Despite being accused of spouting *?!# and being called names not acceptable to the forums T&C’s and being of not a proper spark.. all the gear no idea or something.???
I will still, for what it’s worth, add my tuppence on this topic..
When looking at any problems on any existing domestic heating system it must be remembered not to assume it was wired and working correctly before, IMHO you always need to…
1/ know what the customer is trying to do..
2/ what the actual physical components you have got can do..
3/ and how the manufactures have designed them to work…
Most plumbers struggle if the wiring gets more complex than a boiler, a thermostat & pump.
So it’s often the case that an existing system may not be wired or working to its full potential or how the customer would like it to work...
UFH pipe temperature..
As Steve mentioned if the pipes are laid in solid floor the heat must be strictly controlled otherwise you can end up cracking the floor screed. So you cannot just run water from the boiler as you do to radiators.
Manifold..
A heating system may include multiple UFH manifolds and/or traditional radiators as well. Each group of UFH pipe loops are balanced within their own manifold, and it is the manifold pump that then circulates water at a regulated temperature around the loops. Obviously if the manifold loops are not balanced individual rooms would be too hot / cold when all zones on that manifold are active.
When setting up the UFH the flow rate around each loop is adjusted and balanced with the flow gauges on the top bar of the manifold..
e.g. the little red bar in the window of each zone gauge,
or
Obviously the physical lengths of individual zones affect the flow rate around zones, shorter pipe loops least resistance more water flow.!
The actuators to operate a particular zone sit on the bottom bar of the manifold..
So when a zone calls for heat, its actuator opens and water flows to that room..
Thermostats and operating times..
Traditional radiators put a block of intense heat on wall of a room that circulates up and around the room ..
typically heating the air above waste level.. (heat rises)
UFH puts a low level heat across a wide floor area that rises from floor upwards. Too much heat at upper torso & head level can leave a person feeling uncomfortable. Less heat at lower torso level is far more concussive to making a person feel comfortably and warm without being stifled.
UFH is designed to bring a comfortable uniform temperature to the lower torso level of a whole room, (not just one wall i.e. no cold patches at the parts furthest form a radiator), without wasting energy heating ceiling level where people do not sit or move around!
BUT it is also designed with a longer lag time to get the room up to temperature..
Also it generally has to heat through a floor covering, boards/concrete/tiles/carpets etc. not just open pipe or rad in free air.
Some customers think having the heating on for a long time is wasting energy & money…
But as it is a lower heat for a longer time NOT the same intense heat that traditional radiators uses
and the UFH should be put on well before the time that normal rads would be set to come on.
Clearly if only one pump was running the whole heating system and there is only one thermostat for the whole property, the heating will probably be on at the wrong times and if or when other rads or manifolds were on there is a greater probability that some floor zone are not getting the heat they need.
Your thinking about a separate clock per floor is on the right lines as again with the basic concept for energy saving... .
You only want to start warming up the rooms you are using..
In an ideal world you would want one of the individual programmable room thermostats for each UFH zone..
So they can all have their own times/ temps and/or manual override..
This is why you normally need separate thermostats and timer clocks to get the most out of UFH..
The JG control boxes are designed to combine multiple rooms stats/prog timers back to one group of manifold zones and control its associated pump and boiler heat call in one self contained box.
But that all depends on how much the customer wants it tidied up..
And what budget they are working with…
230v version
http://www.screwfix.com/p/jg-speedfit-jgprte-programmable-room-thermostat-240v/26761#product_additional_details_container
12v version..
http://www.screwfix.com/p/jg-speedfit-programmable-room-thermostat-12v/36700
The 12v version can be wired with CAT5, Alarm or Phone cables if you are going to do a major overhaul of the system..
I can never understand why a customer paying for UFH to be installed dosn't pay for sufficient room controls to get the most out of the system..?.
Like buying a car... but only ever sitting on the drive in it!
Disclaimer:
I am in no way stating this information is the only way any UFH system can be configured or that it is the only global way that every UFH system in the UK has to work..
Merely trying the expand a bit more on the concept of what the manifold pump does in a UFH system, as the question was raised earlier in the thread and it may be of some help to other reading this topic as well.
what does this pump actually do, its running even when all the actuators are open,
there is also another loop beside it with a temp gauge, so Im stumped as to what the pump is for,