What is a high recovery cylinder and is this one?

[Paul205]

People,

I am soon going to be getting a Gledhill stainless steel hot water cylinder fitted by my plumber. This is viewable at the following link

http://www.gledhill.net/pdf/Spec 107-06 EnviroFoam Stainless.pdf

I shall probably be opting for the 48 x 18 item.

Can anyone please advise what a 'high recovery cylinder`is and also if the Gledhill is a 'high recovery cylinder?

Many Thanks




Paul

 

[Agile]

20-30 years ago some cylinders were made with oversized heating coils, usually formed from several loops of smaller tube and were sold for people who wanted faster reheat times.

Since then the requirement for reheat times have been shortened in order to make them operate more efficiently.

So standard cylinders now reheat in about the same time as the old faster ones.

Tony

 

[Onetap]

There is a British Standard for domestic indirect hot water cylinders. This specifies, amongst other things, the minimum surface area of the coil, within the cylinder, which heats the stored hot water.

A cylinder with a larger coil surface area will have more copper tube in it, will cost more and will reheat faster, hence fast recovery. It would be worth checking the BS to see what area of coil you get in a standard cylinder and how much more you'd get in those sold as fast recovery ones.

In the olde days, before the current BS was published, the cheapest cylinders available had a 'short coil'. These cost slightly less (less copper) but would cost the customer more in running costs. The customer usually wasn't aware of the difference and they usually got a short coil. It's usually cost-effective to replace a very old cylinder, even if it doesn't leak.

 

[ALEC1]

thats not entirel fair 1 tap...boilers needed higher return temperatures to avoid condensation....so the coil was smaller

 

[Agile]

Thats not al all fair either Alex!

A boiler with a flow temp of 80 C would need a hell of a coil to absorb so much heat that the return would be at 55 C to make it condense!

Typically a cylinder will have a flow/return diff of about 10C unless the flow is slowed to increase to better suit condensing boilers.

Tony

 

[gaswizzard]

thats not entirel fair 1 tap...boilers needed higher return temperatures to avoid condensation....so the coil was smaller

 

[mickyg]

thats not entirel fair 1 tap...boilers needed higher return temperatures to avoid condensation....so the coil was smaller

thats class

 

[africanplumber]

to make the cylinder higher recovery i put some bricks under it to raise it, the more brick the higher the recovery its easy