AC installation and replacement in Herndon, VA

Replacement is where the money is and where the mistakes are permanent. A system sized wrong is not a fault you get to call back about — it is one you live with for fifteen years.

Herndon contractors listed under AC Installation & Replacement

These are the businesses we list in Herndon whose own services include this work. We report what each listing says — we do not assess or rank workmanship. Paid members appear first.

Other HVAC contractors in Herndon

Listed for other HVAC work, and not listed for this. That is a gap in what we know about them, not a statement that they will not do it.

What this work covers

• Load calculation and sizing for the actual house
• Matched outdoor condenser and indoor coil
• Line set, electrical disconnect, pad and condensate
• Permit and inspection
• Removal of the old equipment and recovery of its refrigerant

Oversizing is the common error, and it is counter-intuitive: a system with too much capacity cools the air fast, satisfies the thermostat, and shuts off before it has run long enough to pull moisture out of the house. You get a cold, clammy room, short cycling, and a compressor doing far more starts than it was built for. The defence is a load calculation — the industry standard is ACCA's Manual J — rather than reading the size off the label of the unit being removed, which only tells you what somebody guessed last time.

The second error is a half replacement. The outdoor condenser and the indoor coil are engineered as a matched pair and rated as a pair; putting a new condenser against an old, mismatched coil gives you neither the efficiency on the sticker nor, in many cases, the manufacturer's warranty. Ask for the rating of the matched pair, not of the outdoor unit on its own.

Then there is the permit. Replacing a system is normally permitted, inspected work, and which office issues that permit depends on where the house physically sits rather than what the mailing address says: an incorporated town runs its own permitting and inspections, and the county runs the process for everywhere outside those town limits. A quote that is notably cheaper than the others is worth reading closely, because the permit and the inspection are frequently the difference. The inspection is the part that protects you.

Contractor data sourced from public web research and cross-checked against the Virginia DPOR License Lookup where noted — the board's own data is not the official public record and may be stale; verify independently before hiring.