Stop Mold Before It Starts - Portland HVAC Solutions
Portland's rain and humidity make mold a constant fight. We install UV-C lights, dehumidifiers, and air scrubbers that kill mold spores inside your HVAC system and keep them from coming back.
What Portland Homes Are Up Against
165 Rainy Days
We get more rainy days than any major U.S. city — that's constant moisture feeding mold growth.
Basement Moisture
Our clay soil and high water table mean damp basements are the norm — and mold loves every bit of it.
Crawlspace Issues
Crawlspaces stay wet for months here. That moisture migrates up through your floor and into your living space.
HVAC Coil Mold
Evaporator coils sit in the dark and drip condensation all summer — exactly what mold needs to thrive.
Attic Condensation
In older Portland homes, warm moist air from downstairs meets cold attic air in winter. That temperature difference causes condensation on insulation and ductwork — and that's where mold sets up shop.
Window Condensation
Those old single-pane windows sweat all winter. The moisture soaks into window frames and surrounding drywall, and mold follows right behind.
Mold Species We See Most in Portland
Aspergillus: Most Common (Black/Green Spots)
Shows up in basements, bathrooms, and HVAC systems — anywhere with persistent moisture. Triggers allergic reactions and respiratory problems.
Grows on cellulose materials like drywall, wood, and paper products.
Cladosporium: Olive-Green (Fabrics/Carpet)
Loves cool, damp conditions — so Portland is basically paradise for it. We find it on carpets, fabrics, and duct insulation regularly.
One of the most common airborne mold spores in Portland's moist climate.
Stachybotrys (Black Mold): Toxic
Grows on water-damaged drywall, wood, and paper products. Produces mycotoxins that cause serious health problems. If you find this one, call a remediation pro immediately.
Often called "toxic black mold" - serious health concern requiring immediate attention.
Penicillium: Blue/Green (Water-Damaged)
Spreads fast on water-damaged materials. Causes allergic reactions and can lead to infections in people with weakened immune systems.
Often found in flood-damaged Portland homes after heavy winter rains.
Health Effects of Mold Exposure
Allergies
Sneezing, runny nose, itchy eyes, skin rashes
Respiratory Issues
Coughing, wheezing, asthma attacks, bronchitis
Other Symptoms
Headaches, fatigue, sinus infections, fever
How We Attack Mold Through Your HVAC System
UV-C Lights: Kill Mold Spores
- •99.9% mold spore elimination in HVAC
- •Prevents regrowth on evaporator coils
- •Eliminates musty odors
- •Improves system efficiency
Cost: $600-$900 installed
Dehumidification: Control Moisture
- •Maintains humidity below 60%
- •Whole-home moisture control
- •Prevents mold growth conditions
- •Essential for Portland basements
Cost: $800-$2,000 installed
Air Scrubbers: Remove Spores
- •Captures airborne mold spores
- •Neutralizes mold odors
- •Continuous air purification
- •Works on surfaces too
Cost: $1,200-$2,000 installed
ERV/HRV Systems: Fresh Air Exchange
- •Brings in fresh, filtered air
- •Controls indoor humidity
- •Dilutes indoor pollutants
- •Prevents moisture buildup
Cost: $1,500-$3,000 installed
Coil Cleaning & UV Treatment
Why HVAC Coils Get Moldy
Every time your AC runs, warm air passes over the cold evaporator coil and creates condensation. Add in organic debris and zero sunlight, and you've got a mold incubator. That mold acts like insulation on the coil — killing efficiency while circulating spores through every room.
Studies show 80% of HVAC systems have some mold growth on coils.
Annual Coil Cleaning
During your annual tune-up, we pull mold, debris, and mineral scale off the coils. That alone can boost efficiency 15–30% and kill the musty smell. We use EPA-approved coil cleaners that get the job done without damaging your equipment.
Clean coils save energy and prevent mold spore circulation throughout your home.
UV-C Lights Prevent Regrowth
We install UV-C germicidal lights right next to the evaporator coil where they kill 99.9% of mold spores and bacteria on contact. Once installed, they run 24/7 — preventing regrowth between cleanings and keeping coils cleaner for better efficiency.
UV-C lights pay for themselves through improved efficiency and reduced cleaning frequency.
Our 5-Step Mold Prevention Plan
Step 1: Control Humidity (40-50% RH)
We install whole-home dehumidifiers and humidity controls to keep indoor levels at 40–50% RH. Below 60% is the critical threshold — mold simply can't grow without enough moisture.
Humidity control is the foundation of effective mold prevention.
Step 2: Ensure Proper Ventilation
ERV or HRV systems bring in filtered fresh air while exhausting stale, moisture-laden indoor air. This constant exchange prevents the stagnant conditions that let mold take hold.
ERV systems are essential for Portland homes to prevent moisture-related mold issues.
Step 3: Install UV-C Lights
Germicidal UV-C lights mounted near your evaporator coil run 24/7, sterilizing mold spores as air passes through. This targets the most mold-prone area of your system.
UV-C lights target mold at its source - in your HVAC where spores multiply.
Step 4: Fix Leaks Promptly
Fix roof leaks, plumbing drips, and foundation cracks as soon as you spot them. Water intrusion is the number one cause of mold in Portland homes — and it only takes 24–48 hours for mold to start growing.
Don't wait - water damage can lead to extensive mold problems within 24-48 hours.
Step 5: Annual HVAC Inspection
An annual tune-up catches mold early — before it spreads into a bigger problem. Clean coils and drain lines mean your system runs better and pushes cleaner air through every room.
Prevention is always cheaper than remediation - annual maintenance saves money long-term.
When It's Beyond HVAC — Call a Remediation Pro
Visible Mold Growth > 10 sq ft
Once mold covers more than 10 square feet, it's beyond what HVAC solutions can handle. You need specialized containment, removal, and treatment from a licensed remediation crew.
Large mold growth requires professional remediation to prevent spore spread and ensure complete removal.
Mold Behind Walls
When mold hides behind walls or in inaccessible areas, it's a structural issue. The remediation team will open walls, pull out contaminated materials, and clean everything properly.
Hidden mold can spread throughout the home's structure and affect indoor air quality significantly.
Post-Flood/Water Damage
After serious water events — flooding, sewage backup, or burst pipes — mold remediation is critical. Mold colonies can establish themselves within 48 hours of water exposure.
Flood damage requires immediate professional attention to prevent widespread mold contamination.
Persistent Health Symptoms
If allergy symptoms, respiratory issues, or other health problems stick around after HVAC mold treatment, you may need full mold remediation to address hidden sources behind walls or under floors.
We work with licensed mold remediation contractors and can connect you with one for thorough mold removal.
Tackling Basement & Crawlspace Mold in Portland
Basement Dehumidifiers
Most Portland basements need dehumidification running year-round. Groundwater seepage and ambient humidity are relentless. A whole-home dehumidifier tied into your HVAC system is the most effective fix.
Portland basements often need 50-70 pints per day moisture removal capacity.
Crawlspace Encapsulation
Encapsulation lays a vapor barrier across the entire crawlspace floor and walls, cutting off ground moisture at the source. It's a separate specialty service, but for mold prevention it's one of the most impactful things you can do.
We recommend sealing crawlspace ducts and ensuring proper encapsulation for maximum protection.
Ductwork in Crawlspaces
Ductwork in crawlspaces sits right in the most mold-prone zone of your home. We seal those ducts tight and add filtration so contaminated air from the crawlspace stays out of your living areas.
Crawlspace ducts should be sealed and pressurized to prevent mold spore migration.
Mold Prevention FAQs
Can HVAC upgrades really prevent mold in Portland's climate?
Absolutely. UV-C lights kill 99.9% of mold spores passing through your system. Dehumidifiers hold humidity below 60% — the threshold where mold can't grow. And proper ventilation prevents moisture from building up. Combined, these tools hit mold at the source before it ever reaches your living spaces.
What's the best mold prevention solution for HVAC systems?
For most Portland homes, UV-C lights plus a whole-home dehumidifier is the strongest combination. The UV kills spores inside the system, the dehumidifier keeps your whole house below 60% RH, and if you add an ERV, you get fresh air exchange on top. Start with UV and dehumidification — those give you the biggest bang for the money.
Do UV-C lights kill all types of mold?
UV-C lights kill 99.9% of mold spores and other microorganisms they contact. But UV-C only works on what passes through the air stream or sits within range of the light — it won't penetrate porous materials or reach mold behind walls. For full mold control, pair UV-C with humidity control and proper ventilation.
How do I know if I have mold in my HVAC system?
Musty smell coming from the vents is the most common sign. Other red flags: visible mold on evaporator coils, reduced airflow, rising energy bills, or allergy symptoms that get worse when your system runs. We check for mold during every annual tune-up, but if you're noticing these issues now, schedule an inspection.
What's the difference between mold prevention and mold remediation?
Prevention means creating conditions where mold can't grow — controlling humidity, improving ventilation, and sterilizing with UV light. Remediation means removing mold that's already established and repairing the water damage that caused it. Prevention costs a fraction of remediation. We handle the prevention side and can refer you to licensed remediation contractors when needed.
How much does HVAC-based mold prevention cost?
UV-C lights alone run $600–$900 installed. Add a whole-home dehumidifier and you're looking at $1,400–$3,000 total. ERV/HRV systems add another $1,500–$3,000 depending on the install. Costs vary by home size and system complexity. Some of these qualify for Energy Trust of Oregon rebates — we'll walk you through what applies.