HVAC Installation in Gaithersburg, MD
A new system here will heat from October through April and cool from June through September every year. Tell us about the house, and a licensed contractor who covers Montgomery County will get in touch.
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What a system in Gaithersburg has to handle
Your furnace or your air conditioner is working eleven months out of the year here. Heat runs October through April, seven months, on winter nights that average 27°F. Cooling picks up June through September, with afternoons averaging 85°F. There is not much of a season where the system just sits.
Just over half the homes in this area heat with gas, and any new furnace has to meet the federal efficiency minimum. But a unit sized wrong for your house will run harder than it should no matter what its rating says, and with this many months of use, that difference shows up fast. Power is worth planning around too. Maryland saw 11% of households lose power for at least a day in 2024, and the region has logged 23 winter storms and 443 damaging wind events over the past ten years. A system installed to hold up through that is worth doing right the first time.
- 7 months
- October through April, your system heats
- 4 months
- June through September, it cools
- 27°F
- the average winter night it heats against
- 85°F
- the average summer afternoon it cools against
NOAA nClimDiv, 1991–2020 normals
Maryland requires HVAC contractors to hold a state license.
Maryland licenses HVAC contractors through the Board of Heating, Ventilation, Air Conditioning, and Refrigeration Contractors. That license belongs to the contractor, not to this particular job, so it tells you this business met the state's standard to do HVAC work in general, not that anyone signed off on your installation.
For a new heating and cooling system, the license backs the contractor doing the work, but the installation itself gets checked separately. In most cities and counties, putting in a new furnace or air conditioner needs a permit from the local building office and an inspection once the work is done. That inspection is what confirms the installation itself was done right. The license and the permit cover two different things, and this job needs both.
Sources: Maryland General Assembly · Maryland Department of Labor
- When should I replace my HVAC system?
- Once your furnace or air conditioner is breaking down more than once a season, or a contractor tells you the heat exchanger or coil has failed, replacement makes more sense than another repair. Age matters too. A furnace or air conditioner working hard for 11 months of the year here, heat from October through April, cooling from June through September, wears faster than one running in a milder climate. If your system is old and you're already calling for repairs each winter or summer, get a contractor out to look at it before it fails on the coldest or hottest day.
- Should I replace my furnace and air conditioner at the same time?
- If both are old, replacing them together usually makes sense, especially since a furnace and air conditioner often share a coil or air handler that has to match the new equipment. A mismatched system, an old furnace paired with a new coil sized for a different air conditioner, can run poorly or wear out early. If only one has failed and the other is newer, a contractor can tell you whether they'll work together or whether waiting causes problems down the line.
- What happens during an HVAC installation?
- A contractor removes the old furnace or air conditioner, sets the new equipment, and connects it to your ductwork, gas line or electrical circuit, and the refrigerant lines. Once it's running, they test it, check refrigerant charge, and confirm the thermostat and airflow are working correctly. In most places, including here, this job needs a permit from the local building office and an inspection when the work is done. That inspection is there to confirm the installation was done to code, so don't skip it even if a contractor offers to.