by Philip Steiner
Electrification of heat refers to the process of heating buildings using electricity rather than on-site fossil fuels. The majority of existing heating systems rely on carbon-based fuels—typically oil, propane, or natural gas—as their primary heat source. Whether serving individual buildings, such as single-family residences, or centralized heating plants, such as those found on university campuses, fuel was transported to the site and combusted as needed.
The U.S. Energy Information Administration (EIA) estimates that space heating and domestic hot water account for approximately 60% of energy use in residential buildings and 32% in commercial buildings. This equates to roughly 8 trillion BTUs annually, primarily generated through on-site fuel combustion in equipment with efficiency rates ranging from 80% to 90%. These systems release greenhouse gases, excess heat, and particulate pollutants into the atmosphere.
To address these emissions, legislation such as New York City’s Local Law 97 of 2019 has been enacted. This law requires existing buildings larger than 25,000 sq. ft. to reduce carbon emissions by 40% by 2030 and by 80% by 2050. A variety of technologies can be deployed to meet these targets; among the most promising is heat pump technology. Heat pumps use electricity to extract heat from the outside air, ground, or water and transfer it into building heating systems.
Within our practice, we have developed innovative large-scale applications of heat pump technology. At a major Northeast university, we designed a system utilizing ground-source water-to-water heat pumps connected to geothermal wells as the primary heating and cooling source for a building of nearly 170,000sf.
Many colleges and universities operate year-round central heating and cooling plants with distribution piping networks serving multiple campus buildings. At a Northeast university, we employed an innovative strategy that uses the campus central chilled water system as a heat source for water-to-refrigerant heat pumps in a 31,000sf building. In this design, on the source side of the heat pumps, in winter heat is extracted from the chilled water return and discharged back into the chilled water supply at a lower temperature. In addition to providing cooling for the building, the heat pump load side then provides building heating independently of the campus heating system, through a Variable Refrigerant Flow (VRF) system. An additional benefit of this approach is a reduced load on the central chiller plant.
While the technology to reduce or eliminate on-site carbon emissions is readily available, there are practical limitations to widespread adoption. The most significant constraint is the capacity of the nation’s electric transmission grid. The U.S. Department of Energy (DOE) estimates that transmission capacity will need to expand to 2.4 to 3.5 times its 2020 level by 2050 to meet projected demand. This transmission bottleneck may limit the pace at which heating electrification can be deployed nationwide.
It is also important to recognize that while electrification of heat reduces on-site carbon emissions, it shifts emissions upstream to electric power generation facilities. According to the American Public Power Association, of the approximately 13 terawatts (TW) of power generation capacity in the U.S., natural gas accounts for 43%, coal for 15%, and wind, nuclear, solar, and hydro combine for about 35%. For electrification of building heating to result in meaningful overall carbon reductions, the electric grid must continue transitioning toward renewable energy sources and incorporate sufficient energy storage capacity.
As we enter 2026, a majority of Altieri projects will either pursue all-electric heating or will be designed to easily accommodate future transition to all-electric heating. We believe this is the future of heating system design, and we anticipate an increase in its adaptation as the grid becomes more reliable, adds more renewable energy sources and becomes less dependent on carbon based fuels.
Philip Steiner
Philip Steiner, PE, is managing director at Altieri.
