AD7
New Member
Hello Everyone,
I work for an energy efficiency retrofit company and have a project that uses hydronic heating system with 5 zones. The zones have circulators (dry rotor) on the return side of the boiler, and the it was designed (ages back) this way to allow the pumps to operate with cooler return water. It's believed that lower water temps prolonged the life of the packing, seal, and motor.
One of my concerns is the placement of the expansion tank which creates issues in system pressurization. The picture attached
shows the schematics of the system. The irregular placement of the expansion tank causes problems in the system with air entering the system and the circulator likely to cavitate. I would like to receive feedback on the following issues:
I work for an energy efficiency retrofit company and have a project that uses hydronic heating system with 5 zones. The zones have circulators (dry rotor) on the return side of the boiler, and the it was designed (ages back) this way to allow the pumps to operate with cooler return water. It's believed that lower water temps prolonged the life of the packing, seal, and motor.
One of my concerns is the placement of the expansion tank which creates issues in system pressurization. The picture attached
shows the schematics of the system. The irregular placement of the expansion tank causes problems in the system with air entering the system and the circulator likely to cavitate. I would like to receive feedback on the following issues:
- The current system might create some locations that have subatmospheric pressure when circulator is on. We have put bleeding valves on all radiators to address the situation. Is their a way to avoid this?
- The placement of the expansion tank isn't ideal, and i would like to know what would the best placement of the expansion tank? Ideally an expansion tank should be placed before the circulator, however we have 5 zone circulators and placing the expansion tank before them doesn't work out.
- I thought about redesigning the system, and placing the circulators on the supply side but the work is construction heavy and with old piping issues crop up that're unforeseen. Any suggestions?