Kelly Burnham  | 

Hey Bob,
Thanks for your comments. We are using 500 gal horizontal propane tank and Yes, there are (2) Brazed plate heat exchangers between the OWB and the load loops (3). It would appear that the recommended orientation of the tank is Vertical, where this is not possible/practial in this installation. The tank will be horizontal so the inlet will be at one end at low level and the outlet at the opposite end at high level. Given that propane tanks are pressure rated for 200+ psi and the closed loop is operating at 10 to 12 psi it should be acceptable to pipe the tank into the (closed) load loop, where corrosion would be mitigated - which is a good idea.

Question: Given that the intended use of the tank is to provide thermal storage for the greenhouse, would it make sense then to pipe the tank in series with the loop that serves the greenhouse? All the loops are connected via common header so the thermal storage would serve all loads indirectly, e.g. house, garage, shop, etc.