Fast, Reliable AC Repair & Installation Across Los Altos
AC repair in Los Altos typically costs $150–$650, while a full installation runs $3,500–$7,500. Most repairs are completed same day, though installations in this market often require additional ductwork that extends the timeline. Call Stonegate Heating & Air California at (855) 467-1888 for a free estimate.
We’ve been driving to Los Altos from our Sacramento base for 16 years, and we’ve learned every quirk of the city’s mid-century housing stock. The ranch homes off Foothill Expressway, the tree-canopied neighborhoods near Edith Avenue, the expanded properties along Magdalena Avenue — we’ve worked on ducts and compressors in all of them. Los Altos sits slightly inland from the Bay, tucked against the Santa Cruz Mountains foothills, which means summer afternoons hit the mid-to-upper 80s°F and occasionally spike past 100°F during heat dome events. That’s just enough to make air conditioning necessary, yet mild enough that most homes built between 1950 and 1975 were never designed for it.
This mismatch between modern expectations and original construction defines nearly every job we do here. Homeowners call us expecting a straightforward AC replacement. What they often get is a conversation about California Title 24 duct-leakage testing, failed inspections, and full duct retrofits. We’re upfront about this because we’ve learned that surprises mid-project erode trust faster than any honest timeline ever could.
Why Stonegate Heating & Air California Is Los Altos’s Preferred AC Repair & Installation Company
Our AC Repair & Installation team has earned 499 verified reviews averaging 4.7 stars across platforms — a volume that only comes from showing up consistently and doing the work correctly. Los Altos customers specifically mention our willingness to explain the full scope before starting, particularly when duct retrofits become necessary.
Owner Jason Trent serves as active Field Supervisor, not a passive figurehead. He’s physically present on Los Altos job sites, which matters when you’re coordinating with general contractors on gut-renovation timelines or navigating Title 24 compliance with city inspectors. A tech who knows the equipment is good. A tech who knows the equipment and has the owner standing next to him is better.
We’re factory-trained or experienced on nine leading brands: Carrier, Trane, Lennox, Goodman, Rheem, York, Daikin, Bryant, and American Standard. Whatever system is currently humming (or rattling) in your Los Altos garage or utility closet, we’ve likely serviced it before. No “we don’t work on that brand” dead ends.
From a single-room mini split to a full commercial system, we handle the full spectrum. Emergency HVAC available when you need it.
Our AC Repair & Installation Services in Los Altos
AC Repair
Summer heat spikes in Los Altos — especially during Bay Area heat dome events — push older capacitors and compressors to failure. We see capacitor failures weekly on original or poorly maintained units. Our AC repair calls in Los Altos run $150–$650 depending on parts and accessibility. Most are same-day. We stock common components for Carrier, Trane, Lennox, and Goodman systems to avoid delays.
AC Installation
This is where Los Altos gets complicated. The city’s dominant housing stock — 1,400–2,200 square foot single-story ranch homes built 1950–1975 — was designed around single-speed gas furnaces with undersized ductwork. Installing modern, efficient AC in these homes almost always triggers California Title 24 requirements. We’ve replaced systems on streets near Foothill Expressway where the original flex duct was literally crumbling in the attic. AC installation in Los Altos starts at $3,500 but frequently reaches $7,500 or beyond once duct retrofitting is included. We explain this at estimate time, not after demolition begins.
AC Replacement
Replacing an existing AC unit in Los Altos sounds simple. It rarely is. The original 1960s flex and sheet-metal ductwork in these ranch homes routinely fails mandatory duct-leakage tests — often leaking 30–40% of airflow into unconditioned attic space. What homeowners expect as a straight equipment swap becomes a full duct replacement. We specialize in managing this scope expansion without losing control of timeline or budget. Our team coordinates directly with general contractors when replacement is part of a larger renovation, which is common in Los Altos’s high-value market.
Refrigerant Recharge
Low refrigerant means a leak, and in Los Altos’s mature housing stock, leaks often trace to corroded line sets or failing Schrader valves on original installations. A refrigerant recharge runs $200–$500 depending on refrigerant type and leak location. We don’t just top off and leave — we pressure-test, locate the source, and explain whether repair or replacement makes more sense given your system’s age.
What happens when you call
- 1
A real person answersNo phone trees — you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
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You approve before work beginsNothing starts until you say go.
Trusted Brands We Service in Los Altos
We maintain active certification or deep field experience on Carrier, Trane, Lennox, Goodman, Rheem, York, Daikin, Bryant, and American Standard. For Los Altos customers, this means no referral shuffle when your system needs attention. We stock common parts locally for Carrier, Trane, and Lennox — the three brands we see most frequently in this market — which keeps turnaround tight when a capacitor blows on a Saturday afternoon in July. Goodman systems are increasingly common in retrofit installations for their value, and we carry those components as well.
Common AC Repair & Installation Problems We See in Los Altos Homes
- Failed Title 24 duct-leakage tests on original 1960s ductwork. The flex and sheet-metal runs in Los Altos ranch homes leak 30–40% of conditioned air into attics. This isn’t a minor efficiency hit — it’s a mandatory repair trigger that converts a simple AC swap into a full duct retrofit.
- Wrong-sized equipment from previous unqualified installers. Homes with non-original additions — common along expanded properties on larger lots — get saddled with oversized or undersized units that short-cycle or can’t cool added square footage. We perform proper Manual J load calculations before specifying any replacement.
- Capacitor failures during summer heat spikes. Older models without regular maintenance are especially vulnerable. We’ve replaced capacitors on 90°F July afternoons across Los Altos, from neighborhoods near the Village to properties backing up to the foothills.
- Wildfire smoke driving filtration upgrades. Los Altos sits squarely in the Bay Area’s smoke transport zone. Since 2017, whole-home MERV-13+ filter installations have become a standard add-on to AC work, not a specialty request.
Pricing for AC Repair & Installation in Los Altos, CA
| Service | Price Range |
|---|---|
| AC Repair | $150–$650 |
| Refrigerant Recharge | $200–$500 |
| AC Installation | $3,500–$7,500 |
These ranges reflect what we’ve billed across Los Altos jobs over 16 years. The wide spread on installation reflects the ductwork reality: a home with recently updated ducts stays near the bottom, while a 1965 ranch with original flex requiring full replacement pushes toward the top. We provide itemized estimates before any work begins. No vague numbers, no mid-project add-ons you didn’t approve. Call (855) 467-1888 for a free estimate — we’ll inspect your attic ductwork and give you the real scope.
We Also Serve Cities Near Los Altos
Our service radius covers Los Altos Hills to the west, Mountain View to the north, Stanford to the northeast, and Sunnyvale to the east. Same owner-supervised standards apply regardless of zip code. Whether you’re in a Los Altos Hills estate with multiple zones or a Sunnyvale townhome with a single mini split, Jason Trent oversees the work personally.
Serving Los Altos, CA — Our Local Coverage Area
We’re based in the Los Altos area and know this community well. Use the map below to see our service coverage — if you’re nearby, we can almost certainly help.
FAQs — AC Repair & Installation in Los Altos
Yes. California Title 24 requires a duct-leakage test whenever HVAC equipment is replaced in Los Altos, and the original 1960s ductwork in most ranch homes fails. We schedule the test as part of our standard installation workflow and handle any necessary remediation. Call (855) 467-1888 to discuss your specific home — estimates are free.
These homes were built with heating-only ductwork sized for gas furnaces, not the airflow demands of modern cooling systems. On a quiet block near Edith Avenue, we serviced a 1965 ranch where the original gas furnace was swapped for a two-zone Carrier heat pump. The duct-leakage test revealed 38% loss, so we replaced the sagging flex ducts with sealed sheet metal and added a MERV-13 filter cabinet for wildfire season. The homeowners were shocked at the scope but grateful for the even cooling and improved air quality. This pattern repeats across 94022, 94023, and 94024.
Rarely. The existing ductwork is almost always too leaky and undersized to pass Title 24 or deliver adequate cooling. We evaluate every home individually, but in 16 years we’ve seen fewer than a handful of original duct systems in Los Altos that could accommodate modern AC without significant modification. Call (855) 467-1888 for an honest assessment — we’ll tell you if you’re the exception.
Carrier and Trane dominate our Los Altos installations for their reliability and parts availability, though Lennox and Goodman are excellent alternatives depending on your efficiency goals and budget. The “best” brand matters less than proper sizing and ductwork integration — a premium unit on failing ducts performs worse than a mid-tier system on sealed, correctly sized runs. We match equipment to your home’s specific load and existing infrastructure.
Typically 3–5 business days for a standard single-story ranch, assuming no general contractor coordination is needed. Projects tied to gut renovations — common in Los Altos’s high-value market — may compress or extend depending on the GC’s schedule. We build timeline contingencies for Title 24 testing and any required re-tests. Call (855) 467-1888 to discuss your project’s specific constraints.
Written by Jason Trent, Owner and Field Supervisor at Stonegate Heating & Air California, serving Los Altos and the greater Bay Area since 2008.