Self Build UFH With Radiators

[paulie1970]

I am not in the profession so please bear with me...

For a larger energy-efficient self-build house the design has allowed for UFH on the ground floor and radiators upstairs (5 bed) coupled to a Greenstar CDi. The downstairs UFH is zoned, but with simple (polypipe) thermostats, rather than individually programmed units with time profile setbacks. The upstairs radiators have manual control valves only.

The plumber is proposing to add a Drayton LP241 programme timer which will give 3 x heat events for all heating circuits and hot water.

To me this seems far too simplistic a solution and will lead to unnecessary heat demand in the early mornings, where heat in the sitting rooms (including a sun room) is not needed, but because of controller limitations bedroom heat requirements invoke all UFH and vice versa when sitting room UFH heat also warms up bedroom radiators.

Despite the overall efficiency of the house (EPC grade A) I am not convinced of the efficiency of the boiler heat distribution setup, yet most of it (other than the timer) is already in place. Has the plumber taken a sensible approach, are my concerns justified and can anything be easily retrofitted?

 

[jonnyswamp]

What did you ask your plumber to quote for originally?

 

[AWheating]

is the underfloor on a manifold? was it designed by the manufacturer? if so what controls was on the design?

 

[Chalked]

You need programmable thermostats on each underfloor zone. A programmable room thermostat for your radiators, a programmer for hot water times ( do not use a combi on a 5 bedroom house!)
Thermostatic rad valves.
You will then have an efficient, easy to control heating system, with plenty of hot water.

Again. DO NOT USE A COMBI!!

 

[jonnyswamp]

I read it as he has basic stats on every u/floor zone, basic stat for upstairs (every rad has a manual TRV) and a cyl stat for hot water, with a 3 channel programmer
This is what I would include in a quote for a new build, if the customer then decides to go all singing and dancing, it's extra
Don't know your circumstances, but have a chat with your plumber first

 

[paulie1970]

System exactly as per Jonnyswamp - not a combi boiler. Sounds like it is not too wide of the mark then? Perhaps better to keep it constant temp downstairs rather than waste energy cooling and raising the slab. I guess the UFH thermostats could be replaced with programmable ones in the event that extra control needed at later stage.
Thanks for reading & responding.

 

[Worcester]

Are you still at design stage?

New build there are far far better solutions, you need a good heating engineer not a plumber .

If we were designing it, we'd do:

Downstairs: Room by room programmable stats Heatmiser Neo ideally (else Heatmiser PRT if tight on budget)
Upstairs use the same stats to create mutliple zones (seperate for towel rails and rads) and add TRV's to all the rads except where the one stat is, alternatively for upstairs look at Honeywell evohome - room by room control on TRV's

Also being new build your energy efficiency will be such that a well designed and installed Air source heat pump will be cheaper to run and you'll get government support to install it.

Sack your plumber, get a heating engineer.

 

[Worcester]

yet most of it (other than the timer) is already in place. Has the plumber taken a sensible approach, are my concerns justified and can anything be easily retrofitted?

Sorry just seen that bit!

Yes your concerns are fully justified

Put programmable room stats wherever you can, if necessary wireless ones (Heatmiser / Honeywell) and control each ufh room individually, plus as I said for upstairs. It should all be able to be retrofitted.

He might also need to update the ufh controller, though that's easy enough to do

Sound like he was either cutting corners or didn't know what he was doing and took advice from his merchant

He also needs to give you an ERP certificate for the installation (boiler and heating system) ours typically come out at at least A++.

 

[lame plumber]

being as its self build, i expect that money is the main constraint on this one worcs, you lot cost too much

 

[Worcester]

being as its self build, i expect that money is the main constraint on this one worcs, you lot cost too much

Thanks lame Actually that is typical entry level spec for our self build customers - and they represent about 50% of our business volume, we find that self builders usually go for a higher specification than developers as it's their home and they've got one chance to get it right, so are prepared to invest upfront to reduce their long term running costs - cheaper to pay once than every year for the next 20

In practice by far the majority of our customers go for full remote control - as a minumum Heatmiser Neo / Honeywell Evohome throughout with room by room control across the whole house

 

[Chalked]

Thanks lame Actually that is typical entry level spec for our self build customers - and they represent about 50% of our business volume, we find that self builders usually go for a higher specification than developers as it's their home and they've got one chance to get it right, so are prepared to invest upfront to reduce their long term running costs - cheaper to pay once than every year for the next 20



In practice by far the majority of our customers go for full remote control - as a minumum Heatmiser Neo / Honeywell Evohome throughout with room by room control across the whole house

Heatmiser neo are cracking stats. I prefer hard wired myself, then no problems with batteries. Don't forget to tell the sparky to fit deep back boxes and 3 core!