Hot water performance

[steve26]

Can anyone tell me how 'constant flow' works on an indirect unvented hot water cylinder. Many manufacturers have litres per hour figures in their literature and then reheat times in the same table.

Do it mean the indirect cylinder can produce so many 'litres per hour' based on a certain boiler input?

Cheers

 

[cider]

Can anyone tell me how 'constant flow' works on an indirect unvented hot water cylinder. Many manufacturers have litres per hour figures in their literature and then reheat times in the same table.

Do it mean the indirect cylinder can produce so many 'litres per hour' based on a certain boiler input?

Cheers

basically the cylinder will have a reheat time from cold.
imagine 180 litre tank cold, boiler starts and heats tank in 30 minutes.
therefore tank can produce 360litres hot water in 1 hour.
boiler input not important in hw only mode as coil in cylinder has low requirement compared to most boiler outputs

 

[mickyg]

steve, I'm assuming you are gathering information in regards to your commercial installation project. I think you are going to in depth trying to get an accurate solution for your needs. So I recommended you get about 600litres of unvented hot water store(2x300l with immersion back up, in series), heated by your current boiler and I'm sure everything will be hunky dory

 

[steve26]

steve, I'm assuming you are gathering information in regards to your commercial installation project. I think you are going to in depth trying to get an accurate solution for your needs. So I recommended you get about 600litres of unvented hot water store(2x300l with immersion back up, in series), heated by your current boiler and I'm sure everything will be hunky dory

Yes, thats right, just trying to investigate further! I am thinking about the ACV tanks which apparently have a quicker re-heat time due to their tank-in-tank system, instead of the standard coil. The ceiling heights are around 2.15m, therefore I am looking at 2no. 240's, at 1.65m high they will fit better than 2 no. 300's as they are around 1.95m high. I hope 480litres will be enough?? I suppose the slightly small tanks would re-heat quicker, so it may be a better solution?

I am unsure whether to get the versions which have the immersions, apparently they would take upto 7 hours to heat a 240 cylinder?