Unlocking Building Heat Recovery

Harnessing the Power of Waste Heat to Decarbonize Buildings

For industrial and commercial facilities, simultaneous heating and cooling needs across a building, or even a single floor, bring challenges to both near-term energy management and long-term decarbonization. Combined, space heating and cooling and water heating account for around half of the energy consumed in U.S. commercial buildings.

Capturing and repurposing waste heat – a process known as heat recovery – represents a cost-effective approach for commercial and industrial buildings to significantly reduce their on-site energy use and greenhouse gas emissions.

How Does Heat Recovery Work?

Heat recovery involves the process of collecting and reusing thermal energy that would normally be lost, whether through ventilation exhaust, cooling towers, or wastewater. In other words, heat recovery enables buildings to store or reuse energy that’s already been paid for to cut energy costs and emissions.

Heat recovery systems can recycle wasted thermal energy through a variety of applications, including airside recovery, wastewater heat recovery, process heat recovery, flue-gas recovery, hydronic space heaters, and water-cooled air conditioners. This diversity of commercialized heat recovery solutions can accommodate varied building types and retrofit needs.

For example, airside heat recovery can be integrated in a ventilation system to transfer heat and moisture (during winter months) between the incoming supply air and outgoing exhaust. While the polluted air is transferred out, fresh air and energy savings are retained within the building.

Recapture Heat to Lock in Energy and Emissions Savings

Commercial, multifamily, and industrial buildings across New York are incorporating heat recovery systems in retrofit projects and new construction alike.

Watch Video 

In New York City, a 1931 office building, Hudson Square Properties, is installing multiple heat recovery systems. A dedicated outside air heat recovery system will provide fresh air ventilation, while a system of water source heat pumps will share heat within and across floors of the building to manage divergent heating and cooling needs between tenant spaces.

Heat recovery and clean energy retrofits will be installed to capitalize on tenant turnover within the 17-story office building and completely phase out fossil fuel equipment. Once fully electrified, Hudson Square Properties is expected to use 30% less energy and reduce emissions by 90% compared to the pre-retrofit baseline.

As the project proceeds, the property’s thermal energy network is designed with the capacity to connect to neighboring buildings, enhancing its long-term cost-effectiveness and scalability.

Brookfield Properties, a high-rise office building in Manhattan, is also prioritizing heat recovery in their building decarbonization plan. This includes installing water source heat pumps to recover heat from all its retail tenants.

Additionally, airside heat recovery will be integrated with dedicated outdoor air systems (DOAS). This technology can be integrated within a building’s HVAC equipment to precondition outside air brought into a building, translating to energy savings and increased indoor comfort.

Planning and Developing a Heat Recovery Strategy

Heat recovery is one of the first steps to building decarbonization and emissions reduction, following envelope improvements and optimizing controls and building systems. Further insights on where heat recovery fits in a phased approach to building electrification, a process known as Resource Efficient Decarbonization, can be found in the Retrofit Playbook for Large Buildings .

While heat recovery solutions have been incorporated in all retrofit projects funded through the Empire Building Challenge, this energy-saving equipment is not limited to high-rise buildings.

Given the variety of solution types, beginning with an assessment is recommended to identify opportunities and tailor a heat recovery system to complement the building design and existing equipment. Commercial and industrial properties can access cost-share support through NYSERDA’s Heat Recovery Program to complete an assessment of a building’s heat recovery potential. Building owners who are farther along in the process can apply for funds to support heat recovery project design and demonstration projects.

Commercial and industrial properties can also leverage Inflation Reduction Act (IRA) tax credits, namely the 179D Commercial Buildings Energy-Efficiency Tax Deduction, to reduce the cost of a heat recovery system and fund building decarbonization. Buildings must reduce their total annual energy use by at least 25% to be eligible for the IRA tax credit.