With 287 units, Jefferson Terrace is the largest Seattle Housing Authority (SHA) apartment building. FSi has worked on many projects in the building, including several projects keeping the steam-based heating and hot water system working for building residents.

When SHA decided to convert the building from steam to natural gas, they chose FSi as the prime consultant and mechanical engineer for the project.

Our project replaced the building’s steam-powered heating and domestic hot water system with high-efficiency natural gas condensing boilers and water heaters. The project also updated the heating water distribution to maximize boiler efficiency. For further energy savings, SHA replaced pneumatic boiler room controls with a DDC system that allows variable flows and temperature resets. The efficient new system reduced operating costs by more than $95,000 in the first five months of operation.