1 immersion heater or 2 ???

[malc]

Hi all, just renovating a small flat for a customer, installing bathroom to include bath and basin ( electric shower )
and kitchen sink.
was thinking of putting in a 450 x 900 hot water cylinder, with a 25 gallon cwsc above.
do you think i need 2 immersion heaters, or will 1 give enough hot water ?

thanks in advance for any suggestions, malc.

 

[stevetheplumber]

bottom entry best

 

[kay-jay]

the thinking behind two immersions is one fitted low to heat the whole tank and a higher one to heat top third only as a boost

 

[Best]

Top one would be handy when only smaller amount of hot water needed & it would be slightly quicker & more efficent as it is not putting heat from the lower position in the side of cylinder going up through more cold water.
Better to have 2 heaters in case one fails, so they have a backup. Also would be faster heat up if both heaters on at same time.

 

[hammers4spanner]

top one is a booster as alreadsy stated

 

[heliotrope]

If it is going to be a direct cylinder then you should be fitting two immersions.

The bottom one would be fitted on a timer to take advantage of off peak night
electricity rates.

The top one would only be switched on for a top up if required.

If the cylinder is heated indirectly, say from a boiler then just the normal 27"
immersion would be adequate as this would normally only be used in case of
boiler break down.

 

[malc]

thanks for replys, i should add that there is no cheap night tariff available.
so would 1 immersion in the top of the cylinder be ok ?

 

[Best]

thanks for replys, i should add that there is no cheap night tariff available.
so would 1 immersion in the top of the cylinder be ok ?

Depends on type of heating in flat & what the customer wants to pay for.
If it is electric heating in flat, then 2 electric immersions would be much better, though a single 27" element would do, but doesn't have any backup or no flexibility that 2 would give.
If gas heating, then if customer happy, any single element (side or larger top 27") will do as a back up.
It's the extra cost of wasting electricity that the customer should consider if just having one element.

 

[migoplumber]

if the cylinder is relatively new and well insulated, shouldnt really make a difference. on the data plate it will tell you the heat losses.
using 2 elements would give you a lower reheat time if clients are bathing one after another. and also provides the backup if one fails.
it wouldnt use twice as much lecky as it would take half the time to heat up. the heat losses will still be the same.
find out what the customer habits are in the bathroom and fit one or two to suit.

 

[PETE 123]

What about a fortic cylinder ?

 

[malc]

Thanks for all the replies guys.
My preference is to fit 2 immersions as suggested, but having trouble locating a cylinder with 2 immersion bosses from my usual suppliers, ( any suggestions )
if not then i`ll just fit a 27" in the top.
thanks again,malc

 

[heliotrope]

If it is a direct cylinder you are looking for then there should be no problem
getting one with two immersion bosses.

You can use an indirect with 27" immersion and no need to connect primaries.

 

[jam1979]

ask them if they want a nice little megaflow direct unvented cylinder if they have the space providing they have the right incoming pressure