Hiawatha Elementary School HVAC Upgrades
Built in 1954, the Cedar Rapids Community School District’s Hiawatha Elementary School was still relying on components of its original HVAC system – including steam boilers and unit ventilators. Window air-conditioning units had been added over the years, but they didn’t cool spaces evenly and provided no central control capabilities.
The district wanted a new heating and cooling system that would improve temperature control and reduce energy costs while ensuring that every classroom had access to air-conditioning.
To help Hiawatha Elementary School select a replacement system for its steam boilers and unit ventilators, Shive-Hattery investigated nearly a dozen options and compared differences in upfront and lifecycle costs. This data helped Cedar Rapids Community School District leaders narrow in on the ideal solution: a one-pipe geothermal system that allows each classroom, small groups of offices, and educational space to have individual thermostats that control temperatures independently.
Shive-Hattery drilled down into the aquifer to establish a supply well and connect directly to a groundwater source. Groundwater is taken from the supply well through one side of a double wall heat exchanger and then to a reinjection well that puts the water back into the aquifer, creating an open loop system. The building water loop is circulated through the other side of the double wall heat exchanger allowing heat to be extracted from or heat to be injected into the groundwater system.
To make the most of its HVAC system replacement, Hiawatha Elementary School also replaced all windows and exterior doors. This ensures that the building envelope is efficient enough to keep heated and cooled air inside.
Hiawatha Elementary School’s HVAC upgrades helped the Cedar Rapids Community School District earn $498,532 in energy-efficiency rebates from the local utility. This mechanical project is expected to reduce energy use in the building by more than 2.5 million kilowatt-hours annually.
Instead of turning on boilers in early fall and leaving them on through late spring, Hiawatha Elementary School teachers, staff, and students now experience consistent, comfortable temperatures that can be controlled individually as needed based on occupancy, time of day, etc. The district can also monitor and operate the HVAC system remotely for added comfort and energy efficiency.