Domestic Hot Water Secondary Circulation
Domestic Hot Water Secondary Circulation
(OP)
Hi,
I am a graduate mechanical engineer and would appreciate if someone could offer an explanation on the design of a DHW secondary circulation system.
I initially designed my system so that the pump on the return hot water pipe would pump towards the hot water calorifier. I have been told since that this is incorrect and that the circulating pump should be pumping in the opposite direction. Also, a non-return valve should be fitted on the return pipe before the circulating pump to prevent flow back to the calorifier. Does anyone have an explanation on why this is the case or even point me towards some information that is available on the design of a DHW secondary circulating systems.
Thank you
I am a graduate mechanical engineer and would appreciate if someone could offer an explanation on the design of a DHW secondary circulation system.
I initially designed my system so that the pump on the return hot water pipe would pump towards the hot water calorifier. I have been told since that this is incorrect and that the circulating pump should be pumping in the opposite direction. Also, a non-return valve should be fitted on the return pipe before the circulating pump to prevent flow back to the calorifier. Does anyone have an explanation on why this is the case or even point me towards some information that is available on the design of a DHW secondary circulating systems.
Thank you





RE: Domestic Hot Water Secondary Circulation
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RE: Domestic Hot Water Secondary Circulation
My question is where exactly should I position the circulating pump?
I have been told that the pump should be positioned on the return pipe and circulation should be from the return to the flow pipe. This would be opposite the flow of hot water. The explanation that I have been given for this set up is that when a tap is opened it will gain maximum flow both from the flow and the return pipe. If the pump circulate from flow to return then a portion of the flow will always circulate this way when a tap is opened. Thus, potentially reduced flow to the tap.
Is this a correct?
RE: Domestic Hot Water Secondary Circulation
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RE: Domestic Hot Water Secondary Circulation
It does not make sense to have opposite flow in a pipe as this creates noise, vibration and frition losses.
The direction should be towards the calorifier if installed in the return pipe.
RE: Domestic Hot Water Secondary Circulation
Thx.
RE: Domestic Hot Water Secondary Circulation
RE: Domestic Hot Water Secondary Circulation
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RE: Domestic Hot Water Secondary Circulation
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