UFH 8 zone Heatmiser System Under Floorboards

[AshleyH]

8 minutes ago, Nickfromwales said:

Shouldn’t matter at all as the manifold has its own pump and it’s the loops this pump services that were discussing the balancing of.  

Ok im not sure if hes piped this off the ufh system though, so adjusting the outlet valve increases decreases the flow to the loops. ill have to double check.

[Temp]

Before you change to auto balancing I would try an experiment to see how effective the floor loops are in the problem rooms when given max flow..

 

Allow house too cool down by turning down all stats overnight.

Open the balancers to give max flow to ONE of the problem rooms.

Next day turn up the stat in that problem room ONLY and monitor how long it takes for the floor and room to warm up.

 

If it heats up just fine then it might be a balancing issue. If it struggles to heat that room with full flow (other loops off) then there is another issue.

 

 

 

 

 

 

 

Edited October 2, 2020 by Temp

[AshleyH]

So the room has two loops in it. I can monitor that, the max flow rate I can get on the two loops to that room is around 4 l/min is that ok? That wound fully out. To get all the rooms to warm up the quickest wouldnt I just wind all the flow rates out to max 4 l/min? 

[ProDave]

1 hour ago, AshleyH said:

So the room has two loops in it. I can monitor that, the max flow rate I can get on the two loops to that room is around 4 l/min is that ok? That wound fully out. To get all the rooms to warm up the quickest wouldnt I just wind all the flow rates out to max 4 l/min? 

Well the design document you posted near the start of the thread only called for a flow rate of just over 2L/min, so if you are getting 4 that is good.  I don't think you can have too much.

 

So it must come down to the floor covering not letting enough heat through, or the room having a higher than expected heat loss.

[Nickfromwales]

Too much flow to a particular loop means another is possibly getting starved, as the former will be taking the lions share of the pump potential. 
Start the system from cold and balance only then, with all actuators open, and never any other way. 
This crude approach of balancing won’t solve the problem I’m afraid, as there are varying floor covering with differing characteristics of getting heat from the pipe to the room. 
Auto-balancing in real time will be the best you can hope for. Salus heads are the only way you can achieve this real time response. 

[ProDave]

5 minutes ago, Nickfromwales said:

Too much flow to a particular loop means another is possibly getting starved, as the former will be taking the lions share of the pump potential. 
Start the system from cold and balance only then, with all actuators open, and never any other way. 
This crude approach of balancing won’t solve the problem I’m afraid, as there are varying floor covering with differing characteristics of getting heat from the pipe to the room. 
Auto-balancing in real time will be the best you can hope for. Salus heads are the only way you can achieve this real time response. 

I hear what you are saying. But his problem is one room takes forever to heat up.  That room has plenty of flow, nearly twice the calculated required flow, and it is still taking ages to heat up.  The other rooms even with very much reduced flow seem to be heating up okay.

 

So yes in an ideal world you need to persist with balancing it so all rooms heat up at the same rate. BUT the main issue is why is this room taking so long to heat up, and I would say we have proved it is not a balancing issue so for the moment I see no point persisting with that line of attack.

 

I would next be using an IR thermometer to see the actual floor temperatures of the different rooms. My guess is the problem room will have a very much lower floor temperature due to the floor make up in that room not conducting heat very well.

[Temp]

12 hours ago, AshleyH said:

The installer did say going through 3 layers (floorboard, ply and the flooring) would reduce the heat but you'd think they'd be hotter than they are, the only other difference is the warm rooms hav tile flooring and the cooler room has laminate, this has underlay also?

 

Are you saying the room might have..floorboards, ply, underlay and laminate?

 

 

[AshleyH]

Yeah it has that’s why I’m thinking it takes longer to heat up? The kitchen etc has floorboards ply and tiles? 

[Onoff]

@AshleyH, out of interest is this a retrofit?

 

How much and what sort of insulation do you have under the floors?

[AshleyH]

This is the ground floor, we renovated and used the thermo insulation board which the pipes are run in, ontop of that we laid floorboards throughout and played over the top for the tiles and wooden flooring. 

[ProDave]

4 minutes ago, AshleyH said:

This is the ground floor, we renovated and used the thermo insulation board which the pipes are run in, ontop of that we laid floorboards throughout and played over the top for the tiles and wooden flooring. 

What thickness was the "thermo insulation board"?

 

Was that just laid on an existing concrete floor, or did you add more insulation underneath first?

 

Are all rooms the same? or is there something different about the problem room?

[Onoff]

31 minutes ago, AshleyH said:

This is the ground floor, we renovated and used the thermo insulation board which the pipes are run in, ontop of that we laid floorboards throughout and played over the top for the tiles and wooden flooring. 

 

If it's less that around 150mm of pir you are just leeching heat into the ground and then some. You'll like be gobsmacked as the %age losses you'll have there.

[AshleyH]

1 hour ago, ProDave said:

What thickness was the "thermo insulation board"?

 

Was that just laid on an existing concrete floor, or did you add more insulation underneath first?

 

Are all rooms the same? or is there something different about the problem room?

it was laid onto the concrete floor I believe but that was the Same throughout.  I’m not sure what Thickness it was it was supplied with the kit. 

 

36 minutes ago, Onoff said:

 

If it's less that around 150mm of pir you are just leeching heat into the ground and then some. You'll like be gobsmacked as the %age losses you'll have there.

im not sure tbh, I thought the idea of the boards was to deflect the heat up? 

 

I reckon it could have something to do with the room which isn’t the warmest doesn’t have anything above it, all the other rooms have rooms above them? Possibly why the heat isn’t holding well? It’s still warm just not as warm as the others? 
 

I have found though a slower flow rate heats the room up better? 

[ProDave]

Having "nothing above it" should make no difference if the loft is insulated.  Worth checking how much insulation is up there.

 

If you have found a slower flow rate warms up better, try reducing this room to the 2l/min in the design?

[Onoff]

35 minutes ago, AshleyH said:

it was laid onto the concrete floor I believe but that was the Same throughout.  I’m not sure what Thickness it was it was supplied with the kit. 

 

36 minutes ago, AshleyH said:

im not sure tbh, I thought the idea of the boards was to deflect the heat up? 

 

Anything "tin foil" like will to some extent reflect but the metal will heat up and radiate up as well as down. Hence the need for insulation underneath. 

 

Is there any insulation under the concrete floor?

 

Do you have a link to the kit, ref the thermo board thickness?

 

 

[Nickfromwales]

On 02/10/2020 at 13:27, AshleyH said:

will the Salus auto balancing actuators work with the heatmiser ufh8?

It appears not. I may make a call to see why and if it can be done with a little ‘engineering’. 

[AliG]

We had the kitchen in our old house retrofitted with UFH and a similar floor build up to this, except with tiles.

 

It really struggled to heat the room when it was cold, I had to turn the flow up to over 60C as you have done. But I don't think it would have been an issue in the kind of temperatures we have recently.

 

Can you post the charts from the Heatmiser. UFH can take a long time to heat up compared to radiators. It would be interesting to see two things, how fast he room is heating up, but also how quickly it cools down during the night if the heating is off or set back.

 

Most people on the site with better insulated houses might only see a 1C drop in temperature overnight with the heating off and low outside temperatures. Mine tends to drop 1-2C depending on the room and the outside temperature.

 

If I attach the kitchen in my house you see it cools down slowly, not as slow as some, it is a downstairs room with tiles and a screed over PIR floor. It heats up very quickly, you see a very sharp spike in the morning when the temperature increases.

 

If I attach bedroom 3 - It is upstairs, and above the garage, it also faces north and has a wooden floor, so it is by far the slowest room to heat up in the house.

 

I did spend a lot of time last winter trying to optimise the system and found that in the couple of rooms that lose a lot of temperature it was probably more efficient to only turn the heating down 1C during the night, otherwise the temperature fell so much during the night that the heating ran for hours in the morning to get them back up to temperature.

 

 

[AshleyH]

59 minutes ago, AliG said:

We had the kitchen in our old house retrofitted with UFH and a similar floor build up to this, except with tiles.

 

It really struggled to heat the room when it was cold, I had to turn the flow up to over 60C as you have done. But I don't think it would have been an issue in the kind of temperatures we have recently.

 

Can you post the charts from the Heatmiser. UFH can take a long time to heat up compared to radiators. It would be interesting to see two things, how fast he room is heating up, but also how quickly it cools down during the night if the heating is off or set back.

 

Most people on the site with better insulated houses might only see a 1C drop in temperature overnight with the heating off and low outside temperatures. Mine tends to drop 1-2C depending on the room and the outside temperature.

 

If I attach the kitchen in my house you see it cools down slowly, not as slow as some, it is a downstairs room with tiles and a screed over PIR floor. It heats up very quickly, you see a very sharp spike in the morning when the temperature increases.

 

If I attach bedroom 3 - It is upstairs, and above the garage, it also faces north and has a wooden floor, so it is by far the slowest room to heat up in the house.

 

I did spend a lot of time last winter trying to optimise the system and found that in the couple of rooms that lose a lot of temperature it was probably more efficient to only turn the heating down 1C during the night, otherwise the temperature fell so much during the night that the heating ran for hours in the morning to get them back up to temperature.

 

 

 

thanks for the info, I’ve attached the trends over the last week, baring in mind there are some sharp spikes where I have been playing around with it! 
 

Also I’ve attached the profile I’m using, we aren’t in the house during the days only in the evenings so I’ve set it to heat up as below? Would this be more energy efficient? 
 

 

[AliG]

So I see a couple of things here.

 

UFH is slower to heat a room that radiators. Depending on how fast it heats up it may need to be on over an our before the target temperature you are looking for.

 

If you tap on he three vertical lines in the right side of the screen as shown, it gives an option called optimum start. Using this, Heatmiser is supposed to calculate how long rooms take to heat up, so you set the temperature you want e.g. 22C at 6am and it calculates if it needs to switch on at 4.30 or 5 or 5.30 etc. I have mine set to a maximum of an hour as it heats pretty quickly.

 

It also gives you the option to change the temperature differential before the heating kicks in from 1C to 0.5C. I did this, as for example if the thermostat is set at 20C and the differential set at !c, the heating won't come on until 19C which is a little cold.

 

Do you want the rooms to be to temperature at 6am and 4pm, or did you set these times as before you end them to be at that temperate to give it time to heat up. If these are the times you want the temperature then it may simply be that you need to change the settings so it starts to heat up an our before you need it, it does not look to be heating up particularly slowly to me.

 

The other issue is setting the temperature back to 16C when you are not at home. I don't know what your local temperatures have been like, a couple of nights last week it got to 3-4C here, but it looks like you are sometimes losing temperature quite quickly at night, 3C over a couple of hours in the lounge. I suspect if it was really cold you would lose 4-5C. It will take a long time to heat back up from this kind of loss.

 

You probably need to look at the temperature during the night and when you are at work as being set at 20C so that if if gets really cold, the heating kicks in to stop the temperature falling even more, then it is less hard to get up to temperature at the required time.

 

Out of interest, have you felt it too cold or slow to heat up in the last week. The temperature has been normally between 20 and 22C which would seem reasonably comfortable. It looks like heating up last Sunday and Monday morning may have been an issue

 

 

 

[AshleyH]

Thanks for the info, what’s your differential set to 0.5? Yeah I set them to this so it would be warm by 7/8 and 5/6 when we were home? Should I keep the overnight temp up overnight and throughout the say even when we aren’t here? I just don’t want to be wasting energy? Do you drop your overnight temp at all? 

[AshleyH]

1 hour ago, AliG said:

So I see a couple of things here.

 

UFH is slower to heat a room that radiators. Depending on how fast it heats up it may need to be on over an our before the target temperature you are looking for.

 

If you tap on he three vertical lines in the right side of the screen as shown, it gives an option called optimum start. Using this, Heatmiser is supposed to calculate how long rooms take to heat up, so you set the temperature you want e.g. 22C at 6am and it calculates if it needs to switch on at 4.30 or 5 or 5.30 etc. I have mine set to a maximum of an hour as it heats pretty quickly.

 

It also gives you the option to change the temperature differential before the heating kicks in from 1C to 0.5C. I did this, as for example if the thermostat is set at 20C and the differential set at !c, the heating won't come on until 19C which is a little cold.

 

Do you want the rooms to be to temperature at 6am and 4pm, or did you set these times as before you end them to be at that temperate to give it time to heat up. If these are the times you want the temperature then it may simply be that you need to change the settings so it starts to heat up an our before you need it, it does not look to be heating up particularly slowly to me.

 

The other issue is setting the temperature back to 16C when you are not at home. I don't know what your local temperatures have been like, a couple of nights last week it got to 3-4C here, but it looks like you are sometimes losing temperature quite quickly at night, 3C over a couple of hours in the lounge. I suspect if it was really cold you would lose 4-5C. It will take a long time to heat back up from this kind of loss.

 

You probably need to look at the temperature during the night and when you are at work as being set at 20C so that if if gets really cold, the heating kicks in to stop the temperature falling even more, then it is less hard to get up to temperature at the required time.

 

Out of interest, have you felt it too cold or slow to heat up in the last week. The temperature has been normally between 20 and 22C which would seem reasonably comfortable. It looks like heating up last Sunday and Monday morning may have been an issue

 

 

 

 

 

[PeterW]

28 minutes ago, AshleyH said:

 

 

 

That setback is far too low - up it to 17c. 
 

I think the issue is that the room itself is losing heat - I’d check the insulation in the attic before doing much more. 

[AliG]

I used to have mine set back 2-3C, but I changed some rooms to 1-2C just so if they did cool down they would warm up faster.

 

If you want it to be 22C I would recommend setting it back to 20C during the night and when you are at work.

 

The 0.5C differential helps as at 1C it has to be1C away from the set temperature for the UFH to switch on, so say you want it to be 22C. The UFH switches off at 22C, it starts to cool down to 21C then it comes on. It could get to below 21C before it starts to warm up again. Thus with 1C you can find it getting colder than you would like before the heating kicks back in.

 

I am a bit confused though as looking at the charts, it doesn't look as if it is taking too long to heat up and the temperatures look broadly ok. The only thing is it looks like set at 22C it is dropping to 21C which you maybe find a bit cold in the lounge before the heating comes on. The 0.5C differential might help.

 

 

[AshleyH]

Thanks I will give it a go! 
 

Maybe it just doesn’t feel warm enough on the floor? I think adjusting the balancing has definitely helped and for some reason a slower flow rate seemed to work better?! 
 

My supply temp is quite high, I hope this won’t effect the system too much!? 
 

Isit worth getting the self adjusting actuators would this save energy ontop of these settings? 

[AliG]

I doubt would be worth the cost and effort. The biggest driver of the times and costs of heating is going to be the insulation of the room. You do have a faster heat loss than most people on the forum, but considering this is not a  new build, I don't think it is surprisingly fast.

 

It would be useful to know that there is enough insulation in the floor. Looking at the expansion foam around the edges, did they lay a concrete floor then put the insulation panels on top of it? Having looked on Google they look like they might be low profile panels that would not really provide enough insulation on their own and would allow a lot of heat to leak into the ground and slow down the system.

 

They may have made this choice to maximise head height or to not alter the floor levels.

 

I would be surprised if the floor was not warm at the temperatures you are running with makes me wonder about the amount of insulation in the floor.

 

 

 

 

Edited October 3, 2020 by AliG