Mixing valves for UFH

Page 1 of 2  
Been looking at blending valves for a floor heating circuit. Seems they are mostly sold as TMV3 for protecting basin outlets etc. Does anyone know if the TMV3 spec allows it to be set as high as 55deg?
TOby.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Have you thought about a roomstat to control a motorised valve ? The valve can be configured as two or three port and the stat' can be wired to allow both opening parameters.
http://www.heat-trace.ltd.uk/english/products/controls.htm#pt007
--
www.basecuritysystems.no-ip.com
Outgoing mail is certified Virus Free.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

wired to allow both opening parameters.

Going to have a digistat to switch the zone valve and fire the boiler for room temp control, still need water temp control as well. Yep. Thought about a 'binary' control with a motorised valve, shoot a load more hot in then stir that around for a while. I'm more keen on the proportional blending you'd get with a self-acting valve though. It's just I can get my hands on a TMV3 mixer for 32, whereas BES would do the 3 port UFH valve for 68+21+63(*).
Can I get hot enough water out of a TMV3? I've hunted high and low for the specs but drawn a blank.
Toby.
(*) http://www.bes.ltd.uk/products/n106.asp Parts #15756, 15762 & 15760/1
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
IMM wrote:

Electric valves are not required - a thermostatic mechaniocal by pass is entirely adequate.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

motorised
He wanted electric. Duhhh!!!
--
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com ).
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

required.
No I don't. I want a mechaniocal blender.
Toby.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

etc.
The
to
is
Sorry, BigWallop was on about electric.
--
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com ).
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Toby wrote:

See. He is a professional wanker.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

is
Who are you on about? I'm a man of leisure so can't be professional. Or do you mean the NG's favourte correspondent?
Toby.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

do
I think he means you.
--
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com ).
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Toby wrote:

www.polyplumb.co.uk - they do purpose made valves for U/F heating.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Found this: 22mm UFH mixing valve PB219058 92.80+v As it's only going to be a 15m circuit I'm seeing if I can economise with a 32 TMV3. Am I cutting too big a corner?
Toby.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

a
Price up the Reliance UHF blenders I gave the URL for. If the TMV3 is easily accessible, I suppose you could see how it works. If it is too slow to respond then change for a proper UFH blender.
--
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com ).
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

a
Where did you find TMV3s for 32?
--
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com ).
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Local independant (York) merchant has them. No boxes just polybagged. No idea what brand. 32 + v of course, 22mm is 38 + v Slightly unusual shape, not the standard T, they call them 'inline' TMV
H>>>>XXX The XX part is a vertical cylinder XXX>>>>Flow C>>>>XXX XXX \|/ Valve
Toby.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Toby wrote:

Oh heck - a tiddler?
So not even a separate UF pump?
You know i'd frankly say 'sod it' and lay the plastic pipe in some insulation if its being screeded, and forget about it (insulation) if its under a suspended wood floor.
The point of temp reduction is to protect the floor, not the pipe after all.
Any method that stops you cracking teh cioncrete by limiting heatflow will do.
e

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

with a

I've seen my systems (all eight of them now :-)) running up to a pipe temperature of 65 degrees on the flow side with no adverse effects to any parts of the structure or flooring, and I think you'll agree that 65 degrees is enough to keep the whole of the house loverly and cosy in the winter months.
I do have to admit that two of the systems have pipework buried in screed floors and these did show some signs of causing cracks around where the pipes are buried, but the cracks were filled with a very thin layer of a more wet mix and never reappeared. I put it down to me firing the system up to soon after laying the mix and it hadn't had time to cure properly.
None of the systems I've installed have anything other than normal central heating equipment installed in them, i.e. boiler, circulating pump, motorised valves and roomstats, and the people who I've installed them for, over many years now, have always complimented the way in which they work and the way their friends talk about how their systems always seem to have some kind of fault or another.
I've always just treated the pipework under the floors like any other kind of radiator, which it is, and never done anything fancy to systems other than put my installers mark on them. All in all, I think that to much is being engineered into these systems and that is what is causing a lot of problems and whoo haa about how hot it has to be and how far down the pipes must go. If anyone has felt the heat that radiates from the back of a standard radiator and goes against a stud partition wall, then it is exactly the same for the pipework under a floor.
I don't see the need to over engineer anything and I think it only causes more grief than it's worth.
I thank you, and good night. :-))
--
www.basecuritysystems.no-ip.com
Outgoing mail is certified Virus Free.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

There is a difference to over-engineering and not doing it correctly. You should learn about UFH and how to design and install it properly. UFH runs at low temperatures for a variety of reasons, preventing cracks in the screed being only one.
UFH is notorious for being either too hot or too cold when the weather changes, as it does in the highly changeable UK climate. This is because of the sluggishness of the system, the very slow response rate. Proper blending controlled by inside temperatures and feed forward control by outside weather compensation predicts the eventual temperature fall or rise reducing the too hot or cold discomfort.
I hope you are using proper barrier pipe under the floors, PEX. Are you? NEVER run UFH over 50C.
It is bad enough attempting to get know-it-all amateurs to comprehend matters, and you do this for a living?
--
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com ).
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

the
with
floors
each
programmer
Why Thank You. :-)) I wouldn't call them "CRUDE" systems as such, but I would call them "BASIC" heating systems. I don't see the point of engineering in, what is not absolutely necessary to make the system work at quite a high efficiency already. If you think about the pipework in place between the joists, working out to two lengths of pipes in each gap, then consider that they actually only radiate their heat into the space between the joists. This heat is then permeating evenly through the floor and into the living space above.
With this simple principle at work, and even with floor coverings such as carpet or laminates, the heat radiating through to the living space is kept at rather a comfortable level. With the addition of just one roomstat', positioned as close to the centre of the property as possible and at about light switch height, the temperature at the seating level is kept at a set rate.
What has been seen on these systems, is the fact that the running costs seem to be much less than friends tell of their systems. I think this is mainly due to the boiler only heating the water to the desired temperature with its own internal 'stat, and the fact that, when the system has been running for an hour or so, the area around the pipework has less heat loss due to it being already raised to a higher temperature. This then causes the boiler to fire up a lot less times in the initial start to compensate for the dramatic heat loses which occur, for a lot longer period, to a normal radiator in open air.
All I know is that I have been recommended to install two more of the same systems this year, and have arranged it so that the people move out to a holiday home for a few weeks this winter. I ask them to do this for only one reason, that is because it is a big upheaval to live in the same house with all the floor boards lifted to install the pipework. This is the only drawback with a system like this. But the holiday home is my own, and it is all in with the price of the system.
I allow two weeks for each installation, just to be on the safe side, to give plenty of time for testing and balancing of the systems. And this also allows for any settling times, finishing of decor' and things, between jobs that the install needs. This is all done before the people arrive back and means they don't have to walk in to real mess and dusty atmosphere.
--
www.basecuritysystems.no-ip.com
Outgoing mail is certified Virus Free.
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

No cude is the word.

The reason for this "over-engineering" as you perceive, is to create superior comfort levels. UFH is notorious for discomfort.

You refer to upper suspended floors. British homes are notorious for the slap building. The joist will invariably not be sealed where it enters the inner wall leaf. Then you loose heat to the cavity. the pipes should be touching the boards above for maximum heat transfer.
UFH pipes should not be fitted in a ground floor vented space unless the correct suspended floor underfloor plates are fitted with appropriate insulation, as you will be also be heating the street.

Not with the crude control you have. having UFH zoned means you can have electric blending valves that lower and raise the floors temps.

As I have said. Get is "zoned" correctly with adequate control on each zone.

I find that hard to believe.

That is roughly the case with all UFH

If you want a simple UFH system, zone it using a manifold, or make a manifold yourself. A manifold means all controls and adjusters are in one place. The zones cold be one front and back on the ground floors and the same on the 1st. Have one pump for the whole system and a zone valve on each zone operated via a room stat. Then have a condensing boiler with a DHW mode that ramps the boiler temp to full when DHW is called. Have a DHW priority system with quick recovery cylinder. Have the CH side of the condensing boiler set between 40-50C. No blender required and economic condensing boiler performance. If not a condensing boiler then have a blending valve and the boiler set to 80C, as you don't want condensing occurring in the boiler.
Ensure that insulation is under UFH heating pipes in suspended floors. In upstairs floors make sure the insulation is high density mineral wool as this will reduce sound a hell of a lot, so killing two birds with one stone. Having no insulation will mean you may be heating the ceiling beneath as above there is wood and laminate or carpet acting as a greater barrier to heat passing to the rooms above than the thin plaster board beneath the pipes.
"Always" have plastic barrier pipe under solid floors.
The above is for a "basic" UFH system. Ideally you would want the floor temp to modulate to demand (this usually means having a pump per zone) and as a real bonus anticipate the coming temp rise or fall by having outside weather compensation. A good zoned heating system can actually take solar gained heat from the south side of a house and distribute it to the north side.
Many people have been bitterly disappointed with UFH because the response rate is so slow meaning occasionally they will be too cold or too hot until the system catches up.
I seriously suggest to take on board much of what I have said.
--
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com ).
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.