This month, I am continuing my series on commissioning “simple” HVAC equipment with hydronic unit heaters. These are about as ubiquitous and low-tech as any equipment in a new building and, therefore, are prone to being nearly ignored by designers, contractors, and commissioning professionals.
Although simple, unit heaters are typically very important and used where the risk of freeze damage is high (e.g., vestibules, utility rooms, stairwells, loading docks). In addition to these devices needing to provide heat upon demand during cold weather, the design team may specify controls intended to minimize energy consumption when heating is not needed. Therefore, the commissioning professional must take them seriously during design review, controls integration, balancing, and testing.