Hi all,
I know the word overspec is always a bad one but bear with me.....
I have 3 bar pressure at the garden tap and roughly 13-14L /min at the kitchen tap. At 1 bar I have around 111/12L /min.
Considering a combi and the flow rates stated are for 35/40degree rises all advice I have seen is to go for a combi (if I do pick one) that supplies this rate.
The thermostatic shower I want to use states minimum hot of 52 degrees which in summer will be ok but in winter could be some way off and need higher temperature rise and lower flow.
So.........
My questions are 2...
1) When a combi says that x l/min hot water rise by 40 degrees I am guessing the total output flow will increase that figure at the tap as cold will need to be added to hot water? Temperatures dependent of course but flow should increase when you add cold no?
If so....
2) Based on the calculation for winter that for example 12l/min rising by 50 degrees would need 42kw output (far in excess of advice for current flow rate boiler size) I calculate that 42kw would provide this. Based on 12/60 x 50 x 4.2 joules = 42kw.
Although 42kw is incredibly overspecced, would it not mean that my puny 13/14l coming in would all be 50-60 degrees? Hence no flow drop required in winter?
Theoretical this is .........
I know the word overspec is always a bad one but bear with me.....
I have 3 bar pressure at the garden tap and roughly 13-14L /min at the kitchen tap. At 1 bar I have around 111/12L /min.
Considering a combi and the flow rates stated are for 35/40degree rises all advice I have seen is to go for a combi (if I do pick one) that supplies this rate.
The thermostatic shower I want to use states minimum hot of 52 degrees which in summer will be ok but in winter could be some way off and need higher temperature rise and lower flow.
So.........
My questions are 2...
1) When a combi says that x l/min hot water rise by 40 degrees I am guessing the total output flow will increase that figure at the tap as cold will need to be added to hot water? Temperatures dependent of course but flow should increase when you add cold no?
If so....
2) Based on the calculation for winter that for example 12l/min rising by 50 degrees would need 42kw output (far in excess of advice for current flow rate boiler size) I calculate that 42kw would provide this. Based on 12/60 x 50 x 4.2 joules = 42kw.
Although 42kw is incredibly overspecced, would it not mean that my puny 13/14l coming in would all be 50-60 degrees? Hence no flow drop required in winter?
Theoretical this is .........