Heat recovery for space heating is a highly efficient and cost-effective way to improve indoor air quality and reduce energy bills. By capturing and reusing heat that would otherwise be wasted during the ventilation process, heat recovery ventilation (HRV) systems can provide significant energy savings and improve the overall performance of HVAC systems.
Understanding Heat Recovery Ventilation (HRV) Systems
HRV systems work by pulling stale air from inside a building, where it can contain particulates, odors, and humidity. This air also contains a significant amount of heat energy, which would be wasted if it was sent directly out through the ventilation system. Instead, the exhausted air is routed into a highly efficient heat exchanger inside the HRV.
The heat exchanger is equipped with heat transfer plates that collect and transfer heat through several air channels. On the other side of the heat exchanger’s plates, a stream of fresh air is pulled in from outside the building, where it makes contact with the plates and absorbs a major portion of the heat that has been recovered from the exhausted air flowing out through the system. The two streams of air do not mix or mingle in any way, ensuring that no contaminants are introduced into the incoming fresh air.
Technical Specifications of HRV Systems
- Heat Recovery Efficiency: Typically up to 80%
- Fresh Air Provision: HRVs can provide fresh air to a building while recovering and recycling much of the heat that would otherwise be lost during the ventilation process.
- Optimal Installation: HRV systems are most effective when installed in an attic or upstairs space, where they can serve as a whole-structure ventilator.
- Air Flow Rates: HRV systems are designed to provide a balanced air flow, with equal amounts of fresh air intake and stale air exhaust, typically ranging from 50 to 200 cubic feet per minute (CFM) for residential applications and up to 2,000 CFM for commercial buildings.
- Energy Savings: HRVs can capture and recycle up to 80% of the heat that would otherwise be lost during the ventilation process, resulting in significant energy savings.
Benefits of Heat Recovery Ventilation
- Improved Indoor Air Quality: HRVs provide a steady supply of fresh, pre-warmed air, which reduces the need for heating and extends the life of the HVAC system.
- Energy Efficiency: By recovering and reusing heat that would otherwise be wasted, HRVs can significantly reduce the energy required for space heating, leading to lower utility bills.
- Reduced Stress on Heating Equipment: HRVs help to reduce the workload on heating equipment, as they provide a steady supply of pre-warmed air, which reduces the need for the heating system to work as hard.
- Increased Comfort: The consistent supply of fresh, pre-warmed air from an HRV system can help to maintain a more comfortable and consistent temperature throughout the building.
- Improved Ventilation: HRVs ensure that stale, contaminated air is effectively removed from the building, while fresh, filtered air is continuously supplied, improving overall indoor air quality.
Considerations for DIY Heat Recovery for Space Heating
While it is possible to install a heat recovery ventilation system as a DIY project, it is generally recommended to consult with a professional HVAC contractor or engineer. Installing an HRV system requires a certain level of expertise and knowledge of HVAC systems, and should be done by a qualified professional to ensure proper installation and operation.
Some key considerations for a DIY HRV installation include:
- Proper sizing and selection of the HRV unit based on the size and layout of the building
- Correct placement and integration of the HRV system with the existing HVAC ductwork
- Ensuring proper airflow balancing and ventilation rates
- Compliance with local building codes and regulations
- Proper maintenance and servicing of the HRV system over time
By working with a professional HVAC contractor, homeowners and building owners can ensure that their heat recovery ventilation system is installed correctly and operates efficiently, maximizing the energy savings and indoor air quality benefits.
Conclusion
Heat recovery for space heating is a highly effective and efficient way to improve indoor air quality and reduce energy costs. By capturing and reusing heat that would otherwise be wasted during the ventilation process, heat recovery ventilation systems can provide significant energy savings and improve the overall performance of HVAC systems. While DIY installation is possible, it is generally recommended to work with a qualified HVAC professional to ensure the system is properly designed, installed, and maintained for optimal performance.
References:
- Heat Recovery Ventilation for Your Commercial Space: What Is It? https://www.sobieskiinc.com/blog/heat-recovery-ventilation-your-commercial-space-what-it/
- How Do Heat Recovery Systems Work? – BPC Ventilation https://www.bpcventilation.com/blog/do-heat-recovery-systems-work/
- Heat recovery ventilation – Wikipedia https://en.wikipedia.org/wiki/Heat_recovery_ventilation