How do I know if cylinder can cope with shower ?

[Piperdave22]

Looking to fit an Aqualisa visage shower they say a 50 gallon cold water storage cylinder is minimum but don’t give a figure for the hot water .
How would I work out if the hot water cylinder size would be adequate ?

 

[Aire]

From memory, the visage will deliver around 12 litres per min. Depending on temperature, you will use around 7 - 8 litres of hot water a min so a standard 900x450 cylinder will deplete it's hot water in around 12 - 15 mins of use.

 

[Piperdave22]

Hi Craig, thanks for your reply , is there a somewhere I can find the formula for this regarding l/min temperatures etc .
Manual says visage delivers 10l /min

 

[Aire]

Don't know about the manual. I'm just going off what technical told me when I rang them regarding a similar query. It's maybe 10ltm when switched to eco mode. The formula for hot water they didn't tell me, I just based it on a 60/40 split between got and cold.

 

[chris watkins]

There you go Piperdave hope the attached helps?
The problem is the incoming cold water temperature changes throughout the year so it will affect the amount of hot used. In winter it can be coming in from the mains at 4 or 5 degC in late summer it can be 14 - 15degC from a designers point of view we normally take it as 10 (so tc = 10)
An average showering temperature is 39 - 40 degC (so t = 39)
Stored hot water is normally held at 60 - 65 degC ( so th = 65)
If you know the final flow rate you could work out either hot or cold