Expansion vessel size large system

[slide]

Have seen many differing formulas for this.

My system volume is 1417 litres
My static head is 11 metres
PRV set at three bar

One calculation I found said it should be 145 litres... can you imagine?
Another said 50, which seems more realistic!

Cheers

 

[happyflyer]

That one hell of a system over 300 gallons, how big are the boilers

 

[newcastle phill]

Wow thats one mutha of a system.
Almost 1.5 tonne of water...

Whats it in......2 bed semi

 

[happyflyer]

http://www.bssindustrial.co.uk/uploads/docs/589.pdf

Its a two up and two down office block

 

[Ermintrude]

150 sounds reasonable

 

[slide]

Total 92kW. Cast iron/column rads.....

 

[Ermintrude]

So 150l then . Some expansion going to occur don't want the gaskets flexing on the groundfloor cos plant rooms on roof and fitted with 12l vessel?

 

[newcastle phill]

http://www.bssindustrial.co.uk/uploads/docs/589.pdf

Its a two up and two down office block

Now it makes sense

 

[Ermintrude]

That one hell of a system over 300 gallons, how big are the boilers

Cdi classic 24kw

 

[bright spark]

A rule of thumb from an expansion vessel/pressurisation unit pump supplier I was told to go by if your stuck on a Commercial job is 1 litre per kW once it's not a high temp heating system. Then go up to d next size up. In your case 100litres.
Should do ye. Did I read ye have d system pressure is set at 3 bar. Maybe I read it wrong, that's a bit too high for 2 storey block. 1.5 bar should be plenty