Adam Romano: PH Domestic Hot Water

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Last week at Construction Tech Tuesday our cohosts Kevin Brennan, Shaun St-Amour, and Mark Wille welcomed Adam Romano, a senior buildings system consultant at Steven Winter Associates, to plunge deep into the specifics of domestic hot water (DHW) systems. He did not disappoint. In what may have been the most technical episode of Construction Tech Tuesday to date, Adam provided a nearly breathless presentation on the technical, the technique, and the technology behind these systems.

Adam’s 30-minute presentation provides some context for the current technologies that are employed in most traditional DHW systems before looking into how we can optimize systems through future-forward technologies and carbon reduction strategies for both single- and multifamily buildings. As Adam explains, most traditional systems rely on natural gas-fired water heaters or hydronic distribution systems where boilers feed indirect tanks.

These will eventually be replaced by more efficient, refrigerant-based systems, especially in Passive House or other high-performance buildings that are all electric. Some utilize integrated heat pump water heaters that can take ambient heat from the building environment and transfer that energy to the water. The second kind of system is the split heat pump water heater, which takes heat from outside the building envelope and injects it into the water. In either case, the type of refrigerant used within the system is extremely important since some of these molecules (e.g. fluoroform) have a global warming potential (GWP) that is more than 14,000 times more potent than carbon dioxide. Should they leak into the atmosphere, they can do serious damage.

To see how these systems performed in real world scenarios, as well as everything you’ve ever wanted to know about DHW systems but have been afraid to ask, check out Adam’s full presentation here: