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Heat Recovery Ventilation

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Heat Recovery Ventilation

The core component of an the system is the heat exchanger, which allows heat to be transferred from the warm air leaving the building to the cold air entering it, without the two air streams mixing.


Heat Recovery Ventilation (HRV)

Heat Recovery Ventilation (HRV) is a mechanical ventilation system designed to improve indoor air quality while also recovering and reusing a significant portion of the heat that would otherwise be lost during the ventilation process. HRV systems are particularly effective in climates where outdoor temperatures are significantly different from indoor temperatures.

Heat Recovery Ventilation is a valuable addition to residential, commercial, and industrial buildings, especially in colder climates. It combines energy efficiency with improved indoor air quality, contributing to a healthier, more comfortable, and environmentally conscious living and working environment.

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    How Heat Recovery Ventilation Works:

  • Exhaust Air: Stale indoor air is extracted from the building through exhaust vents, typically located in areas such as bathrooms, kitchens, and utility rooms.
  • Heat Exchanger: The HRV unit contains a heat exchanger, which is a core component of the system. This heat exchanger allows heat to be transferred from the warm outgoing indoor air to the cold incoming outdoor air without the two air streams mixing. There are different types of heat exchangers, including plate, rotary, and enthalpy wheel heat exchangers.
  • Fresh Air Supply: Fresh outdoor air is drawn into the HRV unit through intake vents. As the incoming outdoor air passes through the heat exchanger, it gets pre-warmed by the heat from the exhaust air.
  • Heat Recovery: The heat exchanger enables the transfer of heat from the exhaust air to the incoming fresh air, thus significantly reducing the energy required to heat the incoming air during the winter months.
  • Balanced Airflow: HRV systems maintain balanced airflow by providing equal rates of exhaust and supply air, preventing pressure imbalances within the building.
  • Indoor Air Quality: The continuous supply of fresh outdoor air ensures that indoor air quality is maintained by diluting indoor pollutants and expelling stale air.


Benefits of Heat Recovery Ventilation:

  • Energy Efficiency: By recovering and reusing heat from the exhaust air, HRV systems significantly reduce the energy required to heat incoming fresh air. This leads to energy cost savings and a smaller carbon footprint.
  • Improved Indoor Air Quality: HRV ensures a consistent supply of fresh outdoor air, expelling indoor pollutants, allergens, and odors.
  • Consistent Indoor Temperatures: Pre-warming the incoming outdoor air contributes to maintaining more stable indoor temperatures, preventing sudden drafts and temperature fluctuations.
  • Humidity Control: HRV systems can help manage indoor humidity levels, preventing excessive dryness in winter and excessive moisture in summer.
  • Health and Comfort: A healthier indoor environment, better air quality, and consistent temperatures contribute to occupant health, comfort, and well-being.
  • Moisture Control: By controlling humidity levels, HRV systems help prevent issues like condensation, mold growth, and damage to building materials.
  • Reduced Condensation: In cold climates, HRV systems help reduce the potential for condensation on windows and other surfaces.
  • Regulatory Compliance: HRV systems can help buildings meet ventilation standards and codes while still achieving energy savings.

Discover the future of Domestic Ventilation

Hercuglas sources and provide specialist ventilation products for the residential and commercial sectors.


Heat Recovery Ventilation (MVHR)

The main appeal of Heat Recovery Ventilation (MVHR) is the supply of warm, fresh, filtered ait to habitable rooms and the extraction of moist and stale air from bathrooms, utility rooms and kitchens.

The benefits of heat recovery stretch beyond just simple energy savings. By reducing humidity and condensation, which can cause health problems and affect the buildings fabric, it greatly improves the indoor air quality and wellbeing of occupants.

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  • Heat Recovery: ERVs include a heat exchanger that transfers heat from the outgoing indoor air to the incoming outdoor air during the heating season. This helps to pre-condition the incoming air and reduce heating costs.
  • Energy Efficiency: By recovering and reusing heat from the exhaust air, ERVs reduce the overall energy consumption required for maintaining indoor comfort.
  • Fresh Air Supply: ERVs ensure a continuous supply of fresh outdoor air while expelling stale indoor air, contributing to improved indoor air quality.
  • Air Filtration: Many wall-mounted ERVs incorporate air filters to remove dust, pollen, allergens, and other particulates from the incoming air, enhancing indoor air quality.
  • Humidity Recovery: Some advanced models feature a humidity recovery mechanism, which transfers moisture between the incoming and outgoing air streams. This helps control indoor humidity levels.
  • Balanced Airflow: ERVs maintain balanced airflow by providing equal rates of supply and exhaust air, preventing pressure imbalances within the building.
  • Quiet Operation: Manufacturers prioritize quiet operation, ensuring minimal noise disturbance in occupied spaces.
  • Control Options: Wall-mounted ERVs often come with user-friendly control panels or interfaces that allow users to adjust settings like fan speed, ventilation rates, and operating modes.
  • Easy Installation: Designed for easy installation, these units are suitable for retrofitting or adding ventilation to specific rooms without extensive modifications.
  • Compact Design: Wall-mounted ERVs have a compact form factor that makes them suitable for smaller spaces or areas with limited installation options.
  • Maintenance Indicators: Some units include alerts or indicators that remind users when it's time to replace filters or perform routine maintenance tasks.
  • Energy-Saving Modes: Certain models may offer energy-saving modes that adjust ventilation rates based on occupancy or time of day to further optimize energy usage.
  • Aesthetics: Many manufacturers offer modern and aesthetically pleasing designs to seamlessly blend with interior spaces.
  • Duct Connections: Wall-mounted ERVs have specific ports for supply and exhaust ducts, ensuring proper airflow and ventilation distribution.
  • Environmental Considerations: The energy recovery process contributes to reduced carbon emissions and environmental impact, promoting sustainability.

10 Benefits of the Energy Recovery Ventilation (ERV) and Heat Recovery Ventilation (HRV)


1. Improved Indoor Air Quality (IAQ):

ERV and HRV systems provide a continuous supply of fresh outdoor air while expelling stale indoor air. This helps maintain a healthier indoor environment by reducing the concentration of pollutants, odors, and contaminants.

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2. Energy Efficiency:

Both ERV and HRV systems recover a portion of the energy that would otherwise be lost through ventilation. They use heat exchangers to transfer heat from the outgoing indoor air to the incoming outdoor air.

In heating seasons, recovered heat helps pre-condition the incoming cold air, reducing the load on the heating system.

In cooling seasons, ERV systems can also transfer moisture, reducing the load on the cooling system by dehumidifying the incoming air.

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3. Reduced Heating and Cooling Costs:

By recovering heat in the winter and coolness in the summer, ERV and HRV systems help maintain a more stable indoor temperature. This reduces the need for excessive heating or cooling, resulting in energy cost savings.

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Digital temperature and humidity control in baby room

4. Humidity Control:

ERV systems can transfer moisture in addition to heat. This helps maintain balanced indoor humidity levels, preventing issues such as condensation, mold growth, and discomfort.

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5. Comfort:

Pre-conditioning the incoming air through heat recovery ensures that indoor temperatures remain consistent, avoiding sudden drafts or extreme temperature variations.

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Plant by apartment's window in winter - Air cleaning plant Aloe Vera to clean air from toxic chemicals - natural purifier indoors in condo building.

6. Odor and Pollutant Removal:

ERV and HRV systems help remove indoor odors and pollutants, ensuring a more pleasant and comfortable living or working environment.

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Construction and structure concept of Engineer or architect meeting for project working with partner and engineering tools on model building and blueprint in working site.

7. Compliance with Building Codes:

Many building codes and standards recommend or require a certain level of ventilation. ERV and HRV systems can help buildings meet these ventilation requirements while still achieving energy savings.

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8. Environmental Impact:

Reduced energy consumption translates to lower greenhouse gas emissions and a smaller carbon footprint, contributing to environmental sustainability.

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9. Preservation of Indoor Heat/Coolness:

In cold climates, HRV systems help retain indoor heat during ventilation, making it easier to maintain a comfortable temperature.

In hot and humid climates, ERV systems can remove excess humidity from incoming air, improving indoor comfort.

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10. Reducing Outdoor Contaminant Infiltration:

ERV and HRV systems help control the entry of outdoor pollutants, allergens, and particulates into the indoor environment.

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10 STEPS TO INSTALLING Energy Recovery Ventilation (ERV) and Heat Recovery Ventilation (HRV)

1. System Design and Sizing:

  • Calculate the ventilation requirements based on the building's size, occupancy, and local codes.
  • Determine the appropriate ERV/HRV unit size based on the calculated ventilation needs and the expected heat recovery efficiency.

2. Site Selection and Ductwork Planning:

  • Choose a suitable location for installing the ERV/HRV unit. Typically, this should be a central location with easy access to both indoor and outdoor air intakes and exhausts.
  • Design the ductwork layout for air distribution, considering supply and exhaust connections to various rooms and areas in the building.
  • Plan the route for the outdoor and exhaust ducts to ensure optimal airflow and minimize obstructions.

3. Duct Installation and Outdoor and Exhaust Vent Installation:

  • Install the ductwork according to the planned layout, making sure to insulate the ducts properly to prevent heat loss or gain.
  • Install outdoor air intake and exhaust vents. The outdoor air intake should be placed in a location with minimal outdoor pollutants, and the exhaust vent should direct stale air away from the building.

4. ERV/HRV Unit Installation:

  • Mount the ERV/HRV unit on a stable surface in the chosen location. Make sure to follow the manufacturer's guidelines for clearances and installation instructions.

5. Electrical Wiring and Duct Connection:

  • Connect the ERV/HRV unit to the electrical supply following the manufacturer's instructions. This includes connecting the unit to power and any necessary control wiring.
  • Connect the supply and exhaust ducts to the appropriate ports on the ERV/HRV unit. Ensure proper sealing to prevent air leaks.

6. Condensate Drainage and Controls and Settings:

  • If your system includes a condensate drain, ensure that it is properly connected to the ERV/HRV unit and that it drains away from the unit and the building's foundation.
  • Set up the controls for the ERV/HRV system, including setting desired ventilation rates, fan speeds, and other parameters.

4. Balancing and Testing and Insulation and Sealing:

  • Once the system is installed, balance the airflow by adjusting dampers and registers to ensure even air distribution throughout the building.
  • Perform system tests to ensure that the ERV/HRV unit is functioning properly and effectively transferring heat or moisture.
  • Insulate any exposed ducts to prevent heat loss or gain and ensure efficient energy recovery.
  • Seal all duct connections, joints, and openings to prevent air leaks that could compromise system efficiency.

4. Maintenance and Operation Instructions:

  • Provide the building owner with information about proper operation, maintenance, and cleaning of the ERV/HRV system. This includes regular filter replacement and cleaning to ensure optimal performance.

4. Compliance and Inspection:

  • Ensure that the installation complies with local building codes and regulations.
  • If required, schedule inspections to verify the installation's compliance and safety.

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