LLH required?

[virgilns]

So I was thinking of zoning pretty much each room to give me a fully tailorable heating system future proofed and hopefully as economical as possible. Boiler is on middle floor, ground floor is 4 rooms, middle floor 3 beds two baths and top floor 2 beds.

The idea was:
Flow and return pipes going upstairs with 2 2 port valves for heating in the two room and two stats
Flow and return pipes going down stairs and 4 zone valves and 4 stats, one pair for each room off a small 28mm 'manifold'
Flow and return running down the landing for the middle floor and 2 port zone valves for the 15mm pipes flow and return to each rad.

Had my boiler chap come round tonight and he's suggested a LLH and the flow and returns coming from this. The idea is that it provides a quicker heat up time and less issues with balancing. He's worked on commercial systems before and seemed very sure that was the best idea and that 3 long flow and returns with zones off them would be a nightmare.

My worry is that:

1) it increases the pipework considerably
2) he's suggested one larger pump for the primary also being able to provide adequate flow for the secondaries to each rad....each LLH system I've just been googling has a separate pump for each circuit from the LLH
3) the costs are running away with me whe the original idea was to save cash in operation through more efficient use...if I;m spending 1000's on a small commercial install (all at my own instigation) the Return On Investment will be much more drawn out

I know I could use TRVs but i don't get easy on/off and separate timed control of the separate living areas...

Or I could just have 3 zones plus heating (If I went this route, would 3 22mm feed and returns, one to each floor be adequate for a 2500sq ft house?)

Cheers, and sorry about the rambling...4hrs of googling and reading forums has fried my brain a little!

 

[muggles]

Pipe it up using the standard method and use either the Honeywell or Terrier digital programmable TRVs for control, you'll achieve the same effect for much less money

EDIT: Google Honeywell evohome and Terrier iTemp

 

[Dan Robinson]

Just use an underfloor heating manifold with the correct number of ports and run 10mm to each rad and control the system like you would with underfloor.

 

[virgilns]

Just use an underfloor heating manifold with the correct number of ports and run 10mm to each rad and control the system like you would with underfloor.

10mm? and all the manifolds I;ve seen are for plastic push fit...I'd rather go copper all the way if possible...are there copper manifilds out there?

 

[Dan Robinson]

Not specifically.

But why make life hard on yourself?

10mm barrier to each rad will mean zero joints under the floor and will provide ample heat.

 

[Agile]

This is a typical larger home and you have ideas of controlling each room seperately all because you dont want to use the TRVs ( which you need to fit anyway! ).

The cheapest solution is to use the programmable TRVs! One pump and no header!

The most expensive is up to you.

The manifolds with electric valves are a simple way to combine all the control in one spot. Not convinced that it will be much cheaper though. The you have the spaghetti effect of 18 ten mill tubes coming off it. But you will not need the low loss header and only one pump!

A friend has a five bed house and 26 heating zones! But he is a bit mad and has too much money! He used to be as HVAC lecturer!

Tony

 

[JonCa]

Thought you did not need TRV's in a room if you had a controlling thermostat in that room or have the targets moved again? Proposition seems to be Tstat + zone valve per room.

Re Programable TRV's quite a difference between Evohome and iTemp.
Evohome is a full control system where each HR80 TRV triggers heat demand signal according to time/temp requirements from Evohome panel.
iTemp is a simple programable TRV (although seemingly better functionality than most new gen units) it has no means to switch the heating on and off. In fact iTemp state that it is not a zoning device unlike the Evohome.
But there is a major difference in price.

 

[virgilns]

This is a typical larger home and you have ideas of controlling each room seperately all because you dont want to use the TRVs ( which you need to fit anyway! ).

The cheapest solution is to use the programmable TRVs! One pump and no header!

The most expensive is up to you.

The manifolds with electric valves are a simple way to combine all the control in one spot. Not convinced that it will be much cheaper though. The you have the spaghetti effect of 18 ten mill tubes coming off it. But you will not need the low loss header and only one pump!

A friend has a five bed house and 26 heating zones! But he is a bit mad and has too much money! He used to be as HVAC lecturer!

Tony

Out of interest, why woudl I need to fit TRVs if each room (Zone) is on a 2 port and each has a thermostat?

Just looked at the Honeywell eco (is thtis what's meant by programable trvs) and it's a good halfway house between full zoning and trvs, it seems...and on 'normal' pipework...anyone fitted one?

The only downside is honeywell say it can't control an unvented, so that'd have to be a separate controller

 

[muggles]

Removed due to talking out of my arris!

 

[JonCa]

Just looked at the Honeywell eco (is thtis what's meant by programable trvs) and it's a good halfway house between full zoning and trvs, it seems...and on 'normal' pipework...anyone fitted one?

The only downside is honeywell say it can't control an unvented, so that'd have to be a separate controller

Believe that its rather better than a halfway house, each TRV can be in a group which may be just one room or a group of rooms. so you can configure a nice solution. I think you can hang a XYZ plan off of a control port on the Homeplan so would have thought unvented was not an issue but.... If not there are other Honeywell Homeplan equivalents.

 

[Agile]

Out of interest, why woudl I need to fit TRVs if each room (Zone) is on a 2 port and each has a thermostat?

Practically of course you dont as the individual zone would take of controlling the room temperature.

But because they are for the normal situation the Building Regs say that TRVs should be fitted.

 

[virgilns]

Out of interest, why woudl I need to fit TRVs if each room (Zone) is on a 2 port and each has a thermostat?

Practically of course you dont as the individual zone would take of controlling the room temperature.

But because they are for the normal situation the Building Regs say that TRVs should be fitted.

The approved doc says that or the actual regs? Can;t see how it would not pass with a fully zoned (even if it IS massive overkill) system...

 

[virgilns]

Just looked at the Honeywell eco (is thtis what's meant by programable trvs) and it's a good halfway house between full zoning and trvs, it seems...and on 'normal' pipework...anyone fitted one?

The only downside is honeywell say it can't control an unvented, so that'd have to be a separate controller

Believe that its rather better than a halfway house, each TRV can be in a group which may be just one room or a group of rooms. so you can configure a nice solution. I think you can hang a XYZ plan off of a control port on the Homeplan so would have thought unvented was not an issue but.... If not there are other Honeywell Homeplan equivalents.

MY only issue is it's:

A) wireless (i much preffer wires as they dont; run out of battery and the signal is as good as the copper...)
B) still taking the temop reading right next to the radiator which can't be the most efficient place to measure the room temp...which is my issue with normal TRVs

 

[Agile]

Its obviously better to have a stat remote from a rad.

But practically if the room is reasonably insulated and free from draughts a TRV can be adjusted to very accurately control the room temp.

Just think of it as being offset to compensate for the effect of the radiator beside it.

There are no TRV police and I have never heard of anyone getting any trouble from having no TRVs or even worse not even any room stat. I would say that 35% or rented flats in London have no working roomstat!

Tony

 

[Onetap]

10mm? and all the manifolds I;ve seen are for plastic push fit...I'd rather go copper all the way if possible...are there copper manifilds out there?

Is it a new house or complete strip out? Would UFH be practical, if you're going to the expense of a multi-zone system? You'd also gain the floor insulation. Copper's nice, but it's getting eye-wateringly expensive.