Fast, Reliable Air Quality & Ventilation Across San Rafael
Air quality and ventilation installation in San Rafael typically runs $3,500–$7,500 for ERV/HRV systems, with most homes in the Terra Linda basin and western hills needing custom sizing to match Marin County’s sharp microclimates. We’re Stonegate Heating & Air California, and our Air Quality & Ventilation team makes the drive to San Rafael regularly from our Sacramento base, usually arriving same-day for scheduled work. After 16 years and nearly 500 reviews, we know that San Rafael’s mix of 1960s ranch homes, pre-war bungalows, and hillside properties with no existing ductwork demands a contractor who shows up prepared for anything, not someone who makes two trips because they didn’t account for your home’s actual conditions.
Call (855) 467-1888 for a free estimate. Jason Trent, our owner and Field Supervisor, personally reviews San Rafael job specs before we head out.
Why Stonegate Heating & Air California Is San Rafael’s Preferred Air Quality & Ventilation Company
We’ve built our reputation in the Bay Area on showing up with the right equipment and the right experience. In San Rafael, that means understanding the difference between a Terra Linda ranch built in 1968 with original flex duct crumbling in a 130°F attic, and a 1920s bungalow in the Canal district with zero ductwork and a wall heater. Our 499 verified reviews at 4.7 stars reflect jobs where we got these details right, not where we showed up with a one-size-fits-all approach.
Jason Trent doesn’t just own Stonegate, he serves as Field Supervisor on jobs. When we quote an ERV system for a San Rafael home, he’s reviewed the attic conditions, the HERS testing requirements Marin County mandates, and whether your microclimate justifies full ventilation or something more targeted. That’s the difference between a contractor who sends whichever tech is available, and one where company leadership is physically accountable on your job site.
We service nine major HVAC brands, Carrier, Trane, Lennox, Goodman, Rheem, York, Daikin, Bryant, and American Standard. For San Rafael customers, this matters because many 1970s-era systems still running in Terra Linda are legacy brands that newer contractors won’t touch. Whatever equipment you have, we’ve likely worked on it before.
Our Air Quality & Ventilation Services in San Rafael
ERV & HRV System Installation
San Rafael’s inland valley position creates one of the steepest microclimatic gradients in Marin County. Terra Linda flatlands and east-facing hillsides see genuine summer heat loads hitting 95–100°F, while western hillside addresses in the same ZIP may need cooling only a handful of days per year. This means ERV and HRV sizing can’t rely on county-wide averages. We size by neighborhood.
In Terra Linda specifically, the 1960s-era ranch homes with original flex ductwork often suffer from collapsed or separated ducts in attics that exceed 130°F during Diablo wind events, causing newly installed systems to lose 30–40% capacity to leakage before they even run. We recently retrofitted an ERV system for a homeowner in the Terra Linda flatlands (94903) whose 1972 ranch had original sheet-metal ducts never designed for cooling. After sealing over 40% leakage in the attic flex, we installed a Bryant ERV to control humidity and bring in fresh air during the 100°F summer peaks, ensuring the new split-system AC could actually keep the home comfortable.
Marin County requires HERS duct leakage testing on replacements. We build this into our quotes upfront, not as a surprise add-on.
Ventilation Installation
Homes on gravity or floor furnaces in the Canal area and older downtown neighborhoods have zero ductwork. Any ventilation upgrade here requires a full install from scratch. We’ve seen contractors skip the HERS leakage test on these jobs and fail final inspection, costing homeowners weeks and extra fees. We don’t quote ventilation work in 94901 without accounting for the duct infrastructure your property actually has, or doesn’t have.
Dehumidifier Installation
Western hillside addresses in 94901 see fog-shielded conditions that keep humidity elevated through spring and early summer, while Terra Linda’s exposed flatlands bake dry. An oversized dehumidifier in a hillside home short-cycles and wastes energy; an undersized unit in a flatlands home with duct leakage won’t keep up. We specify dehumidifiers matched to your San Rafael microclimate, not your ZIP code.
Air Filtration & UV Air Purifiers
San Rafael’s oak and bay laurel pollen loads hit hard in Terra Linda’s exposed valley floor. A UV air purifier installed in your ductwork neutralizes biological contaminants before they circulate, but only if your ducts are intact enough to carry the treated air where it needs to go. We assess duct condition first, then specify filtration.
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.
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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 San Rafael
We maintain factory-trained or equivalent experience on nine leading brands: Carrier, Trane, Lennox, Goodman, Rheem, York, Daikin, Bryant, and American Standard. For San Rafael customers, this eliminates the “we don’t service that brand” dead end. We stock common parts for Carrier, Trane, and Lennox systems specifically, which cuts turnaround when your ventilation system needs component replacement. From a single-room mini split to a full commercial system, one team handles it.
Common Air Quality & Ventilation Problems We See in San Rafael Homes
- Collapsed flex duct in Terra Linda attics. Original 1960s flex duct in Terra Linda attics collapses or separates during 130°F attic temps, wasting 30–40% of new system capacity before it reaches living spaces. We find this on nearly every ranch home inspection in 94903.
- Zero duct infrastructure in Canal-area homes. Homes on gravity or floor furnaces in the Canal area have zero ductwork, so any air quality upgrade requires a full duct install from scratch, tripping up contractors who skip the HERS leakage test.
- Microclimate mismatches on hillside properties. Western hillside addresses in 94901 see only a handful of hot days per year, so oversized ERV/HRV or dehumidifiers run inefficiently or short-cycle, while nearby flatlands need full cooling loads.
- Failed inspections from untested duct replacements. Marin County’s permit office requires duct leakage testing (HERS) on replacements. Skipping this before quoting is a common and costly mistake we see from out-of-area contractors unfamiliar with local code.
Pricing for Air Quality & Ventilation in San Rafael, CA
Here’s what San Rafael homeowners typically invest:
| Service | Price Range |
|---|---|
| ERV/HRV Installation | $3,500–$7,500 |
| Ventilation Install (with ductwork) | $3,500–$7,500 |
| Dehumidifier Install | $1,200–$3,500 |
| UV Air Purifier | $800–$2,000 |
| Whole-Home Air Filtration | $600–$1,800 |
| Tune-Up / Assessment | $80–$200 |
What moves your price: whether your San Rafael home has existing ductwork or needs full installation, whether Marin County HERS testing reveals leakage requiring repair, and whether your property sits in Terra Linda’s heat-exposed flatlands or the cooler western hills. Homes with original 1960s ductwork almost always need sealing or replacement before new ventilation equipment performs as rated. We quote this upfront, not after we’ve started.
Call (855) 467-1888 for a free estimate. We’ll assess your duct condition, your microclimate needs, and your existing equipment before recommending anything.
We Also Serve Cities Near San Rafael
Our Air Quality & Ventilation coverage extends throughout central Marin. We regularly work in San Anselmo, Fairfax, Lucas Valley-Marinwood, and Kentfield, where many of the same microclimate and housing-stock challenges apply. If you’re unsure whether your address falls in our service radius, call and we’ll confirm.
Serving San Rafael, CA — Our Local Coverage Area
We’re based in the San Rafael 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 — Air Quality & Ventilation in San Rafael
Yes. Any duct replacement or new ventilation installation in Marin County requires HERS testing, and 1960s Terra Linda ranches with original flex duct almost always fail initial leakage standards. We build the test and any necessary sealing into our quotes so you don’t face a failed inspection. Call (855) 467-1888 and we’ll walk through what your specific property needs.
You’re likely losing 30–40% of your conditioned air to duct leakage in an attic that exceeds 130°F during Diablo wind events, or your home lacks mechanical ventilation entirely. In Terra Linda especially, original 1960s ductwork was never designed to handle modern cooling loads. We find and seal the leaks, then size ventilation equipment to your actual home, not your square footage alone. Call (855) 467-1888 for a duct assessment.
Yes, for western hillside homes in 94901 where fog-shielded conditions keep indoor humidity elevated and cool. A properly sized humidifier balances moisture levels that prevent dry air symptoms without encouraging mold. We don’t recommend the same humidifier spec for Terra Linda’s drier flatlands. Call (855) 467-1888 and we’ll size for your microclimate.
Yes, but only if your ductwork is intact enough to distribute treated air. UV purifiers neutralize biological contaminants including pollen, mold spores, and bacteria at the coil or air handler. In Terra Linda homes with collapsed flex duct, we seal first, then install. Call (855) 467-1888 for an assessment of whether your ducts can support effective UV treatment.
For most San Rafael workshops, an ERV is the better choice because it transfers both heat and moisture, handling the sharp swings between Terra Linda’s dry summer heat and fog-season humidity. An HRV transfers only heat and can over-dry in certain conditions. We size by your workshop’s use, insulation, and whether it’s heated year-round. Call (855) 467-1888 and Jason Trent will review your specific setup.
Written by Jason Trent, Owner and Field Supervisor at Stonegate Heating & Air California, serving San Rafael and the greater Bay Area since 2008.