Heat pump water heater reality check

STM · 07-11-16, 07:53 AM

Criticize me here. Want to hash out my plan before I'm in too deep. I have a 30 gallon electric water heater that I want to install a heat pump onto. Step one will be to move the cold water intake to a tee located at the drain valve. The old cold water intake at the top will have the drop tube removed and a union fitting installed. This union will contain a plug with 2x 1/4 acr copper lines brazed in, continuing to a 25' coil on the tank. Midway the lines will terminate into a 1/2" copper stub which will be crimped around the lines and brazed to make a 180* turn tight enough to fish down through the 3/4 inlet. The heat pump will be a 5k btu R410a unit with original compressor and evaporator. Cap tube replaced with an R22 1/2 ton TXV and running propane for refrigerant. Heat pump will be controlled by a normal water heater thermostat through a 5 minute industrial power on delay timer to prevent any short cycling. Original elements will remain intact and wired up. Beaker off unless the backup is needed. Solid plan? Flaws?

07-11-16, 07:53 AM	#1
STM Helper EcoRenovator Join Date: Jul 2016 Location: Mississippi Posts: 35 Thanks: 19 Thanked 2 Times in 2 Posts	Heat pump water heater reality check Criticize me here. Want to hash out my plan before I'm in too deep. I have a 30 gallon electric water heater that I want to install a heat pump onto. Step one will be to move the cold water intake to a tee located at the drain valve. The old cold water intake at the top will have the drop tube removed and a union fitting installed. This union will contain a plug with 2x 1/4 acr copper lines brazed in, continuing to a 25' coil on the tank. Midway the lines will terminate into a 1/2" copper stub which will be crimped around the lines and brazed to make a 180* turn tight enough to fish down through the 3/4 inlet. The heat pump will be a 5k btu R410a unit with original compressor and evaporator. Cap tube replaced with an R22 1/2 ton TXV and running propane for refrigerant. Heat pump will be controlled by a normal water heater thermostat through a 5 minute industrial power on delay timer to prevent any short cycling. Original elements will remain intact and wired up. Beaker off unless the backup is needed. Solid plan? Flaws?