Recommended UFH Spacing

BarneyMc

This might be a very general question but is there a "recommended" spacing for UFH pipes to be laid?

I've heard 150mm spacing is common but is there an argument for 100mm spacing?

I assume this reduces the required temperature of the water and therefore makes life easier for the heat pump?

More pipework will obviously cost more to install but you only get one go at that.

hexosan

I've had different suppliers recommend 100,150 & 200mm spacings. Your correct in assuming that the closer the spacing the lower the water temp required.

DeeJunFan

have a report from a renewable consultant and he specifies max 150mm for use with air source and to use 100mm in any high glazing areas (sun rooms etc)

Chats with a few UFH suppliers have confirmed this seems to be the standard with Air Source heat pump.

BarneyMc

DeeJunFan wrote: »

have a report from a renewable consultant and he specifies max 150mm for use with air source and to use 100mm in any high glazing areas (sun rooms etc)

Chats with a few UFH suppliers have confirmed this seems to be the standard with Air Source heat pump.

Interesting. So it looks like 100mm is a good bet then as a general rule of thumb.

DeeJunFan

BarneyMc wrote: »

Interesting. So it looks like 100mm is a good bet then as a general rule of thumb.

I have also spoken to a guy in Mullingar and he recommended looking at heat calcs for each room and designing the spacing on a per room basis. So two rooms of the same size with the same amount of glazing but one on the north side and one on the south side would need different heat loads.

Suppose it depends if you have that kind of detail.

But as you say if 100mm is good enough for sun room it should be more than enough for general living spaces.

BarneyMc

All my main spaces are on the southern elevation. Do the pipes have to be placed in 50mm jumps or can you have any spacing, e.g. 125mm?

Curious Geroge

Is there also different sizes for the underfloor pipes themselves ?

I heard a salesman tell me there is also different ways to lay the pipes, the way he does and the bad way. Is there some way this needs be done done ?

esox28

Curious Geroge wrote: »

Is there also different sizes for the underfloor pipes themselves ?

I heard a salesman tell me there is also different ways to lay the pipes, the way he does and the bad way. Is there some way this needs be done done ?

Don't know about different pipe sizes to the regular 16mm, but that's not to say there isent.

There are two main patterns to laying ufh that we use with variations to both depending on room shape, how many circuits supplying the room and if it has a peripheral zone in addition to the occupied zone.
The main method we use is call a double meander pattern, basicly your first flow runs into the area and loops at the top of the circuit leaving space for two more runs of the return loop as the circuit is being completed.

The other is called a reverse spiral only used this once, again as the name suggest it runs in a spiral form around the area again leaving a double pipe space for the return to loop back on its self.

In essence the format for laying ufh can take any shape once you follow the principle of....

Flow pipe
Return pipe
Return pipe
Flow pipe
Flow pipe
Return pipe
Etc
Etc

I'll root out some pics over the weekend.

DeeJunFan

So far i've seen 12,16,20,25 and 32mm pipe.

But 16 seems to be the standard.


Thanks

esox28 wrote: »

Don't know about different pipe sizes to the regular 16mm, but that's not to say there isent.

There are two main patterns to laying ufh that we use with variations to both depending on room shape, how many circuits supplying the room and if it has a peripheral zone in addition to the occupied zone.
The main method we use is call a double meander pattern, basicly your first flow runs into the area and loops at the top of the circuit leaving space for two more runs of the return loop as the circuit is being completed.

The other is called a reverse spiral only used this once, again as the name suggest it runs in a spiral form around the area again leaving a double pipe space for the return to loop back on its self.

In essence the format for laying ufh can take any shape once you follow the principle of....

Flow pipe
Return pipe
Return pipe
Flow pipe
Flow pipe
Return pipe
Etc
Etc

I'll root out some pics over the weekend.

DeeJunFan

DeeJunFan wrote: »

So far i've seen 12,16,20,25 and 32mm pipe.

But 16 seems to be the standard.


Thanks

I was having trouble with the written patterns but this diagram shows you the patterns and the water temps as it goes round the circuit.

BarneyMc

What's the minimum depth that can be used for a concrete screed for UFH, i.e. without cracking :-)

esox28

75mm for concrete screed with fiber mesh added to the mix.