MURB In-Suite Electrification: Panel Management and Load Diet

Jan 2024

 

Can we switch from gas to in-suite electric heating systems without electric upgrades?

 

In-suite heat pumps offer a practical solution to reduce energy consumption and greenhouse gas emissions in multi-family buildings, while enhancing occupant comfort and safety with efficient heating and cooling. The FRESCo MURB In-Suite Electrification: Panel Management and Load Diet Report explores the feasibility of installing in-suite heat pumps in gas-heated multi-unit residential buildings (MURBs) without requiring upgrades to suite electrical capacity.   

The primary challenge to installing in-suite heat pumps in gas heated buildings is the limited electrical capacity and limited space for new circuits in existing suite panels.  The electrical infrastructure in gas-heated buildings was not originally designed to support all-electric systems and appliances. Without advance planning, the addition of electrical space heating, and other hard-wired loads such as EV charging, to an existing suite panel with limited capacity can result in overloading. Given electrical capacity upgrades can be costly, time-consuming, and perceived as a barrier to electrification, avoiding these upgrades can facilitate quicker and more cost-effective electrification retrofits in existing buildings.  

The report provides a deep dive into the topic. Key highlights include:  

  • The installation of in-suite heat pumps may be best enabled by a combination of minimizing electrical demand (e.g., specifying high-efficiency low-ampacity heat pumps), reducing in-suite electrical loads (i.e., load diet), and employing energy management systems (EMS) for load sharing.  

  • The installation of in-suite heat pumps on an existing suite panel is most viable in buildings that are already electrically heated, or in newer gas-heated apartments and townhomes that may also have sufficient electrical capacity. It may also be most viable in older gas-heated bachelor suites and small one-bedroom apartments, which make up a large percentage of BC apartment suites, given they likely only need one small heat pump.  

  • While in-suite panel upgrades may be avoided, the installation of heat pumps in a substantial number of suites is likely to trigger capacity upgrades to the main building electrical service, as the electrical infrastructure of gas-heated buildings was not originally designed to support every suite panel operating at or near full capacity.  

  • Lower cost in-suite electrification will be accelerated by finding solutions pathways to the identified regulatory barriers, improved market availability of EMS equipment and load-management friendly appliances and heat pumps, and increased industry awareness and expertise with building electrification.  

Download report here