Fast, Reliable Air Quality & Ventilation Across San Lorenzo
Air quality and ventilation work in San Lorenzo homes runs into a problem you won’t find many other places: thousands of nearly identical postwar tract houses built without central ductwork, forced-air systems, or any thought toward modern indoor air management. We’re Stonegate Heating & Air California, and our Air Quality & Ventilation team has spent 16 years figuring out how to route clean, conditioned air through homes that were never designed for it. If you live in the Bohannon-era neighborhoods between Hesperian Boulevard and Lewelling Boulevard, or anywhere in the 94580 zip code, we know the crawl spaces, the attic trusses, and the Title 24 permit path for unincorporated Alameda County. Call (855) 467-1888 for a free estimate. Jason Trent supervises every project personally.
Why Stonegate Heating & Air California Is San Lorenzo’s Preferred Air Quality & Ventilation Company
We’ve got 499 verified reviews averaging 4.7 stars, and plenty of them come from San Lorenzo homeowners who found us after another contractor said their house “couldn’t” get central air quality equipment. Jason Trent is on-site as Field Supervisor, not running things from a Sacramento office. That matters when your tech has to figure out how to thread an ERV through a 14-inch crawl space that hasn’t been touched since 1947.
Our response time to San Lorenzo is typically same-day or next-day. We know the difference between the fog-heavy blocks near the Bay and the slightly warmer inland pockets toward Ashland. That local climate knowledge changes what equipment we recommend. The persistent dampness here corrodes ductwork faster than in drier Sacramento Valley towns. We account for that.
We’ve worked on Via Alamosa, Fargo Avenue, and the streets around San Lorenzo Park. We know which homes have the original cast-iron floor furnaces still running, which have been retrofit with wall heaters, and which have had hasty duct additions that created more airflow problems than they solved.
Our Air Quality & Ventilation Services in San Lorenzo
ERV & HRV System Installation
Energy Recovery Ventilators and Heat Recovery Ventilators are the right answer for San Lorenzo’s tightly sealed retrofits, but installing them in Bohannon homes is genuinely tricky. These houses have no equipment closets, no designed plenum space, and attics that weren’t built to hold the weight of modern air handlers. A typical ERV install in San Lorenzo runs $2,800–$4,500, depending on whether we can use existing attic framing or need to reinforce trusses. We replaced a 70-year-old floor furnace in a client’s home on Via Alamosa with a ductless mini-split and added a whole-house dehumidifier to combat the persistent Bay dampness that had corroded their old ductwork. Our techs had to mount the air handler in the attic, which required reinforcing the trusses to support the added weight. That’s the kind of field problem Jason Trent has solved enough times to anticipate.
Dehumidifier Installation
San Lorenzo’s proximity to the Bay means crawl-space moisture is a constant. We’ve pulled corroded flex duct out of crawl spaces on Hesperian Boulevard that looked like they’d been underwater for years. Whole-house dehumidifiers start around $1,200–$2,400 installed in San Lorenzo, with crawl-space units toward the lower end and integrated HVAC systems higher. For Bohannon homes without central ductwork, we often pair a standalone crawl-space dehumidifier with a ductless mini-split system. That handles the humidity at its source without pretending the house has ductwork it doesn’t.
Ventilation Installation
Modern building codes require mechanical ventilation in ways these 1940s homes never considered. If you’re doing a major retrofit or adding square footage, you’ll likely need to meet Title 24 requirements that trigger on permit pulls in unincorporated San Lorenzo. We design ventilation systems that comply without destroying the character or floor plan of these small stucco homes. Expect $1,800–$3,200 for a code-compliant ventilation install, more if we’re integrating with a full HVAC retrofit.
Air Filtration & UV Air Purifier Systems
For homes that do have some duct infrastructure, we install whole-house filtration and UV purification. A standard media filter cabinet runs $400–$800. UV air purifiers add $600–$1,200. In San Lorenzo’s damp climate, UV systems help control microbial growth on wet coils, a real issue when your system is working hard to dehumidify. We size these carefully. Oversized purifiers in compact plenum spaces create pressure drop problems that reduce airflow and strain whatever blower you’ve got.
Humidifier Installation
San Lorenzo rarely needs humidification. The Bay moisture usually keeps indoor humidity above comfortable levels through winter. We do install humidifiers for specific medical needs or for homes with unusual dryness from wood stove use, but we’ll tell you honestly if it’s unnecessary. That’s $500–$1,200 when it makes sense.
What happens when you call
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A real person answersNo phone trees — you reach a local pro.
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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 Lorenzo
We work on Carrier, Trane, Lennox, Goodman, Rheem, York, Daikin, Bryant, and American Standard. For San Lorenzo’s retrofit market, we often lean on Daikin and Bryant ductless systems that don’t require full duct infrastructure. We stock common parts locally, so you’re not waiting a week for a filter rack or a ventilator motor. Whatever brand you have, or whatever brand your retrofit needs, we’ve got factory training and field experience on it.
Common Air Quality & Ventilation Problems We See in San Lorenzo Homes
- Crawl-space ductwork corrosion. The Bay dampness settles into shallow crawl spaces under Bohannon homes and eats galvanized ductwork from the outside in. We regularly find pinhole leaks and collapsed flex duct that has been dumping conditioned air into dirt for years. Homeowners notice musty smells and high utility bills before they realize the ductwork is gone.
- Inadequate ventilation in sealed retrofits. When San Lorenzo homeowners add insulation, seal windows, and install new siding, they trap indoor air pollutants with nowhere to go. New flooring, paint, and cabinetry off-gas VOCs. Without mechanical ventilation, those chemicals recirculate. In some areas near the Hayward fault zone, radon is an additional concern that tight construction exacerbates.
- Oversized equipment crammed into compact spaces. A standard ERV or air purifier designed for a 2,000-square-foot suburban home won’t fit the mechanical space available in a 1,100-square-foot Bohannon tract house. We’ve seen contractors force the issue with custom ducting that creates turbulence, noise, and pressure imbalances. Right-sizing matters more here than almost anywhere.
- 70-year-old floor furnaces still burning. Original cast-iron floor furnaces in narrow hallways have no filtration, no ventilation, and no humidity control. They heat by convection alone, stirring up dust and pulling air from crawl spaces. The combustion efficiency is poor, and the distribution is worse. We’ve found units on Fargo Avenue still running from 1952.
Pricing for Air Quality & Ventilation in San Lorenzo, CA
Here’s what we typically see in the San Lorenzo market:
- Whole-house media filtration: $400–$800
- UV air purifier (coil-mounted): $600–$1,200
- Whole-house humidifier: $500–$1,200
- Crawl-space or whole-house dehumidifier: $1,200–$2,400
- Mechanical ventilation install (Title 24 compliant): $1,800–$3,200
- ERV/HRV system: $2,800–$4,500
What moves the needle: crawl-space accessibility, whether we need to reinforce attic trusses, electrical run distance, and permit complexity in unincorporated Alameda County. We don’t quote over the phone for ERV or ventilation work without seeing the space. Estimates are free. Call (855) 467-1888 to schedule.
We Also Serve Cities Near San Lorenzo
Our Air Quality & Ventilation crews work throughout the East Bay, including Ashland, San Leandro, Cherryland, and Castro Valley. Each of these cities has different housing stock and different air quality challenges. San Leandro’s hillside homes have different moisture patterns than San Lorenzo’s flat tract grid. Castro Valley’s larger lots and newer construction change the ventilation equation. We adjust our recommendations accordingly.
Serving San Lorenzo, CA — Our Local Coverage Area
We’re based in the San Lorenzo 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 Lorenzo
Yes. Any heating system replacement in unincorporated Alameda County triggers current Title 24 energy code requirements, which typically means adding mechanical ventilation and often duct sealing or insulation that wasn’t required when your floor furnace was installed. Homeowners on Via Alamosa and similar Bohannon streets are often surprised by this. We handle the permit application and specify equipment that meets code without overcomplicating your small home. Call (855) 467-1888 and we’ll walk through exactly what your project requires.
Yes, and it’s often the best solution for San Lorenzo’s damp climate. A standalone crawl-space dehumidifier doesn’t need ductwork and can protect your structure and air quality without a full HVAC retrofit. We size these to your crawl space volume and drainage conditions. Some homes on slab foundations near Lewelling Boulevard don’t have accessible crawl spaces, in which case we look at conditioned-space options. Estimates are free.
A ductless mini-split paired with a crawl-space dehumidifier and standalone room air purifiers is usually the most practical path. ERV integration is possible but requires careful attic or crawl-space routing that adds cost. For many Bohannon homes, we start with source control: sealing the crawl space, dehumidifying, and adding filtration at the point of use. Call us to assess your specific layout.
Floor furnaces have no filtration, draw combustion air from inside the house, and often pull dust and crawl-space contaminants through gaps in the hall flooring. If you smell mustiness when the heat runs, see dust accumulation near the grate, or have uneven heating across your small home, the floor furnace is likely part of the problem. We document this during our free estimate and show you exactly what we’d replace it with.
Yes, specifically for controlling microbial growth on cooling coils and in drain pans, which is a real issue here. UV doesn’t remove particulates, so we usually pair it with a media filter. In San Lorenzo’s moisture-heavy environment, the UV-C wavelength prevents the slime and mold that would otherwise colonize your wet coil every summer. We install Bryant and American Standard UV systems sized to your equipment.
Written by Jason Trent, Owner and Field Supervisor at Stonegate Heating & Air California, serving San Lorenzo and the East Bay since 2008.