Ask the Question

Alan Whitmore · Joined: 01 Jul 2003 Posts: 3

I am in the process of completing a barn conversion which involves adding 11 more radiators to my existing 11 radiator system. My boiler has the capacity for the additional radiators (120000 btu) and I would like some guidance on the type of circulation pump to install. I currently have a standard domestic pump which should typically be used with a maximum 12 radiator system.

AlanE · Posted: Tue Jul 01, 2003 1:11 pm Post subject:

Can you give idea of boiler make/model (internal or external pump), sealed or openvented and how many floors?

Presumably the existing rads are in one building at present. Will the barn conversion effectivly enlarge this property of will it be considered as a seperate entity (even if joined to it)? Reason being suggestions regarding best way of controlling system as a whole.

Alan

Alan Whitmore · Joined: 01 Jul 2003 Posts: 3

The boiler is a Ferroli GN1 03, the system is a sealed system and the additional radiators are on the ground floor which is the same as the boiler. The property will become one residence with a link building between the barn and the existing house. I should add that the boiler is sited in the barn which is being converted and already has the necessary bulkheads for feed and return of the additional radiators.

Alan W

thescruff · Moderator Joined: 03 May 2003 Posts: 4758 Location: Bath

To work out the correct size pump you would need to know the system design, pipe sizes, runs etc.

I would consider at least the Grundfos UPS25/55, you may be better splitting into two zones with a 15/60 on each.

thescruff. Cool

AlanE · Posted: Tue Jul 01, 2003 6:19 pm Post subject:

Alan the reason I asked if it would effectivly a single property or two seperate was to suggest seperate zones, each controlled by motorised valve and room stats.

As you say that it will be two buildings with a connecting it might well be worth considering.

You MUST however take account with such a large sealed system is that any internal, to boiler, expansion vessle, will not be sufficient. An extra one will be required.

Alan

Alan Whitmore · Joined: 01 Jul 2003 Posts: 3

Many thanks for the advice, I shall now investigate the requirements for a "zoned" system with the intention of completing the installation myself.

Best Regards

Alan

AlanE · Posted: Wed Jul 02, 2003 1:07 pm Post subject:

With a system as large as you are contemplating I would honestly reccomend that you find a company local to you willing to design the system properly.

You need to make serious consideration to expansion vessle size, pump size and pipe sizes if the system is to work properly.

An average standard domestic system can be virtually thrown together on a whim, may not work very effeciently but it will be reasonably safe. A system with a large number of rads really need designing properly in order for it to be safe.

Water in a sealed system needs somewhere to go when it expands. If the expansion vessle is of insufficient size the expanded water still needs somewhere to go. If it can't go into a specially designed vessle it will make alternative arrangements. Normally with quite explosive results.

Alan

thescruff · Moderator Joined: 03 May 2003 Posts: 4758 Location: Bath

And I agree with Alans comments wholeheartedly, As an experienced fitter in the larger market to avoid system noise and an even distribution of heat careful planning is needed.

thescruff. Cool