14 ensuite rooms, 3 x 300 litre unvented cylinder's, BOILERS ????

[hickings]

hi, I have been asked to finish a guest house which has 14 unsuite shower rooms. the old builders and plumbers have been kicked off for being too slow. the owner just wants it all finished now.
there is a 28mm hot feed, 22mm secondary return and a 22mm cold all already go to each room which I have pressure tested already. the incoming mans is a 50mm feed.
there will be just four radiators in communal areas.
all rooms will have air conditioning for heating/cooling.
they want 3x300 unvented cylinders which I will have no problem linking up.

PROBLEM
they want 2x 24kw Worcester Greenstar 24i System Boiler, with a low loss header.
i understand the owner wants two boilers linked together one for back up.

my issue is i think they are over kill for 3 cylinders and 4 rads

is there a better way to link the two boilers without using a low loss header and without multiply pumps as there is not much heat output needed. its not a cost thing.
i just wanted to here anyone else's suggestions?

 

[Killy Bing]

If they want it and are willing to pay, whats the problem?

what are the cylinders?

if they were oso super series each one would pack a 24kw coil!!

 

[TBServices]

14 bathrooms will deplete the cylinders in no time, so you ideally want the full KW allowance to aid fast recovery.

 

[Howsie]

28mm don't sound big enough to me but then again I'm full of morphine at the moment

 

[Roger Welton]

28mm deff doesn't sound big enough, and I'd be looking at Andrews type water heaters for such a large demand, 14 guests all getting up in the morning at roughly the same time put some load on the system.

 

[hickings]

I agree 28mm don't seem enough for me i am optimistic, I would of preferred to re design the whole layout but with plastered walls and already spending £350,000 on old builders he wants to make this work.
I was going to fit 3 x megaflo,
thanks for the reply, I suppose it would worth doing just for the fast recovery.

 

[Roger Welton]

2 x 24kW won't equal quick recovery on 3 x 300l Megaflows IIRC the coils can absorb 20+kW each

 

[hickings]

What would you fit Roger?????

 

[Roger Welton]

Andrews water heaters

Andrews Water Heaters and renewable heating solutions

They have a nice sizing app on the site somewhere

 

[IDCHAPPY]

28mm don't sound big enough to me but then again I'm full of morphine at the moment

Pass some here

 

[Dotty]

Andrews water heaters

Andrews Water Heaters and renewable heating solutions

They have a nice sizing app on the site somewhere

I agree, I've just commissioned an ecoflo 380/980. A nice bit of kit with recovery rate from cold of about 15-20 minutes.

 

[Ermintrude]

I would in the face of others suggest two Jumbo 800 ACV of course. LLH means that alternate low density heat can be figured in, bio mass ect. With all those bathrooms I would be suggesting waste water heat recovery - uses heat left in drains to heat cold incomming 10c is a massive saving in 1600l.

Also with LLH means that the cylinders can be used one at a time or both when fully occupied. 4 rads can be dragged of LLH. Wouldn't use wb pap. Ur gonna need some beef!

 

[Killy Bing]

I would in the face of others suggest two Jumbo 800 ACV of course. LLH means that alternate low density heat can be figured in, bio mass ect. With all those bathrooms I would be suggesting waste water heat recovery - uses heat left in drains to heat cold incomming 10c is a massive saving in 1600l.

Also with LLH means that the cylinders can be used one at a time or both when fully occupied. 4 rads can be dragged of LLH. Wouldn't use wb pap. Ur gonna need some beef!

Pair of intergas 36/40's running the two nearest en suites each.....

 

[Ermintrude]

Wouldn't like to comment on intergas as never touched one. Vogue 40c probably for me if I was going down combi route? Prefer 3 no logic 30 systems

 

[Howsie]

Sit down and do your calcs for the heating, hot water, loading units/pipe sizing and tell them what they should have in place to cater for such an installation.

This will highlight the gap between what's been installed versus what should have been installed.

It sound like a small domestic plumber had had a go at this and was clearly out off his depth.

Tip: Don't let his problems become yours.