Article Written By: James Del Monaco
Responsible Approach To Decarbonization in An Existing Building
ASHRAE Journal, February 2023
Decarbonization in existing buildings presents many unique challenges and requires a well-thought-out approach to perform responsibly. The author recently presented a high-level approach to decarbonization in a campus setting in an Engineer’s Notebook column. This column will focus on the process of electrifying the hydronic heat-generating equipment in several buildings in a higher education setting.
Space heating needs have historically been met by using fossil fuels and combustion-based equipment to generate hydronic hot water. The primary generation equipment is generally inexpensive (boilers are ~$12–$30 per MBH), has high turndown (a number of manufacturers offer 20:1), and use an available, reliable resource for fuel. Building operators are familiar with operating and maintaining this equipment.
As we transition to electrifying the space heating system, heat pumps offer a viable option. Heat pumps have been commonplace in the industry for more traditional airside HVAC applications. More recently, heat pump technology is being used for hydronic heating applications and domestic hot water heating. Heat pumps have their own challenges, such as higher first costs, lower operating efficiency at higher supply temperatures and low ambient operating limitations.