in 49 of the 56 other cities we cover. Older homes here often have ducts and venting that were sized for a different system.
Source: Census ACS
Source: Census ACS
Roughly 50 in every 100 occupied homes in Detroit are owner-occupied. That is 129,895 of 257,998 households. Of the 56 other cities in this network, 30 have a lower share of owner-occupied homes. Owners usually decide on a replacement; renters should start with the landlord or property manager.
Source: Census ACS
Source: Census ACS
In Detroit, about 80% of occupied homes heat with utility gas, more than any other fuel. Other fuels: electricity 17%, bottled or tank gas 1%, fuel oil or kerosene under 1%. Homes on that fuel need a contractor licensed and equipped for it.
Source: Census ACS
Source: Census ACS
Heating and cooling load in Detroit
Cooling load in Detroit comes to roughly 803 cooling degree days in a normal year (NOAA 1991-2020 normals). Measured at the Dearborn #2 (MI) station. Of the 56 other cities in this network, 11 have a lower cooling load. That cooling load is what an air conditioner or heat pump has to keep up with on the long summer afternoons.
Source: NOAA normals
Source: NOAA normals
Detroit averages about 6,138 heating degree days a year, the NOAA measure of winter heating load. Measured at the Dearborn #2 (MI) station. The heating load here is higher than in 50 of the 56 other cities we cover. Winters at that level put most of the year's wear on the heating side.
Source: NOAA normals
Source: NOAA normals
Lows at or below 32 F come on roughly 125 days a year around Detroit. Of the 52 other cities in this network, 45 have a lower number of freezing days.
Source: NOAA normals
Source: NOAA normals
A normal year brings about 17 days of 90 F or hotter near Detroit (NOAA normals). The number of 90 F days here is higher than in 14 of the 54 other cities we cover.
Source: NOAA normals
Source: NOAA normals
Seasons and risk in Detroit
On heat wave risk, FEMA's National Risk Index puts Wayne County, MI at relatively high. 30 of the 55 other cities we cover sit in counties with the same heat wave rating. Heat waves are when an older air conditioner is most likely to fail, so a pre-season check pays off.
Source: FEMA risk index
Source: FEMA risk index
The cold wave risk for Wayne County, MI is rated very high in FEMA's National Risk Index. 16 of the 53 other cities we cover sit in counties with the same cold wave rating. A cold wave also stresses pipes and venting near the furnace, worth a look during a tune-up.
Source: FEMA risk index
Source: FEMA risk index
In Michigan, HVAC contractors are licensed by the Michigan LARA Bureau of Construction Codes, Mechanical; status can be checked on the agency's official lookup page.
Source: Michigan LARA Bureau of Construction Codes · Michigan LARA Bureau of Construction Codes · Michigan page linking to the lookup
Source: Michigan LARA Bureau of Construction Codes · Michigan LARA Bureau of Construction Codes · Michigan page linking to the lookup
Sources, checked October 2026
- U.S. Census Bureau, ACS 2024 5-year, profile 16000US2622000
- NOAA NCEI U.S. Climate Normals 1991-2020, station USC00202016
- FEMA National Risk Index (December 2025), Wayne County, MI
- Michigan LARA Bureau of Construction Codes, Mechanical (Michigan)
- Michigan LARA Bureau of Construction Codes, Mechanical license information
- Michigan page linking to the lookup
Local offices and rules in Detroit
BSEED reviews building, mechanical and plumbing permits against the current State of Michigan Building, Mechanical and Plumbing Codes rather than a separate city code.
Source: detroitmi.gov. Checked October 2026.
Source: detroitmi.gov. Checked October 2026.
In Detroit a separate mechanical trade permit is required for changes to mechanical systems, including replacement of system components, and the application lists a City of Detroit licensed Mechanical Contractor; processing takes about one day.
Source: detroitmi.gov. Checked October 2026.
Source: detroitmi.gov. Checked October 2026.
DTE pays residential natural gas customers furnace replacement rebates that step down from 98% AFUE or higher to 96-97% AFUE and then 95% AFUE, submitted by the installing contractor; funds are first-come, first-served, and a bonus applies to installs from Oct. 1 to Dec. 15, 2026.
Source: www.dteenergy.com. Checked October 2026.
Source: www.dteenergy.com. Checked October 2026.
DTE Electric, headquartered in Detroit, generates and distributes electricity to about 2.3 million customers in southeastern Michigan, including the city.
Source: www.dteenergy.com. Checked October 2026.
Source: www.dteenergy.com. Checked October 2026.
Natural gas in Detroit is delivered by DTE Gas, which serves roughly 1.4 million Michigan customers.
Source: www.dteenergy.com. Checked October 2026.
Source: www.dteenergy.com. Checked October 2026.
If you smell gas, leave the house and call your gas utility from outside. Keep a working carbon monoxide alarm near the bedrooms, and do not open a furnace cabinet that is running.
Common jobs
