In my experience, domestic hot water (DHW) seems to be one of the most disrespected and overlooked building systems in the design/construction industry. I’m writing this month to raise awareness of the importance of commissioning DHW systems from design through startup and balancing.
This current state of disregard could be because a poorly performing DHW system is not a critical issue in many buildings. If DHW primarily exists for employee, student, or visitor hand-washing, few people are going to make a big stink about cold or tepid water coming out of restroom or breakroom faucets. Sure, they’ll complain, but they are not likely to quit their jobs or otherwise not return to the building because of it. In smaller versions of these facilities, the DHW systems could simply be single water heaters and a short recirculating hot water loop. However, as the buildings get larger and taller, delivery of DHW to restrooms and breakrooms becomes a nontrivial issue.