Restaurant · Crescent City
Harbor Street Kitchen — hood replacement
Problem. A 14-foot Type I hood installed in 1998 was under-capturing at the wok range and the building went negative every time the dishwasher ran, pulling flue gas back down the water heater vent.
What we did. Fabricated and installed a new 16-foot stainless hood with a dedicated 3,200 CFM exhaust fan and a tempered make-up air unit set to 85% of exhaust volume. Rebuilt 22 feet of welded stainless duct through the roof and re-flashed the curb.
Result. Capture velocity measured 92 fpm across the cook line, building pressure held within ±0.01 in.wc, and the health and fire inspections both passed on the first walk-through. 11 working days from proposal to sign-off.
Healthcare · Crescent City
Del Norte Family Practice — ERV retrofit
Problem. Persistent winter condensation on exterior glass, stuffy exam rooms by mid-afternoon, and CO₂ logging over 1,400 ppm in the waiting area.
What we did. Installed two RenewAire ERV units with dedicated ducted supply to six exam rooms, added transfer paths, and rebalanced the existing rooftop unit so the waiting room ran slightly positive relative to the corridor.
Result. CO₂ now peaks around 780 ppm, indoor RH sits between 42% and 50% through winter, and window condensation has not returned in three heating seasons.
Multi-family · Fairway Ridge
24-unit apartment ventilation upgrade
Problem. Original 1970s bath fans, most non-functional, with mould complaints in eleven units and a manager fielding the same call every wet season.
What we did. Replaced all 24 fans with humidity-sensing continuous-run units, re-ducted 19 of them to proper roof caps (nine had been terminating in the attic), and sealed penetrations.
Result. Complaint volume dropped to zero across the following winter. Phased over three weeks with two units per day so no tenant lost a bathroom overnight.
Light industrial · Smith River
Seafood processing room — corrosion rebuild
Problem. Galvanised exhaust duct in a wet processing room had corroded through at the seams after six years, dripping onto the floor below the wash-down line.
What we did. Rebuilt the run in 304 stainless with fully welded, liquid-tight seams pitched back to a drain point, and specified a corrosion-rated fan with a coated wheel.
Result. Four years in, annual inspection shows no seam degradation. Cost roughly 30% more than a like-for-like galvanised replacement and will outlast it three times over.
Education · Klamath
Elementary classroom air quality survey
Problem. The district needed documented ventilation rates across eight classrooms for a funding application, with no drawings available.
What we did. Surveyed and measured every terminal, mapped the existing distribution, logged CO₂ across a full school day, and produced a report with prioritised remediation costed in three tiers.
Result. Application submitted on schedule; tier one works completed the following summer break.
Residential · Gasquet
1948 cottage — whole-home ventilation
Problem. A deep-energy retrofit had tightened the envelope beautifully and left the house with almost no fresh air path. Cooking smells lingered for hours.
What we did. Designed a compact ducted HRV around the existing crawlspace, using low-profile oval duct to clear a 14-inch joist bay, with a boost switch in the kitchen.
Result. 0.35 air changes per hour continuous, verified by tracer measurement, at an added heating cost the owner estimates at under $9 a month.