I am trying to understand the pricing difference between UFH packages and buying the system components yourself for a heating engineer to install.

Even when I am looking at providing the materials myself for the engineer to install, packages from the reputable companies seem a lot more expensive than if I went to an online store. Naming no names, one such company quoted me £1600+VAT for a 39m2 package to run in screed; this is just the components - not the fitting or screed. It included the manifold. Yet online stores are offering 'packs' at less than half that.

So what's the likely difference? It could be the 'design' service but in my case I have a single 39m2 area that maybe requires two zones.

Could it be the pipe quality?

Has anyone had experience with buying UFH 'off the shelf' for a basic setup? If so can you recommend any brands, especially for the pipe that goes in the floor?

Have recently done a lot of research on UFH manufacturers and quizzing the installers around here one name kept on coming up, the german owned Robbens because of the quality of the components and excellent service. There was such a ground swell of positive opinions, I have just ordered a Robbens system.

Forgot to add I also chose them because they have been doing UFH sytems since 1992 and they have an insurance backed guarantee that has never been claimed on.

I had 3 companies quote for my UFH and all insisted on a design output of 50W per sq M at a flow temp. of 30 deg C. even though my heat loss calculations suggest a max. demand of 15W per sq. M. at an ambient of -10C. so in general they were specifying 3 times the amount of pipework that we required.

In the end after consultation with my house suppliers they suggested a layout of four loops of 16mm pipe each of equal length of 60m and treat the entire ground floor as one zone. They said that where they are installing the slab themselves (in my case they weren't) this is what they always do and they say it works well.

Approx. half my ground floor is one open plan area so I don't foresee major problems in this approach but will have to wait and see. As a very well insulated and airtight house I expect that it should all sit at roughly the same temp.

The total cost saving for supply and fit with this layout was about £5,000 compared to what the cheapest of the other designs were and about £8,000 compared to the dearest.

The pipe and fittings that were used are big brand name stuff but I can't remember which one off the top of my head.

Crusoe - is that £1200 installed or just the parts (excluding edge insulation & screed - which we already have)?

So are we saying that the difference in cost between the specialist packages and the online 'sheds' (i.e. ultracheapufh.com) is the quality and design service? Some of the sheds seem ok ...

If you've only got a couple of zones, buy your own pipe, add a couple of 2 port honeywell valves, and a few other bits and pieces for control. I never buy manifolds, and certainly not kits. Pipe is about £1/metre, and the other bits are not expensive. It may be more than a DIY amature could design, but not complicated, and the cost would be around £200 per zone. Worth considering?

I paid nu-heat £3000 + VAT for a 14 zone system, bit of a battle to zone each room seperately as I had been quoted. The manuals they provide are very good though.

Crusoe , polythene on top of insulation is spec. by manifacture of PUR board to protect it from degrading as a result of contact with screed.

Hi James

This will be the subject of the new thread. Cheers.

Posted By: aleca much better effect is achieved by using modulating electric valves

On this topic, are there any you recommend?

I'd thought of using 24v thermo-electric (i.e. wax capsule + heating element) ones, but I suspect that controlling them accurately from the software I'm going to write will be a project in itself - they have inertia, and I suspect they're also susceptible to changes in both ambient air temperature, and the water that's flowing near them too...

Motor on / motor off ("mo-mo") valves would be much easier, but I didn't find any UFH ones (only radiators, and it didn't look practical to fit them to a UFH manifold).

alec - I respect your opinion but would beg to differ on the manual mixing valves. I have had better results and a more controllable system with MMV and independently-adjustable balancing valves in mid-size zones of 2-3 loops rather than 1-loop, 1-zone actuators. The theory's great for economy, the practice hasn't proved so IME. And several times more customer complaints with the electric actuators. Any time a customer feels they have no control, they (often) don't - and it's more than my life's worth.

Caveat - many of the modern, DIY-type UFH setups don't supply balancing valves.

Mmm - your third paragraph appears to agree with my second sentence. Same track roughly.

So you get customer complaints do you? Cowboy!!

Eh - and I thought the customer was always right.... You are spot-on there IMHO.

Zoning is a different issue. Which needs a different solution for every building. When we fitted the Mk 1 version of Honeywell's CM programmable stat range back in the late '80s, they produced research, aided and abetted by the government's own, now-famous, DOE research (1 deg C drop in temp saves 10% of your fuel bill) which said that their machines, avoiding the hysteresis caused by the on-off cycles you mention, could save upwards of 15% if used sensibly. My experience with customers ever since makes me agree.

The on-off-or-not argument is polemic, as you can still save by going lower-higher (temperature stepping) without switching off per se. In other words, the temperature rather than the time has the final say. And you don;t always have to bring the temperature 'back up' again - the Jet take-off analogy, as your body can get used to lower temperatures, assisted by parts of a dead sheep wrapped around you...

Zoning allows you the luxury of experimentation, is good where you have different temp requirements in different parts of the house and/or at different times of day, allowing small, regular temperature changes. It is therefore flexible and good for the soul as well as the pocket. I could go on for days and have frequently been known to....

So yes, I guess you could say I love my zoning.

http://en.wikipedia.org/wiki/Placebo_button#Office_thermostats

Guys,

The other question which I never really understood 10 years ago when we put our first UFH in was if you should use pipe with a oxygen barrier or not? It was a lot more expensive at the time so we just used standard plastic PEX pipe. Is that still an option or are all pipes now with O2 barriers?

That's the theory Phil, though I suspect that, among the hoi-polloi of the plumbing world, many non-barrier pipes have been used for UFH and central heating, before barrier pipe came along! Exactly how much lifespan a barrier pipe adds if the system is well-inhibited anyway I have no idea. Nor, I suspect, do others. Unless somebody can point me to a study?