I work at a local college of further education and have a query/question regarding drinking fountains.
We have boosted hot and cold water systems for washing hands, showers, flushing toilets etc. The mains incoming cold water is held in storage in two x 5,000 litre, insulated tanks and all pipework is thickly insulated throughout the full run, (we believe). The mean temperature of both tanks is usually around 13 - 15C at this time of year and maybe 17-19C during hot summer weather). All hot runs have a return leg just before each tap outlet so there is almost instant hot water when taps are turned on. Incoming hot is around 55C and incoming cold is same as tank temperature before being mixed through a TMV to give an output of around 39-41C
We have 7 drinking fountains, (strictly bottle/cup fill and no mouth contact allowed). Temperature checks on these first thing of a morning, (8.00am), usually come in at around 21-22C but drop below the regulation 20C within 2 minutes as required by law. However, we have one on the second floor outside the changing rooms/showers which persistently reads around 26-28C and takes at least 1 hour to drop below 20C
I'm not a plumber but the only scenarios I can think of are;
a/ There is a section of pipework in the area of the changing room/showers which are un-insulated and close together thereby causing heat transfer from the hot pipework. But this doesn't explain why it takes so long to come down to temperature if the main feed is in the ceiling above. (About 6'-7' higher than outlet).
b/ There is a wrongly connected TMV in that area which is allowing some hot to cross into the cold. (We have approximately 110 TMV's throughout the building serving various wash basins/showers etc but if this is the case, then surely the temperature wouldn't come down at all?
I've tested the local TMV's by turning off the 'cold' side and they all prevent the 'hot' side from flowing, which is the expected outcome. Now the only other thing I can think of doing is checking the hidden pipe runs are fully insulated, (mostly behind a suspended ceiling thankfully), and taking test readings to see if there is a discrepancy at any point(s).
Can anyone think of any other things I should be trying that I haven't thought of?
We have boosted hot and cold water systems for washing hands, showers, flushing toilets etc. The mains incoming cold water is held in storage in two x 5,000 litre, insulated tanks and all pipework is thickly insulated throughout the full run, (we believe). The mean temperature of both tanks is usually around 13 - 15C at this time of year and maybe 17-19C during hot summer weather). All hot runs have a return leg just before each tap outlet so there is almost instant hot water when taps are turned on. Incoming hot is around 55C and incoming cold is same as tank temperature before being mixed through a TMV to give an output of around 39-41C
We have 7 drinking fountains, (strictly bottle/cup fill and no mouth contact allowed). Temperature checks on these first thing of a morning, (8.00am), usually come in at around 21-22C but drop below the regulation 20C within 2 minutes as required by law. However, we have one on the second floor outside the changing rooms/showers which persistently reads around 26-28C and takes at least 1 hour to drop below 20C
I'm not a plumber but the only scenarios I can think of are;
a/ There is a section of pipework in the area of the changing room/showers which are un-insulated and close together thereby causing heat transfer from the hot pipework. But this doesn't explain why it takes so long to come down to temperature if the main feed is in the ceiling above. (About 6'-7' higher than outlet).
b/ There is a wrongly connected TMV in that area which is allowing some hot to cross into the cold. (We have approximately 110 TMV's throughout the building serving various wash basins/showers etc but if this is the case, then surely the temperature wouldn't come down at all?
I've tested the local TMV's by turning off the 'cold' side and they all prevent the 'hot' side from flowing, which is the expected outcome. Now the only other thing I can think of doing is checking the hidden pipe runs are fully insulated, (mostly behind a suspended ceiling thankfully), and taking test readings to see if there is a discrepancy at any point(s).
Can anyone think of any other things I should be trying that I haven't thought of?
