9 Best Indoor Air Quality Companies in Seattle, WA (2026)
Seattle's long rainy season and daily traffic increase indoor mold risk and particulate pollutants in homes. Homeowners in Capitol Hill, Ballard, Queen Anne, and Fremont often seek the best indoor air quality hvac companies in seattle wa for mold testing and ventilation upgrades. Duct cleaning and filtration installs are also common.
Quick Picks
Awards based on the same publicly available signals as the Vouched Score, including provider-stated certifications and dealer status. Not independently verified.
How these 9 local Indoor Air Quality pros differ on emergency response and warranties
| # | Provider | Score | Years | Best for | |
|---|---|---|---|---|---|
| 1 | GGreenwood Heating and Home Services | 88 | 4.9 (4,725+) | 105+ | ★ Highest Vouched Score |
Editorial: Ventilation-focused installations, including ERV/HRV, are listed on Greenwood's site. Strengths:
Reviewers praise:
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| 2 | EEvergreen Home Heating and Energy | 84 | 4.8 (1,000+) | 51+ | |
Editorial: Ventilation specialization leads the offering, with ERV/HRV ventilation listed on the site. Mitsubishi dealer status appears for heat pump and HVAC installs. Evergreen notes financing options, including an 18-month special financing offer. The company advertises flat-rate pricing and free estimates for Seattle projects. Evergreen ties to Seattle rebates and local heat-pump incentives supporting electrification. Strengths:
Reviewers praise:
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| 3 | BBrennan Heating, Air Conditioning, & Electric | 82 | 4.5 (2,240+) | 39+ | Whole-Home Air PurificationHumidity Control |
Editorial: Ventilation work highlights ERV/HRV installations, per their site. Aeroseal duct sealing is listed as a certified service. Humidifier and whole-house humidification systems appear among their IAQ offerings. Brennan has served Western Washington since 1987, tying them to Seattle's damp, mold-prone climate. Review excerpts praise punctual crews and thorough explanations of work. Strengths:
Reviewers praise:
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| 4 | GGlendale Heating & Air Conditioning | 82 | 4.8 (705+) | 88+ | |
Editorial: Air purification is a named specialization on Glendale's site with whole-home options noted. Glendale Heating notes flat-rate quotes and same-week appointment availability. Glendale Heating has operated from the Seattle area since 1938, listed as 85+ years in business. Their site emphasizes humidifier and dehumidifier installs for Seattle's mild, humid maritime climate. Strengths:
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| 5 | GGo Green Heating AC & Electric | 72 | 4.8 (225+) | 10+ | |
Editorial: ERV/HRV ventilation installations are listed among Go Green Heating AC & Electric's IAQ offerings. Strengths:
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| 6 | PProgressive Comfort Solutions | 71 | 4.9 (155+) | 16+ | |
Editorial: Ventilation-focused ERV/HRV installations are listed as a specialty on their site. Strengths:
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| 7 | MMark’s Mini Splits | 66 | 5.0 (45+) | ||
Editorial: Ventilation-focused installs emphasize ERV/HRV systems and mechanical fresh-air solutions. Mark’s Mini Splits states free estimates are available. The company highlights a two-hour service radius from Seattle. The site notes a no-upselling policy during estimates or installs. The business references Seattle's mild, damp climate when sizing systems. Strengths:
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| 8 | MMake It Wright HVAC | 65 | 5.0 (35+) | ||
Editorial: Ventilation installs focus on ERV/HRV systems noted on their site. Make It Wright lists cold-climate heat pump expertise. The company advertises financing options for larger projects. Seattle's damp climate increases ventilation importance for moisture control and odor reduction. Strengths:
Reviewers praise:
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| 9 | OOne Hour Heating & Air Conditioning | 63 | 5.0 (30+) | ||
Editorial: Air purification work is called out on the Central Seattle location page. The Central Seattle office lists ERV/HRV ventilation capability. One Hour Heating & Air Conditioning advertises financing options for larger IAQ installs. The company notes humidity control and whole-home dehumidifiers on its service list. Local Seattle demand favors ventilation upgrades for damp, mild Pacific Northwest homes. Strengths:
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Typical Indoor Air Quality costs in Seattle, WA (2026)
Last updated
Estimated ranges for Seattle, WA. Actual cost varies with home size, equipment, and scope — always request a written quote for your job.
| Service | Typical range |
|---|---|
| Whole-house media/electronic air cleaner (installed) | $600–$1,800 |
| Whole-house HEPA air purifier (bypass, installed) | $1,800–$4,800 |
| UV-C germicidal lamp (in-duct, installed) | $360–$1,450 |
| Whole-house humidifier (installed) | $480–$1,800 |
| Whole-house dehumidifier (ducted, installed) | $1,550–$3,350 |
| ERV/HRV ventilator (retrofit, installed) | $1,550–$3,600 |
| High-MERV media filter cabinet (MERV 13+, installed) | $180–$840 |
| IAQ assessment / air-quality testing | $240–$720 |
Nearby Washington indoor air quality pricing: Auburn · Bellevue · Bellingham
See broader context: Indoor Air Quality pricing in Washington · Indoor Air Quality pricing nationwide
What measures determined these Seattle Indoor Air Quality picks?
This guide evaluated 9 Seattle indoor air quality providers on review scores, emergency availability, equipment offerings, and claimed services. Review counts and ratings come from Google Maps data, while provider-stated warranties, pricing, and certifications were checked against company websites and BBB/registry notes and Washington State L&I and SDCI records.
- Greenwood Heating and Home Services shows 4.9/5.0 across 4,729 Google reviews, per Google Maps data.
- Brennan Heating, Air Conditioning, & Electric lists Aeroseal certification and free estimates on its website.
- Evergreen Home Heating and Energy advertises flat-rate pricing and a Mitsubishi Authorized Dealer status.
- Glendale Heating & Air Conditioning notes whole-house humidifier and dehumidifier installations on its service pages.
- Make It Wright HVAC and Mark’s Mini Splits state they offer free estimates; Make It Wright notes cold-climate heat-pump installs.
Ratings and review counts are drawn from Google Maps data, with provider claims cross-checked against company sites and BBB records where available.
How do I choose an Indoor Air Quality Company in Seattle?
- Verify licensing and complaints per state records or BBB.
- Compare Google review counts and ratings for recent performance.
- Confirm equipment options like whole-house humidifiers or dehumidifiers.
- Request written pricing and any advertised warranty details.
- Check emergency service hours and stated response windows.
4 Seattle indoor-air headaches that send homeowners calling pros
Most common indoor air problems in Seattle stem from a long rainy season and frequent traffic, which raise indoor humidity and particulate levels. Closed-up homes during wet months trap moisture, molds, and vehicle-related fine particles, so homeowners often notice persistent damp odors, visible mold, and stale air.
- Mold and musty smells: Seattle's October–April rainy season raises indoor humidity and wall cavity moisture, promoting visible mold and hidden rot that often requires professional remediation.
- Traffic-related fine particles: Daily traffic near busy corridors increases PM2.5 and soot infiltration in Seattle homes, causing dusty surfaces and exacerbating asthma and allergy symptoms.
- High indoor humidity and dust-mite growth: Prolonged damp months keep indoor relative humidity elevated in Seattle, which encourages dust-mite populations and worsens allergy symptoms without dehumidification or ventilation fixes.
- Persistent condensation and window fogging: Frequent rain and closed windows in Seattle trap warm, moist indoor air against cold glass, causing condensation that can lead to trim rot and indoor-air quality decline.
How Seattle’s neighborhoods, rainy season, and contractor rules shape IAQ decisions
Seattle's long rainy season and frequent traffic increase indoor humidity and fine particles, raising demand for indoor air quality services in Seattle, Washington. Homeowners need ventilation fixes, whole-house dehumidification, and targeted filtration to control mold, dust-mite growth, and PM2.5 during wet months.
Rainy season October–April raises indoor relative humidity across Capitol Hill, Ballard, and Queen Anne.
Higher humidity accelerates mold growth and trim rot in older Craftsman and bungalow homes.
Evaluated providers commonly install whole-house dehumidifiers and supply balanced ventilation to stop moisture cycles.
Traffic corridors near Downtown and Capitol Hill raise PM2.5, requiring higher-MERV filtration and targeted air cleaners.
Many evaluated technicians offer emergency response and on-demand IAQ testing during persistent damp episodes.
Contractor registration and L&I licensing apply to ventilation and duct work in Seattle.
How quickly can a Seattle Indoor Air Quality contractor respond—and what licensing matters?
- How do I get a quote from these indoor air quality companies?
- Submit one request on this page and we send it to the vetted indoor air quality pros in Seattle, WA listed here. They send quotes back — no obligation.
- How much does indoor air quality service cost in Seattle, WA?
- Whole-house HEPA air purifier typically runs $1,800–$4,800, and UV-C germicidal lamp runs $360–$1,450 in Seattle, Washington. See the Indoor Air Quality pricing table on this page for the full per-service breakdown.
- Do Seattle IAQ contractors need Washington State Department of Labor & Industries licensing and city contractor registration?
- Yes. Washington State L&I licenses trades and Seattle requires contractor registration. Permits and registration depend on the work scope, such as duct modifications or mechanical ventilation installs. Always ask technicians to cite their L&I number and show registration before work begins.
- Is a permit from Seattle Department of Construction and Inspections (SDCI) required for ERV or HRV installation?
- Often, yes. SDCI issues permits for mechanical ventilation systems when work alters ducts or mechanical systems. Contractors should confirm permit needs with SDCI and include permit pulls in written estimates.
- When is the busiest season for IAQ contractors in Seattle, and how does that affect scheduling a whole-house dehumidifier install?
- Rainy season October–April is busiest for moisture control work in Seattle. Book consultations early in autumn to avoid multi-week waits. Prioritize availability windows in Capitol Hill or Queen Anne where humid basements are common.
- How do seasonal PM2.5 spikes from traffic affect filter upgrades in Ballard and Downtown?
- Traffic-related PM2.5 raises demand for higher-MERV filters during wet, low-dispersion conditions. Homeowners in Ballard and Downtown often upgrade media filters or add portable cleaners during extended wet spells to reduce indoor particulates.
- What factors most affect IAQ service pricing in Seattle?
- Key factors include scope of work, permit requirements, home age, access to duct runs, and peak-season demand during October–April. Complex moisture remediation or SDCI-permitted mechanical changes raise labor and permit time, not just material cost.
- How can a homeowner verify an IAQ contractor’s experience with high-efficiency filtration and air purifier installs?
- Look for documented job photos, model numbers of installed units, and customer reviews mentioning similar installs. Ask for references from Ballard or Greenwood projects and for test results showing pre- and post-install particulate reduction.
- Do UV-C light installations for microbial control require special licensing or permits in Seattle?
- Installing UV-C within HVAC systems usually falls under mechanical and electrical work that requires licensed tradespeople. Contractors should hold appropriate L&I credentials and follow manufacturer safety guidelines for UV-C placement.
- How quickly can contractors typically respond to urgent moisture-related IAQ problems during a wet spell?
- Many evaluated technicians offer emergency assessments and same-week visits during extended damp periods. Response times vary; request written lead times and ask about after-hours options when persistent leaks or mold odors appear.