megaflo 300litre?

[chs]

Hi,
Im currently doing up a 3 story guest house.
the owner is making into flats for students and is puttin 8 en-suites in it. theres no baths going in, just showers and basin, and obviously w.c's. what would you recommend to be the best system to put in?
i was thinking of a 300litre megaflo cylinder and a baxi megaflo 35kw boiler with each floor zoned off for the heating. theres 21 radiators in total.
i have suggested to him upgrading the mains as this is currently in lead which looks the size of 22mm which will make the internal bore probably about 15mm which wont be enough pressure for the megaflo cylinder never mind feeding upstairs showers and basins.

Whats your opinions?

 

[simond]

I'm hoping you are not a heating technician employed for this job, because you shouldn't have to ask these questions.

I'm also hoping you are not going to take the customer's money and design their system using opinion on a web forum, where you have no idea which posters have;

(a) the experience
(b) the training
(c) a big mouth

NB: Some have all three. (c) will be most certain though, if you want a firm decision.

 

[muggles]

Pressure has nothing at all to do with the size of the supply pipe (well, it does, but not in the way you think it does). Other than that, ditto what Simon said

 

[Dan Robinson]

There are plenty of ideas on this sort of thing in the combustion chamber .

 

[dcawkwell]

With 8 flats must be stuffing them in tight. 8 flats relying on the system I would suggest two boiler system in cascade. 8 showers working on say have 4 running at once would require
40 litre flow rate. You haven't specified what pressure you are actually
getting so upgrading the supply pipe might not get you anywhere if
you have poor dynamic pressure you'd need to be looking
at a cold water accumulator.
Personally I would use two unvented cylinders rather
than one bigger one
4 showers running at once is likely to exhaust the a 300 litre cylinder
in 10 minutes.
Perhaps take a look at tank in a tank cylinders that have very fast reheat times.

 

[gaswizzard]

Whatever happened to the tried and trusted 36x18s.

 

[swbjackson]

I think everyone's missing the point here. It's student accommodation and as students never wash a 24Kw combi will fit the bill.

 

[Dan Robinson]

I was about to suggest a couple of 24 Juniors, or Lamborghini's?

 

[Agile]

4 showers running at once is likely to exhaust the a 300 litre cylinder
in 10 minutes.

I would have thought a daily 10 minute shower should be fine!

When I was a student all we were allowed was a bath filled to 4" once a week. Although we used to get away with 5" or 6" as no one was checking!

Customer today admitted he often had 45 minute showers.

Tony

 

[Agile]

I suspect that a quoted coil heat transfer will be rated at the highest figure which is when the water inside is starting out cold.

This will reduce as the water warms up.

There is often a lot of diversity between shower usage. Some shower in the morning and others in the evening and some hardly at all!

Tony