13 AC Installation Contractors in Longmont, CO
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Top-Rated AC Installation Contractors in Longmont
M and M Heating, Cooling, Plumbing and Electrical
“Every reviewer in the sampled set awarded 5 stars, and none of those reviews expressed concerns about pricing or callbacks. Karl Moeller explicitly noted that…”
Welzig Heating, Air, Plumbing & Electric
“All six visible reviews award 5 stars, with three reviewers specifically naming technicians Zach and James while describing repair outcomes. Four reviewers…”
All AC Installation Contractors (13 total)
Blue Valley Heating & Cooling
“1181 reviewers maintain a 4.8-star average, with multiple five-star reviews praising specific technicians by…”
TNT Home Services - Longmont
“Among 864 reviews, the 5-star feedback consistently highlights specific technicians like Craig, Adam, and…”
KJ Thomas Mechanical
“All 252 reviews carry 5-star ratings, with customers consistently praising honest estimates, on-time…”
Colorado's Finest Heating and Air Conditioning
“215 reviews yield a 4.9 average rating, with Jordan mentioned specifically across multiple five-star reviews…”
Carroll Mechanical Services
“All 77 reviewers awarded 4 or 5 stars, with customers specifically praising technician knowledge, transparent…”
Prime Performance Mechanical
“5 of 6 displayed reviews carry 5-star ratings, with owners consistently noting the founder's hands-on…”
Circulating Air Inc
“All five detailed reviews award perfect five-star ratings, with four specifically praising technician…”
Highland Heating & Air, Inc.
“5 of 7 reviewers assign 5-star ratings, with Chris, Scott, Jack, and Ashley named as individual technicians.…”
Woelfel Heating & Air
“Five of seven detailed reviews award 5 stars, with technicians named in each top rating. Positive feedback…”
AC Installation Costs in Longmont
New central AC installation costs in Longmont, by system type and brand.
| Service | Low | Average | High |
|---|---|---|---|
Window unit | $168 | $392 | $784 |
Ductless mini-split (single zone) | $2,240 | $5,040 | $8,960 |
Central AC replacement (existing ducts) | $3,920 | $7,280 | $13,440 |
Central AC new install (with ductwork) | $7,840 | $13,440 | $22,400 |
Carrier (residential) | $4,256 | $6,944 | $11,760 |
Trane (residential) | $5,600 | $9,856 | $15,232 |
Lennox (residential) | $3,920 | $7,280 | $13,440 |
Rheem (residential) | $3,584 | $6,160 | $10,080 |
Prices reflect continental metro averages compiled from published industry cost guides, contractor surveys, and regional labor data. Last updated: April 2026.
AC Installation in Longmont, CO: What to Expect
Longmont sits on Colorado’s northern Front Range where high-altitude summers push daytime highs into the upper 80s and winters dip into the teens. Thin air at roughly 5,000 feet causes most air conditioners to derate 10–15% versus sea-level specs, and that quickens the consequences of improper sizing. With six contractors serving the area and an average 4.8 rating across 2,606 reviews, ac-installation Longmont is a focused, competitive market.
The dataset didn’t provide a usable cost range for top line items, so expect pricing to hinge on equipment size, SEER rating, ductwork condition and permit needs; unit capacity must be increased slightly to offset altitude derating. Colorado lacks a statewide HVAC license, so confirm local municipality licensing and look for proof of insurance, permit experience and manufacturer-authorized installer status before signing a contract.
Customer highlight entries were not supplied, so patterns in individual technician names or comments aren’t available. Still, review summaries show a market where four of six firms advertise 24/7 service—availability matters. Prioritize contractors who document load calculations, show prior installations nearby, offer clear warranties and can reconcile sizing with the area’s heating-dominant load profile.