With the caveat that I have had a long day with low voltage wiring; thus, don't have much thinking left. What advantage do 2-stage W-W units offer? I'm thinking with proper controls and a buffer tank, there really isn't much benefit to 2-stage vs. 1.
One potential benefit would be less cycling of the compressor in first stage run. Longer cycles could benefit DSH utilization. With a large enough buffer, that becomes less of a factor, but space layout may limit buffer size.
Not to disagree with Trent, but I see no advantage to a two stage W2W. Refrigeration systems and boilers are at their best running full speed ahead. The tricks are in the buffering tank(s) and the piping. Control strategies are also important. Mark
Most of our work is radiant and I've not seen a fit for 2-stage yet. Just wondered if I was missing the obvious. We do stage multiple units.
