How much space required for this plant room?

[doitall]

with low flows ie one shower at 10l/m a 70kw boiler reheating through a 70 kw coil would cycle...


Not if it had two smaller boilers it wouldn't.

And a 70Kw boiler is plain crazy, the only time you'll need half of that is if/when 3-4 showers are used at the same time,

I agree, but you need a compensation controller that handles boilers under35 kws

So thats not outside your skills, you could even chuck in weather compensation for good measure.

 

[gaswizzard]

how come?

Its all physics at the end if the day..nothing to be off the mark about...

Your 'physics' aren't quite right Alec , maybe these 'physics' would be nearer the mark?

shc x kg x K x 100/kw x efficiency.

 

[doitall]

Size of boiler would depend on recovery rate , considering the OP wants two 10 litre showers running at the same time along with a bath and washing up to run consecutively then 70 kw wouldn't be overkill.

We can only give answers based on the info given.

But we haven't been given that information GW

2 x 210Ltr cylinders should be more than enough, especially when you consider the whole cylinders will be hot thanks to the secondary return.

One could always bump the temperature up if they wanted more hot at any time.

 

[gaswizzard]

Size of boiler would depend on recovery rate , considering the OP wants two 10 litre showers running at the same time along with a bath and washing up to run consecutively then 70 kw wouldn't be overkill.

We can only give answers based on the info given.

But we haven't been given that information GW

The OP gave the above info earlier on in this thread

2 x 210Ltr cylinders should be more than enough, especially when you consider the whole cylinders will be hot thanks to the secondary return.

Considering the info above what size boiler/s would you spec? (recovery rate)

 

[doitall]

I would double the existing WB 30CDi, under sufferance.

From choice I would go for two small Atags, around the 35-40Kw mark, with a brain in one, or possibly the madQ

 

[mickyg]

he only wants to know how much room he needs, not you lot spunking over your favourite equipment
we dont even know the heat requirements, wast of time, but im sure your enjoying yourself

 

[indus]

Thanks guys, so much useful information.

To be clear though I would need two showers to run for 15-20 minutes at the same time.

A sink should also be able to be run at the same time (ie to wash up/wash your face/have a shave)

The system needs to be able to cope with this day in day out.

The showers should be ready to give another 2x 20 minute sessions quite soon.

This is about maximum (but regular usage), five showers will never be run at the same time.

Please also remember that there are 30 odd rads to be run, I presume this needs to be taken into account when it comes to boiler capability?


Thanks again for all the great advice

 

[gaswizzard]

I calculated a 40 minute recovery rate (70kw) for the 500 litre cylinder , seems about right if the OP is using 300 litres for a 15 minute shower plus a bath and some water for washing up , obviously the 70 kw may be a tad oversized for the heating requirements but that wasn't what the thread was about.

Where is the OP?

EDIT , sorry OP you are here.

 

[doitall]

he only wants to know how much room he needs, not you lot spunking over your favourite equipment
we dont even know the heat requirements, wast of time, but im sure your enjoying yourself

Trip down memory lane for me Micky

As said, you need to sit down with the client and discuss the options, then you can design the system, and only then can you say for certain how much space you need.

Perhaps the Op should invite a couple of the guys round to do just that, preferable on different day.

 

[Agile]

70 kW ? Perhaps I have missed something in this race to overspec.

Once the two showers and two baths have been taken, I cannot see any need for significant further hot water for at least four and probably at least eight hours.

If that is the case then all that is required is a boiler or two of a total of say 28 kW to reheat within those timescales.

Or is the objective to fleece the OP with a much more expensive system than is needed?

Tony

 

[Dan Robinson]

Although the OP here is more sensible and reactive than most I suspect he hasn't considered his diversity properly.

I tend to agree with John on the cylinders - but would go for two Atmos Intersystem HE26 with the Cascade PCB's. compensation can be added for additional spunk factor if needed.

MM's idea of a twin coil can be utilised almost as efficiently with the appropriate controls, but two separate cylinders would keep the primary return temps lower for longer.

You could be really smart an install two Atmos InerCombi HE32's and run the utility and kitchen services off the combi side of things and not have to factor them into the peak load calcs .

How's about them apples

 

[gaswizzard]

Or is the objective to fleece the OP with a much more expensive system than is needed?

Tony

No certainly not , but if the OP is happy to wait 90 minutes for the 420 litre/28kw tanks to recover then fine , 28 kw it is.

 

[Agile]

Or is the objective to fleece the OP with a much more expensive system than is needed?

Tony

No certainly not , but if the OP is happy to wait 90 minutes for the 420 litre/28kw tanks to recover then fine , 28 kw it is.

Just how many people have a bath/shower every 90 minutes?

 

[gaswizzard]

Just how many people have a bath/shower every 90 minutes?

Funny you should ask Tony.

My house has a 300 litre megaflow with a 23 kw boiler (75 odd minutes recovery) , at 6 pm the daughter has her shower for 30 minutes (8" watering can head) , then the nephew has his shower , then I have to wait for the water to heat up before I have my bath (200 litres used) along the wife washing up , then the wife has to wait another 60 minutes or so for the tank to heat.

That 500 litre/70kw would do the job nicely.

 

[Agile]

Wow!

Its no wonder there is a water shortage!

I suppose you dont have a water meter?

When I was a student you were allowed a bath once a week on your assigned day and only 4" deep! But the landlady did not check the depth so I had 5" !