Upstairs heating options for passivehaus - electric or wet systems; looking for advice

[JohnMo]

29 minutes ago, saveasteading said:

My excuse is that a 6 x 2 is not a measurement

They are not even that size. Well confused me when I first started buying timber.

[TerryE]

6 hours ago, saveasteading said:

Maybe this is in jest. But we should use British English on this site to maintain our good  example and credibility.

 

My excuse is that the idiom is a US one. We would probably say "Do the sums". 🤣

 

I had a shower in my 20°C unheated en-suite earlier. I survived. 

[-rick-]

Just now, TerryE said:

I had a shower in my 20°C unheated en-suite earlier. I survived. 

 

Isn't the point of self building/renovation to create an environment that is a pleasure to live in, not just a place to survive? 😉

[Nickfromwales]

4 hours ago, -rick- said:

 

Isn't the point of self building/renovation to create an environment that is a pleasure to live in, not just a place to survive? 😉

Yes, it is!! Some folk need to take a day off lol.

 

However........

 

20 degrees C in a passive house (ish) setting is absolutely NOTHING like 20 in my stone survival pod. At 18 degrees and with MVHR / UFH these dwellings just perform so much comfortably then a 'naturally aspirated, box of upset', such as mine. I just pay the gas bill and don't read it for too long.

 

@-rick-, are you in a super-duper, energy efficient and low temp dwelling with MVHR currently?

[-rick-]

Just now, Nickfromwales said:

20 degrees C in a passive house (ish) setting is absolutely NOTHING like 20 in my stone survival pod.

 

I know, hence the wink.

 

Just now, Nickfromwales said:

@-rick-, are you in a super-duper, energy efficient and low temp dwelling with MVHR currently?

 

No. The bathrooms are fairly stable (internal rooms so keep the heat) but I'd guess it's about 19 in there when I go for a shower at this time of year. It's ok but would prefer warmer.

 

I've recently started running my heating 24hrs with a setpoint of most of the flat at 18 and 22.5 where I use the computer. 18 is cool but ok if I'm moving around. Pretty sure I'd be ok with lower than 22.5 when I'm sedentary if it wasn't for the massive heat suck from my crappy aluminium windows. Before when doing on/off style heating I was still cold with the thermometer at 23.5 because the concrete floor was sucking the heat out of my feet.

[Great_scot_selfbuild]

Thank you for all the very helpful input - the cooling comments haven't been lost on me at all. We do like a cool bedroom and prior to having the detailed SAP calcs and part O modelling done, we were looking into AC / ASHP cooling modes and how effective they are/aren't (i.e. as others have said - don't expect anything immediate or particularly noticeable over a short period of time). We nearly got taken in by some of the MVHR / combo-cooling sales pitches but were saved a lot of £££ by some advice from here.

 

I'm happy to say our plans have reverted back to our original basis (simpler than my OP):

1. Wet UFH downstairs, single zone (open circuit, single zone valve control (which we may / could connect into our KNX system - we're starting with a simple KNX implementation but with the wiring and fabric of the design so that we could expand it later when our bank balance has recovered...).
2. Electric UFH pads in the bathrooms (tiled - this is more for comfort & experience rather than as a 'heat the room' source). These could be connected into the KNX system too.
3. Electric towel rails in bathrooms.

Question re: UFH pads under tiles:

We're looking at these two options; they would be installed on top of 22mm Caberdek floor with tiles on top. Has anyone any advice on using the self-levelling compound (10mm) on top of this sort of wiring? How do you get it level and how do you prime / waterproof the floor and timber edges? (10mm is so shallow - the 75mm wet screed is easy to visualise).

 

UFH pre-wired pads: https://www.thefloorheatingwarehouse.co.uk/product/150watts-m²-thermrite-mat-full-self-adhesive-backing-for-easy-install/

https://www.thefloorheatingwarehouse.co.uk/wp-content/uploads/2021/11/ThermRite_Mat_Instructions_150_CR.pdf

 

UFH loose wire - pinned down to a set layout/principles, but allows us to fit neatly around objects like bath, toilet, vanity unit etc.: https://www.thefloorheatingwarehouse.co.uk/product/thermrite-dual-core-heating-cable/

Installation manual: https://www.thefloorheatingwarehouse.co.uk/wp-content/uploads/2022/11/ThermRite-In-Screed-Cable-Installation-Manual.pdf

 

I'll dig out some images of the house layout if you're interested.

[saveasteading]

8 minutes ago, Great_scot_selfbuild said:

the self-levelling compound (10mm) on top of this sort of wiring? 

I don't see what the problem is. We have this and a heated towel rail in an unsuite. The heating mat simply glues to the deck ( a marmox board in our case)and is negligibly thin. Then tiles went on with normal tile adhesive. 

[Iceverge]

Passive class house here.

 

I made every decision based on cost as I'm so tight I lick the drips out of the milk carton.

 

No central heating to begin with. House too cold, 17-18deg.  Nicked this from my parents shed and plugged it in (anywhere downstairs was fine) .

 

 

 

It broke after 2 years so I went to the dump and pulled another one from the scrap electrical pile. (True story)

 

Then electric prices doubled so I put an A2A unit in the downstairs hallway. It squirts enough calories into the house to keep it all toasty.  Haven't tried cooling yet as that would unnecessarily disturb the spiders in my wallet. 

 

Bathroom was a bit chilly on my man boobs so I put in one of these in one bathroom. It cost €30. The kids had to make do without sawdust on their gruel for a month. 

 

 

It hit the spot but the tips of my ears were hotter than the tips of my toes and that pisses me off.

 

So then I bought one of these for the downstairs communal bathhouse. €60, Christmas has been cancelled until 2030.

 

 

It fluffs up my curlys excellently and delivers a beautiful Saharan breeze to my eyeballs. Better than the 2 bar fire above. 

 

Best of all I made sure to hang it on a stud wall so it makes a racket and you never forget to turn it off. 

 

Total capital ofheating...........

 

~€1600.......

 

Annual heating usage 2025 for 186m². 

 

 

 

That is excluding the twiddly bits (~30kWh) for warming my titty bits in the shower. 

 

 

Like @TerryE says do da numbers y'all..🇺🇸

 

 

 

[Nickfromwales]

11 hours ago, Iceverge said:

Passive class house here.

 

I made every decision based on cost as I'm so tight I lick the drips out of the milk carton.

 

No central heating to begin with. House too cold, 17-18deg.  Nicked this from my parents shed and plugged it in (anywhere downstairs was fine) .

 

 

 

It broke after 2 years so I went to the dump and pulled another one from the scrap electrical pile. (True story)

 

Then electric prices doubled so I put an A2A unit in the downstairs hallway. It squirts enough calories into the house to keep it all toasty.  Haven't tried cooling yet as that would unnecessarily disturb the spiders in my wallet. 

 

Bathroom was a bit chilly on my man boobs so I put in one of these in one bathroom. It cost €30. The kids had to make do without sawdust on their gruel for a month. 

 

 

It hit the spot but the tips of my ears were hotter than the tips of my toes and that pisses me off.

 

So then I bought one of these for the downstairs communal bathhouse. €60, Christmas has been cancelled until 2030.

 

 

It fluffs up my curlys excellently and delivers a beautiful Saharan breeze to my eyeballs. Better than the 2 bar fire above. 

 

Best of all I made sure to hang it on a stud wall so it makes a racket and you never forget to turn it off. 

 

Total capital ofheating...........

 

~€1600.......

 

Annual heating usage 2025 for 186m². 

 

 

 

That is excluding the twiddly bits (~30kWh) for warming my titty bits in the shower. 

 

 

Like @TerryE says do da numbers y'all..🇺🇸

 

 

 

Does your local pub have an engraved 1/4 pint glass for when you go out for a beer?

[Nickfromwales]

11 hours ago, Great_scot_selfbuild said:

Thank you for all the very helpful input - the cooling comments haven't been lost on me at all. We do like a cool bedroom and prior to having the detailed SAP calcs and part O modelling done, we were looking into AC / ASHP cooling modes and how effective they are/aren't (i.e. as others have said - don't expect anything immediate or particularly noticeable over a short period of time). We nearly got taken in by some of the MVHR / combo-cooling sales pitches but were saved a lot of £££ by some advice from here.

 

I'm happy to say our plans have reverted back to our original basis (simpler than my OP):

1. Wet UFH downstairs, single zone (open circuit, single zone valve control (which we may / could connect into our KNX system - we're starting with a simple KNX implementation but with the wiring and fabric of the design so that we could expand it later when our bank balance has recovered...).
2. Electric UFH pads in the bathrooms (tiled - this is more for comfort & experience rather than as a 'heat the room' source). These could be connected into the KNX system too.
3. Electric towel rails in bathrooms.

Question re: UFH pads under tiles:

We're looking at these two options; they would be installed on top of 22mm Caberdek floor with tiles on top. Has anyone any advice on using the self-levelling compound (10mm) on top of this sort of wiring? How do you get it level and how do you prime / waterproof the floor and timber edges? (10mm is so shallow - the 75mm wet screed is easy to visualise).

 

UFH pre-wired pads: https://www.thefloorheatingwarehouse.co.uk/product/150watts-m²-thermrite-mat-full-self-adhesive-backing-for-easy-install/

https://www.thefloorheatingwarehouse.co.uk/wp-content/uploads/2021/11/ThermRite_Mat_Instructions_150_CR.pdf

 

UFH loose wire - pinned down to a set layout/principles, but allows us to fit neatly around objects like bath, toilet, vanity unit etc.: https://www.thefloorheatingwarehouse.co.uk/product/thermrite-dual-core-heating-cable/

Installation manual: https://www.thefloorheatingwarehouse.co.uk/wp-content/uploads/2022/11/ThermRite-In-Screed-Cable-Installation-Manual.pdf

 

I'll dig out some images of the house layout if you're interested.

For 2 current (sizeable) new builds I’ve just bleached the complexity, @JohnMo will be proud, and lost the AHU’s and FF UFH etc, but have advised both clients to install proper AC in the upstairs rooms which they’ve agreed to.

 

The sniff of heating is simple then, but cooling (both of these customers were very concerned about comfort and NOT being too warm during the summer months (all 2 of them 🤣)) so AC just seemed to tick all the boxes.

 

Not everyone is bothered about cooling, but when it is part of a remit conveyed to me, then I can’t just talk them out of it as it may only be used sporadically.
 

Not expensive by comparison, much easier to have room by room set temps, and the controls are just the remotes sat in their respective wall holsters or set on a piece of furniture, looking after the spaces accordingly.

 

The ethos is to leave these run on demand, so any change up / down in temp is countered as it happens; this should mean the units are only ever running very low and very quietly, doing to bare minimum duty. This should maximise longevity and reduce running costs, but summer cooling via the AC HP is likely to always be met if solar is present, so it’s offset so to speak. 

 

There are some very nice looking wall mounted units available, Matt white finish etc, so that’s the way forwards methinks. 
 

You just cannot beat having AC keep you cool in those stinking hot few weeks / summer months, and my sons attic room is just a joy during these times as I put AC up there for him (otherwise he’d be dead) and it’s defo high up the list when I finally do something nice for us, eventually……

[JohnMo]

32 minutes ago, Nickfromwales said:

There are some very nice looking wall mounted units available, Matt white finish etc, so that’s the way forwards methinks.

I lived in hot country where AC was a must, the thing that drove me mad after few months of the novelty, was the continues breeze.  But looking for something else the other day I notice Haier do a coanda effect wall mounted room units.  This encourages air the follow the ceiling (rather than being shot towards you) and then around the room when in cooling mode, heating mode does the opposite air is direct down to the floor

https://haierhvac.eu/sites/haierhvac-eu/files/2024-06/Haier_RAC_Catalogue_2024_ENGLISH.pdf

see page 31

 

If the aircon stuff is as good as the A2W appears to be it will solid and well made, plus a very competitive price point.