Residential Green Building Meeting Recap

The early months of 2018 have seen a surge of initiatives at USGBC MA’s Residential Green Building Committee (RGBC). After a handoff of in December from Kimberly Le, new co-chairs Molly Cox of Civic Solar and Bill Womeldorf of ICF have stepped up with energy and creativity to launch new programs for the coming year. Projects include educational presentations to the public and consumers on advances in the residential sector, a special event on building materials with embedded carbon (Dana Anderson), and educational outreach to Boston trade schools.

On display at the February 12th RGBC meeting was Bill Womeldorf’s vision on the reduction of carbon emissions in the state. In his presentation “Net Zero Residential Sector in Massachusetts,” Womeldorf emphasized the emerging third strategy for mitigating greenhouse gases (GHG) through electrification of space thermal regulation and domestic hot water (DWH). This analysis echoes the concern of a growing cohort of experts that the two established schemes, energy efficiency and renewable energy, will fall short of achieving the 80 x 50 reduction goals mandated by the northeastern states.

Drawing on his experience as Energy Efficiency Policy Consultant with ICF, Womeldorf outlined the challenge of large quantities of energy consumed and GHG emitted by buildings through combustion processes in Massachusetts. Historically, single-family and multifamily space heating and cooling have trended from central fossil fuel furnaces generating steam to water radiators and recently to electric heat pumps. The obstacles DHW presents for heat pumps applications was also addressed. According to Womeldorf and a consensus of experts, air source heat pumps (ASHP) are the technology of choice for electrification of space thermal conditioning.

Womeldorf offered two case studies of ASHP system installations in Western Massachusetts. The 55 unit Northampton Lumber Mill Apartments was fitted with gas-fired, central plant domestic hot water system and variable refrigerant flow (VRF) with heat recovery space conditioning system in the residential units and common areas. An energy recovery ventilation with fresh air supply into the dwelling 135 units in Amherst included gas central plant domestic hot water system along with ducted and ductless air source heat pumps for space conditioning.

Womeldorf’s discussion of advances in renewable energy included new applications such as community solar and storage, both on-site and grid level. He concluded his talk with the provocative question: “how to mandate or make attractive electric heating systems when gas is king”?

Womeldorf’s assertion of concern about the dominance of gas is significant for several reasons. The imperative of GHG reduction for the well-being of the planet may be self-evident. Facts about the overall efficiency of air source heat pumps (ASHP) compared with conventional systems may be established. Nonetheless, arguments for electrification of space conditioning continue to face reservations about cost competitiveness. Verification is hampered by a deficit of data on outlays for ASHP installation and operation against expenditures for conventional gas systems. High rates in the northeast for electricity required for heat pumps are yet another factor.

Although ASHP technology in the last decade has made advances, qualified designers and installers are apparently in short supply. Furthermore, the paradigm shift of using more electricity and not less may be problematic to process for engineers and architects with traditional training.

Thus “gas is king” is due to a range of challenges, including those of information, training, economics, and policy. Wolemdorf acknowledged the programs by Massachusetts agencies and utilities which, in part, are addressing the gaps. If the 80×50 goals of the northeastern states are to be achieved, electrification will need to take effect on a larger scale by strategically targeting emissions from transportation and industry along with those from buildings.