Low loss header system design.

[solutions]

Anybody know a good source of information pertaining to best practice with a low loss header based heating system.
I am taking on my biggest single house install to date and much of the design of the system is new territory for me. The building is listed 3 storey with open fires in most of the rooms. There are 13 rooms in total inc kitchen bathrooms etc and a huge full height hall / atrium. The heat losses are massive and I will need to link 2 30KW boilers through the low loss header. I am putting a zone per floor and 250L unvented to supply the 2 main bathrooms ensuite cloak room and kitchen with secondary return as they are so spread out. I am interested to know if it is best to have each zone flow from and return to the llh or if I can take a single flow and return to a location away from the boilers were I can locate the zone valves and split in to the three sets of flow and return, with pipe sized accordingly for heat transmission and pressure loss of course. Also would appreciate opinions on using pumps instead of zone valves or is it better too use a single large pump with zone valves? I assume the deciding factor is a ballance between cost and reliability?

 

[Chalked]

I like to use zone valves.
it acts as a positive off for each zone, plus makes the boiler switching easier using the end switches.

 

[dancinplumba]

Will 250 be enough ?

 

[solutions]

Will 250 be enough ?

I questioned it myself while assessing the requirement although there are a total 2 baths and 3 showers there are only 4 bedrooms. Even if each were inhabited by an adult couple the max likely cylinder load I calculated would be approx 300L but with a < 30 min recovery time on the cylinder I think 250 should be adequate for most scenarios. If you think it is too small then I am open to your advice. Its not been purchased yet.

 

[Ermintrude]

Acv SL plus and a greenstar LLH it's good for 70kw and is only 150

 

[Ch4 plumbing]

Ermi what's the price of ACV? Compared to say Ultrasteel?

 

[Ermintrude]

25% more. But if it's a listed building I anticipate that they are not short of a bob or two. U could set up the SL plus as a blended header. With UFH or towel rails ? I like recovery and the fact they sit hotter so deliver more water than a standard boiler. With a heat load of 30kw you could just use a bit of 54mm as the header and 35mm primaries to boiler and then pumps and zv away from there?


Google says [DLMURL]http://www.thermsaver.co.uk/acv-smartline-sle300-indirect-stainless-unvented-cyl-kit-tmv.html[/DLMURL]

 

[Ch4 plumbing]

I know nothing about them, you use them a lot?

 

[Ermintrude]

Wouldn't say a alot but they are a premier product for every application and we spec them first and work down to a megaflow

 

[Ch4 plumbing]

Heat up time is quick!

In an ideal world they would be going in at every U/V job but that's a lot of dollar!

 

[Ermintrude]

It's a lot of shiZZLE TOO!

 

[solutions]

25% more. But if it's a listed building I anticipate that they are not short of a bob or two. U could set up the SL plus as a blended header. With UFH or towel rails ? I like recovery and the fact they sit hotter so deliver more water than a standard boiler. With a heat load of 30kw you could just use a bit of 54mm as the header and 35mm primaries to boiler and then pumps and zv away from there?


Google says [DLMURL]http://www.thermsaver.co.uk/acv-smartline-sle300-indirect-stainless-unvented-cyl-kit-tmv.html[/DLMURL]

Although the 2 linked boilers will be "30kw" there peak output each is actually around 27kw so LLH will be handling around 54kw. Despite what you would think the client does not have limitless budget. Property was bought at auction and is now being done up to sell on. I could throw any old carp in as I will be long gone before anyone cares if it really works or not but I would much rather the place got a quality functioning system for whoever ends up living with it. The heat losses for some of the rooms are massive, at least compared to what im used too, so sadly the flow and return temps are such that peak efficiency will be rarely achieved through the boilers condensing but without the high flow temperature the radiators get impossibly big too reach desired room temp. Its not an attractive property in my opinion and its layout is awful and little to no garden it would be better off demolished I cant see why it should be listed other than its age and its location on the town highstreet / market square.

 

[Ermintrude]

54mm 1200 long .

 

[solutions]

54mm 1200 long .

No need to brag!

 

[Ermintrude]

Thought that said.... No need it's borag

 

[solutions]

Anyone know of a low loss header manu in dublin. Called smart fit or something. I pm'd yhe croppster but he is obviously off working hard as hasnt had chance to reply.

 

[Ermintrude]

Buy the green-star one it's about £165 and will manage 70keggawhos