An Energy Recovery Ventilator (ERV) is a mechanical ventilation system that exchanges stale indoor air with fresh outdoor air while recovering both heat and humidity from the outgoing air stream. It’s designed to improve indoor air quality and energy efficiency, especially in well-sealed buildings.
How It Works
An ERV system uses a heat exchanger core, usually made from a semi-permeable membrane or specially designed material, to transfer sensible heat (temperature) and latent heat (moisture) between incoming and outgoing air streams. This exchange occurs without mixing the air, ensuring clean and efficient ventilation.
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In winter: Warm, humid indoor air preheats and humidifies the incoming cold, dry outdoor air.
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In summer: Cool, drier indoor air pre-cools and dehumidifies the incoming warm, moist air.
Key Components
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Supply and exhaust fans: Pull fresh air in and push stale air out.
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Heat exchanger core: Allows energy transfer (heat and humidity) between air streams.
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Filters: Clean incoming and outgoing air to remove dust, pollen, and pollutants.
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Controls: Manage airflow rate, timers, and integration with HVAC systems.
Benefits of ERV Systems
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Improved indoor air quality: Constant fresh air flow reduces CO₂, VOCs, and odors.
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Energy savings: Recovers up to 60–80% of heat and moisture energy that would otherwise be lost.
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Humidity control: Helps maintain a comfortable indoor humidity level year-round.
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Balanced ventilation: Equal supply and exhaust airflow reduces pressure imbalances in the building.
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Longer HVAC life: Reduces load on heating and cooling equipment.
Common Applications
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Residential homes
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Office buildings
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Schools and universities
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Hospitals and healthcare facilities
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Energy-efficient or airtight buildings (e.g., Passive House)
Considerations for Installation
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Proper sizing is essential (based on square footage and occupancy).
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Needs ducting and potential integration with HVAC system.
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Regular maintenance required: filters and exchanger core need cleaning/replacement.