Carriage House: Retrofit with Heat Pumps, Smart Controls, and IAQ Upgrades

Project Background

SWA took Carriage House through a multi-step process to reduce annual energy spend by over $235k, beginning with site scoping and auditing, then design, construction phase oversight and testing, and a full year of measurement and verification. Over $1M in incentives were secured for this project.

Energy Conservation Measures

The client implemented four ECMs: a heating and cooling system upgrade from packaged terminal air conditioners (PTACs) to packaged terminal heat pumps (PTHPs) with a central
controls system, a ventilation upgrade, a water pressure booster pump replacement, and control of the elevator machine room smoke vent. Despite a 9% percent increase in occupancy due to the COVID-19 lockdown, the ECMs resulted in a 41% reduction in site energy use.

Heat Pumps with Smart Controls

Converting to heat pumps with smart in-unit and central controls resulted in a 27% reduction in site energy usage, making this upgrade the champion ECM.

IAQ

44% of apartments tested had below-target ventilation rates when SWA arrived at the building. They all met ventilation targets by the end of the project. Additionally, fresh air was introduced to the building via two new energy recovery ventilation systems that were verified to meet 80% of the fresh air heating load through passive means.