Hydronic Floor pump frequency vs water supply temp?

compman723 · 11-13-12, 06:00 PM

I am in the beginning stages of designing an hydronic in floor setup for our main level. I always hear that the lower the supply temp the better the efficiency, but what I take from this the pump has to run longer times than correct? What I am thinking is that instead of having 90 degree water and the pump running half the time wouldn't it be more efficient to have the pump run for shorter periods with water at a higher temp?

For this discussion I would like to take away the energy loss from heating the water 120 degree vs 90, reason is my hot water source is already producing water at 140 about so it really is no difference.

So summarized I am wondering why it would be so bad to put 140 degree water into floor at a flow rate to get a delta t of 15 degrees with less frequency needed vs a lower water temp.

Thanks everyone for your input!

11-13-12, 06:00 PM	#1
compman723 Lurking Renovator Join Date: Oct 2012 Location: MSP Posts: 6 Thanks: 2 Thanked 0 Times in 0 Posts	Hydronic Floor pump frequency vs water supply temp? I am in the beginning stages of designing an hydronic in floor setup for our main level. I always hear that the lower the supply temp the better the efficiency, but what I take from this the pump has to run longer times than correct? What I am thinking is that instead of having 90 degree water and the pump running half the time wouldn't it be more efficient to have the pump run for shorter periods with water at a higher temp? For this discussion I would like to take away the energy loss from heating the water 120 degree vs 90, reason is my hot water source is already producing water at 140 about so it really is no difference. So summarized I am wondering why it would be so bad to put 140 degree water into floor at a flow rate to get a delta t of 15 degrees with less frequency needed vs a lower water temp. Thanks everyone for your input!