TheOverThinker
Member
I'm reactivating a 1980's era solar thermal system that's been out of service for about 15-20 years.
It's all working now, but I have a concern.
The potable water solar loop has two 100 gallon tanks. The tank hot goes via 1" pipe to meet the 2" cold feed to the 120 gallon commercial gas water heater. My concern is that if I isolate the water heater from cold, all 11 units of the apartment share the same 1" pipe through the solar system.
If I don't isolate the 2" cold feed then not much water will flow through the storage tanks.
The 2" main is centered in the photo.
The first 1" vertical pressurizes the storage tanks.
The second insulated 1" is the warm return from the top of the storage tanks:
The red ball valve closes the 2" cold feed to the water heater, forcing everything through the storage tanks.
The building has no backflow check valve to the main.
The building has 4 stories and 11 apartments.
Your thoughts?
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Note: the system died due to biofilm buildup in the Grundfos pump and/or failed Sunspool heat motor.
It's all working now, but I have a concern.
The potable water solar loop has two 100 gallon tanks. The tank hot goes via 1" pipe to meet the 2" cold feed to the 120 gallon commercial gas water heater. My concern is that if I isolate the water heater from cold, all 11 units of the apartment share the same 1" pipe through the solar system.
If I don't isolate the 2" cold feed then not much water will flow through the storage tanks.
The 2" main is centered in the photo.
The first 1" vertical pressurizes the storage tanks.
The second insulated 1" is the warm return from the top of the storage tanks:
The red ball valve closes the 2" cold feed to the water heater, forcing everything through the storage tanks.
The building has no backflow check valve to the main.
The building has 4 stories and 11 apartments.
Your thoughts?
--------------------------------------
Note: the system died due to biofilm buildup in the Grundfos pump and/or failed Sunspool heat motor.