Editor’s Note: The following post is written by guest blogger David Cohan Senior Advisor with the Institute for Market Transformation (IMT). C-PACE is an excellent financing tool to pair with a VHE HVAC upgrade.
This post reviews the problems with the standard electrification approach (swap heat pumps for gas-fired heating equipment) and a better solution – Very High Efficiency HVAC – suitable for many commercial building types.
Building electrification is a key strategy for achieving the goal of an emissions-free global energy economy. As more building owners become aware of this, they are looking for ways to electrify that make sense both technically and economically. The default solution is to simply remove gas-fired heating equipment and replace it with heat pumps, eliminating the use of on-site fossil fuels. Problem solved (but not)!
Heat pumps are important, but installing them without making other changes to the HVAC system can have a variety of negative impacts:
- Increased electrical demand necessitating expensive upgrades to the electrical service.
- Increased utility bills. In most parts of the country, the price of electricity is significantly higher than the price of natural gas. Even if the heat pumps are more efficient, the cost will usually be higher.
- Continuation of poor ventilation and indoor air quality. Replacing heating and cooling equipment will not, by itself, do anything to improve these.
- Increased emissions. If the electrical grid serving a building is powered by coal and natural gas plants, electrification may simply shift emissions from Scope 1 (the building) to Scope 2 (the power plants) without any reduction occurring. If the new heat pumps increase electricity use and the power plants providing that electricity are less efficient than the old gas-fired heating equipment, overall emissions can actually increase. The arguments for building electrification assume that the grid is increasingly powered by renewable energy but the pace at which this is happening varies dramatically from region to region.
To avoid these negative possibilities, what is needed is electrification that does not increase demand and also does not increase electricity use. And if that approach simultaneously improves ventilation and indoor air quality, that would be amazing. Such an approach exists. Very High Efficiency (VHE) HVAC has been successfully installed and validated in twenty buildings (and counting). In Tarrytown, NY a 71,000 square foot office building replaced 24 gas-fired rooftop units with a VHE HVAC system. Natural gas use fell by 97%, electricity use was reduced by 34% and peak electrical demand was reduced by 25% with the results validated by Pacific Northwest National Laboratory. Multiple other examples exist of buildings that achieved similar results.
VHE HVAC is not a specific product or technology. It is a performance-based, technical specification that optimizes the entire HVAC system. The key elements are:
- Ventilation system completely separated from the heating/cooling system, allowing each to be optimized to meet the building’s needs.
- High efficiency heat/energy recovery ventilation that recovers a minimum of 85% of the energy used to heat or cool the inside air.
- High performance electric heat pump system.
- Right-sized heating and cooling system. Most systems are highly over-sized, reducing the overall system efficiency.
The full VHE HVAC specification can be seen at imt.org/vhehvac/spec. The approach uses high efficiency versions of equipment that are widely available through multiple manufacturers, including all of the major heat pump manufacturers. The equipment is familiar to industry designers and installers so the approach can be replicated and scaled without requiring extensive or specialized training. VHE HVAC is widely applicable in typical commercial buildings (office, retail, education, public assembly, restaurants, etc.). Because it is a systems approach, it requires replacement of all the equipment in a zone or a building. This needs to be considered when deciding whether VHE HVAC makes sense for a specific building. High-rise buildings and multifamily buildings are feasible but have more limited applications.
For more information, contact David Cohan at firstname.lastname@example.org or visit www.imt.org/vhehvac. The Institute for Market Transformation is a national nonprofit organization that partners with government, business, and philanthropy to improve the efficiency and performance of the places we live, work, and learn.
To view this original post please visit the Philadelphia C-PACE website.