UFH design

[WWilts]

Looked at CAD designs from suppliers, tweaked inputs, arrived at this.

 

Any problems obvious?

 

Circuit temperatures

Circuit layouts

Circuits & heat losses

Peak capacity

Room surface temperature

Zones

Edited September 27, 2021 by WWilts

[ProDave]

I take it the pipe spacing is not to scale?

 

Don't run ANY pipes through the Larder, take them around it.

 

Are you seriously suggesting not putting pipes under the sofa's in the living room?

[WWilts]

Pipe spacing drawn at (or very near) scale. Obvious problems?

Good idea to take pipes around larder rather than through it.

 

Currently no pipes under major furniture in living room. Bad idea?

[dpmiller]

it's only a sofa, people do move them...

[Jenki]

On 27/09/2021 at 10:55, WWilts said:

Pipe spacing drawn at (or very near) scale. Obvious problems?

The Spacing to me seems to vary massively,  kitchen extremely close,  living hardly any?

On 27/09/2021 at 10:55, WWilts said:

Currently no pipes under major furniture in living room. Bad idea?

IMO Very bad.

 

Also, I struggle with any in slab / in screed systems not incorporating the spaces under kitchen units.  This is a thermal mass so will heat up anyway, or in my view draw the heat away for the areas you are heating.  I personally use the whole area and pipe space accordingly.  -- BUT I must be wrong as every designer do it.... 

Can anybody help me to understand why? 

Electric over floor heating I'm okay with  

[epsilonGreedy]

Why design for a higher target temp in the kitchen than the living room? I would want the reverse.

 

The layout pipe patterns are far too fussy, any UFH installer will laugh at your diagrams and run the pipes in simple repeating patterns.

[LA3222]

2 hours ago, Jenki said:

Also, I struggle with any in slab / in screed systems not incorporating the spaces under kitchen units.

This^^^

 

I too fail to understand this. If you are putting UFH pipes into a massive slab the only place I would not put pipes is next to wastes or where you plan on fixing into the floor.

 

Any parts of the slab which are unheated will just suck heat towards them so the whole slab will eventually reach an equilibrium of sorts - maybaswell put pipes in to speed this up.

[WWilts]

3 hours ago, LA3222 said:

Any parts of the slab which are unheated will just suck heat towards them so the whole slab will eventually reach an equilibrium of sorts

I don't pretend to be an expert, but the professionals advised no UFH under kitchen island.
Hopefully heat will rise and heat the whole space including those parts of the room where UFH pipes are omitted

[WWilts]

5 hours ago, epsilonGreedy said:

higher target temp in the kitchen than the living room?

Kitchen/family room north facing incl big window. Same target temperature 21 degr C as other rooms. Higher surface temperature in kitchen probably needed to heat the spaces where pipes are omitted. Also to allow heat to waft up the stairs.
Living room south facing, relatively less openings in walls.
Individual room thermostats should help regulate the actual temp.

But yes, design needs a careful second look before being finalised. Installation still some way off. Suspect installers will be glad to be allowed wider spacing (less work) if that is found satisfactory by a client. But the client does indeed need to look again and be absolutely sure.

Edited October 2, 2021 by WWilts

[ProDave]

You balance all the rooms by adjusting the water flow rate through each of the pipe loops with the aim being to get all the rooms to heat up at roughly the same rate.

 

I omitted pipes under the kitchen units and in particular none under the fridge, but i did not compensate with changing the spacing, normal balancing was all that was needed.

[epsilonGreedy]

3 hours ago, LA3222 said:

This^^^

 

I too fail to understand this. If you are putting UFH pipes into a massive slab the only place I would not put pipes is next to wastes or where you plan on fixing into the floor.

 

 

Until reading this thread I was planning to omit ufh pipes below fixed kitchen units. I still think the idea has merit where the counter top is along the boundary of the room. Given the 600mm depth of a counter and the need for pipes at say 200mm for an even floor temp, this suggest a useful temperature gradient under fixed kitchen units when no pipes are present.

 

Skipping ufh pipes under an island is another matter.

[epsilonGreedy]

35 minutes ago, WWilts said:

Suspect installers will be glad to be allowed wider spacing (less work) if that is found satisfactory by a client. But the client does indeed need to look again and be absolutely sure.

 

 

I have watched the ufh pipe installation at a neighbour's house and concluded intricate layout plans are a bit theoretical when it comes to fixing down the pipe from the reel. The plastic pipe seems to have its own idea where it should go.

Edited October 2, 2021 by epsilonGreedy

[WWilts]

15 minutes ago, ProDave said:

get all the rooms to heat up at roughly the same rate

Understood.
Anticipating kitchen/family room will have most occupancy. Don't mind having cold rooms, using thermostats, if nobody is in there. Not very nice for guests, I know, unless they go into the kitchen.

[WWilts]

Scrapped all heating from first floor (except bathrooms). Took on board comments. Now UFH downstairs design looks more normal. Landing at foot of stairs is its own zone in case need heat to go upstairs.

 

7 zones, 9 circuits. Temperature of water 41 degr C. Design to take 0 degr C externally, maintain 20 degr C internally.

Any obvious problems?

Edited October 5, 2021 by WWilts

[joth]

On 02/10/2021 at 09:25, Jenki said:

 

Also, I struggle with any in slab / in screed systems not incorporating the spaces under kitchen units.  This is a thermal mass so will heat up anyway, or in my view draw the heat away for the areas you are heating.  I personally use the whole area and pipe space accordingly.  -- BUT I must be wrong as every designer do it.... 

Can anybody help me to understand why? 

our heating isn't on yet bit In a couple months I'll get some thermal imaging photos for you. But in short, the non-heated areas of screed sit at a reasonably steady 20°C same as the room temperature, but the heated areas go to flow temp, 25°C for us but obviously higher for people that run higher flow temperatures. And varies in temperature more.

So personally I don't want that under anywhere I might stood fresh food or my wine stash. The cat litter tray also sits on a non-heated section as no one wants that warmer than strictly necessary

 

I do agree if you want to maximize the thermal store potential of the screed, maximizing the UFH loop area does make sense. 

Edited October 6, 2021 by joth

[jack]

9 hours ago, WWilts said:

Landing at foot of stairs is its own zone in case need heat to go upstairs.

 

I'd be careful assuming that you'll get much, if any, heat moving upstairs as a result of maybe a square metre of warmer floor at the foot of the stairs. It depends on the floor temperature of course, but UFH isn't like radiators. In particular, the temperature difference with UFH isn't enough to generate convection currents.