Fresh Air Without the Energy Hit - ERV & HRV Systems
ERVs and HRVs bring filtered fresh air into your home while recovering 70-80% of the heating or cooling energy. For tight Portland homes dealing with stale air, wildfire smoke, and moisture - this is how you ventilate without wasting energy.
What Are ERV & HRV Systems?
HRV (Heat Recovery Ventilator)
- •Exchanges heat only between incoming/outgoing air
- •70-80% heat recovery efficiency
- •Best for dry climates
- •Lower cost option
ERV (Energy Recovery Ventilator)
- •Exchanges heat AND humidity
- •70-90% energy recovery efficiency
- •Perfect for Portland's humid climate
- •Controls indoor humidity levels
How They Work
Fresh Air Intake
Brings filtered outdoor air indoors
Heat Exchanger
Transfers energy between air streams
Exhaust Air Out
Removes stale indoor air and pollutants
Result: Continuous fresh air circulation without losing heating/cooling energy or wasting money on expensive air conditioning.
Why Tight Portland Homes Need Mechanical Ventilation
Modern Homes Are Too Airtight
Energy-efficient construction and insulation create air-tight homes that trap indoor pollutants. Without proper ventilation, CO2 levels rise, humidity increases, and air quality deteriorates.
Indoor air can be 2-5x more polluted than outdoor air in tightly sealed homes.
Trapped Indoor Pollutants
VOCs from furniture and cleaning products, cooking odors, pet dander, and wildfire smoke infiltrate homes but can't escape without ventilation. ERV/HRV systems provide controlled fresh air exchange.
Proper ventilation is the foundation of good indoor air quality.
Moisture Buildup & Mold Risk
Portland's humid climate combined with airtight construction creates moisture problems. Excess humidity leads to mold growth in basements, crawlspaces, and bathrooms. ERV systems control humidity levels.
Portland homes have 165 rainy days/year - ventilation is essential for moisture control.
Radon & Other Concerns
Radon gas can accumulate in basements, and various odors from cooking, pets, and household activities build up without proper air exchange. ERV/HRV systems ensure continuous fresh air circulation.
ERV/HRV systems provide the fresh air your home needs without the energy penalty.
ERV vs HRV: Which for Portland?
ERV Recommended for Portland
Portland's humid climate makes ERV (Energy Recovery Ventilator) the superior choice. ERV transfers both heat and humidity, maintaining ideal indoor humidity levels year-round.
Summer: Dehumidification
Transfers moisture out, reducing indoor humidity from Portland's rainy weather
Winter: Adds Moisture
Prevents dry air from heating systems, maintaining comfort
Why ERV Works Better Here
- ✓Humidity Control: Essential in Portland's climate
- ✓Mold Prevention: Controls moisture that causes mold
- ✓Comfort: Prevents dry winter air and humid summer conditions
- ✓Efficiency: Better energy recovery than HRV
Cost Difference: $200-$400 More
ERV systems cost $200-$400 more than HRV due to the additional moisture transfer capability. This premium is justified in Portland's humid climate where humidity control is crucial for comfort and health.
Wildfire Smoke & ERV/HRV Systems
MERV 13-16 Filters on Fresh Air Intake
ERV/HRV systems can be equipped with high-efficiency filters on the fresh air intake to capture wildfire smoke particles. This provides filtered fresh air even during smoke events.
During smoke events, reduce fresh air intake rate and rely more on recirculation with HEPA filtration.
Smart Controls for Smoke Events
Modern ERV/HRV systems can be programmed to adjust ventilation rates based on outdoor air quality. During wildfire smoke, they minimize fresh air intake while maintaining some ventilation.
Better than opening windows during smoke season - provides controlled, filtered fresh air.
Protects Indoor Air Quality
While ERV/HRV systems bring in fresh air, they also help maintain indoor air quality by diluting indoor pollutants and providing controlled ventilation. This is crucial during extended periods of poor outdoor air quality.
ERV/HRV systems work alongside your HEPA filtration for layered wildfire smoke protection.
ERV/HRV Installation Options
Whole-Home ERV
Central ERV unit installed in attic or basement. Provides ventilation for entire home through existing ductwork.
- •Complete home coverage
- •Integrated with HVAC
- •Most efficient option
$1,500-$3,000 installed
Room-Based HRV
Individual units for specific rooms like kitchens, bathrooms, or home offices. Good for spot ventilation.
- •Targeted ventilation
- •Lower cost per room
- •Easy installation
$800-$1,200 per unit
Standalone System
Dedicated ventilation system with its own ductwork. Best when adding ventilation to existing homes without modifying current HVAC.
- •No HVAC modification
- •Independent operation
- •Flexible placement
$2,000-$3,500 installed
How Much Energy ERVs & HRVs Actually Save
70-90% Energy Recovery
ERV/HRV systems recover 70-90% of the energy from exhaust air, transferring it to incoming fresh air. This dramatically reduces the energy needed to condition incoming outdoor air.
Without energy recovery, ventilating your home costs 3-5x more in heating/cooling energy.
Reduced HVAC Load
By preconditioning incoming air, ERV/HRV systems reduce the workload on your heating and cooling systems. This extends equipment life and reduces operating costs.
15-30% reduction in ventilation energy costs.
Payback Period: 7-12 Years
Energy savings from ERV/HRV systems typically pay back the investment in 7-12 years through reduced heating and cooling costs. In Portland's moderate climate, payback can be even faster.
Energy Trust rebates available for qualifying ERV systems - further improving payback.
Installation Process (3-4 Hours)
Locate Fresh Air Intake
Choose optimal location for outdoor fresh air intake, away from exhaust vents, dryer vents, and sources of contamination. Typically on a sidewall or roof.
Install ERV Unit
Mount the ERV/HRV unit in attic, basement, or mechanical room. Position for easy access and proper drainage if applicable.
Connect Ductwork
Install intake and exhaust ducts, connecting to existing HVAC ductwork or creating dedicated ventilation pathways. Include proper filtration.
Wire Controls & Test
Connect electrical supply and integrate with thermostat or dedicated controls. Balance airflow and test all functions for proper operation.
Smart Controls & Automation
Adjustable Ventilation Rate
- •Variable speed control
- •Occupancy-based operation
- •Time-of-day scheduling
- •Remote control capability
Advanced Features
- •Humidity control mode
- •AQI-based operation (smoke detection)
- •Smart home integration
- •Filter replacement reminders
ERV/HRV FAQs
What's the difference between an ERV and an HRV?
An HRV transfers heat only between incoming and outgoing air streams. An ERV transfers both heat and moisture. In Portland's humid climate, ERVs are usually the better choice because they help manage indoor humidity — keeping it from getting too damp in spring and too dry in winter.
Do I need an ERV if my home already has good ventilation?
Most Portland homes don't actually have good ventilation — they rely on air leaking through cracks and gaps, which is inefficient and pulls in unfiltered pollutants. An ERV gives you controlled, filtered air exchange while recovering 70–90% of the energy. Critical for tight, well-insulated homes.
Will an ERV increase my energy bills?
Actually, the opposite. ERV/HRV systems save energy by recovering heat from the exhaust stream to precondition incoming air. That takes load off your furnace and AC. Expect 15–30% savings on ventilation-related energy costs — and cleaner air on top of it.
Can an ERV help during wildfire smoke events?
Yes, with the right setup. We equip the fresh air intake with high-MERV filters that catch smoke particles. During heavy smoke events, you can dial back the ventilation rate and supplement with HEPA recirculation indoors. Still way better than opening windows when the AQI is 200+.
How much does ERV installation cost in Portland?
Whole-home ERV: $1,500–$3,000 installed, depending on system size and complexity. Room-based HRV units: $800–$1,200 each. Standalone systems: $2,000–$3,500. Energy Trust of Oregon rebates can knock up to $500 off qualifying installations.
How often does an ERV need maintenance?
Annually: filter cleaning or replacement ($50–$100), core cleaning if needed, and a system inspection. Most ERV/HRV filters are washable and last 1–2 years. We check everything during your annual tune-up to keep it running at peak efficiency.