Observations on need for heating upstairs

[Post and beam]

Prior to starting our build and when deciding on what and how we would heat the house we were told more than once that separate heating upstairs was not required.

Ours is not at Passiv level, it does have a .11 roof, .12 floor and .15 walls.

We have UFH downstairs and a total of 6 radiators upstairs. All on a single unmixed heating zone. Radiators were sized for the expected heat loss and flow temperatures.

 

The bedrooms are at about 18.5 - 19 degrees which feels a little chilly to me.

Heat does not appear to reach upstairs very effectively. We have a centrally located 180 degree return staircase. There is a noticeable gradient in temperature as you get to the landing, which surprised me.

Now, i fully accept that our single zone design with a flow temperature that has not so far ever got above 38 degrees even at minus 5 in December is not best suited to radiators upstairs.

But that is not the point. If we had gone without radiators at all upstairs  we would be in trouble .  

For those contemplating going without any heating upstairs i hope this little tale is helpful.

keith

[crispy_wafer]

Useful to know.

 

What's the plan going forwards, will you make any changes to the current setup in any way, I wonder if fan coil rads would make any difference to the feel.

[PhilT]

18 minutes ago, Post and beam said:

We have UFH downstairs and a total of 6 radiators upstairs. All on a single unmixed heating zone. Radiators were sized for the expected heat loss and flow temperatures.

how do you operate your daily schedule; on all the time at one temp? Any set back? Any switch off for a period of time?

[Post and beam]

Based on a previous discussion in another post i did wonder about a mixing valve. There is nothing like this currently in our setup. 

[Post and beam]

2 minutes ago, PhilT said:

how do you operate your daily schedule

WC @ .45, on all the time.

[Nickfromwales]

24 minutes ago, Post and beam said:

Prior to starting our build and when deciding on what and how we would heat the house we were told more than once that separate heating upstairs was not required.

Ours is not at Passiv level, it does have a .11 roof, .12 floor and .15 walls.

We have UFH downstairs and a total of 6 radiators upstairs. All on a single unmixed heating zone. Radiators were sized for the expected heat loss and flow temperatures.

 

The bedrooms are at about 18.5 - 19 degrees which feels a little chilly to me.

Heat does not appear to reach upstairs very effectively. We have a centrally located 180 degree return staircase. There is a noticeable gradient in temperature as you get to the landing, which surprised me.

Now, i fully accept that our single zone design with a flow temperature that has not so far ever got above 38 degrees even at minus 5 in December is not best suited to radiators upstairs.

But that is not the point. If we had gone without radiators at all upstairs  we would be in trouble .  

For those contemplating going without any heating upstairs i hope this little tale is helpful.

keith

Amen.

 

A handful of folk on here may say they’re ok without FF heating, but a heck of a lot of folk wouldn’t be so fast to agree, now yourself added to that number.

 

@Post and beam, you can easily add a mixing set to the UFH manifold, and then turn the flow temp up to say 45° to see if that perks the rads up a little. 
 

The caveat is that they’ll then possibly need to have TRV’s but that’ll be down to trial and error.

 

You can jump the flow temp up in 2° increments until content. The Ivar blender starts at 20°C and goes to 60°C, and is very accurate.

[Nickfromwales]

Thanks for the thread though, as this is a great bit of balance to what seemed a very one-sided subject .

 

My rethinking around this, I’ve reassessed heating and cooling quite intensively over the last 6 months, is that AC (for very gentle heat or effective cooling) on the first floor makes more and more sense every time I look at it.

 

Even @Jeremy Harris ended up retrofitting AC to get his home tolerable. 

[Post and beam]

15 minutes ago, Nickfromwales said:

Thanks for the thread though, as this is a great bit of balance to what seemed a very one-sided subject .

Thanks dude, that was the motivation.

 

Regarding the Ivar mixing valve option. I am not sure i have the space to install one as it happens.

Therefore a review of my radiators to move them around and fit a couple of larger ones might be the thing to do. K3 instead of K2 perhaps. 

[RedRhino]

59 minutes ago, Post and beam said:

Prior to starting our build and when deciding on what and how we would heat the house we were told more than once that separate heating upstairs was not required.

Ours is not at Passiv level, it does have a .11 roof, .12 floor and .15 walls.

We have UFH downstairs and a total of 6 radiators upstairs. All on a single unmixed heating zone. Radiators were sized for the expected heat loss and flow temperatures.

 

The bedrooms are at about 18.5 - 19 degrees which feels a little chilly to me.

Heat does not appear to reach upstairs very effectively. We have a centrally located 180 degree return staircase. There is a noticeable gradient in temperature as you get to the landing, which surprised me.

Now, i fully accept that our single zone design with a flow temperature that has not so far ever got above 38 degrees even at minus 5 in December is not best suited to radiators upstairs.

But that is not the point. If we had gone without radiators at all upstairs  we would be in trouble .  

For those contemplating going without any heating upstairs i hope this little tale is helpful.

keith

Do you have MVHR? That helps mix temperatures. It also indicates that the house was built with airtightness in mind : )

 

We don't have upstairs on our two upper floors but we do have MVHR. Sleeping in 18c is fine, maybe not sitting at a desk working. 

[Nickfromwales]

8 minutes ago, Post and beam said:

Thanks dude, that was the motivation.

 

Regarding the Ivar mixing valve option. I am not sure i have the space to install one as it happens.

Therefore a review of my radiators to move them around and fit a couple of larger ones might be the thing to do. K3 instead of K2 perhaps. 

Post a pic of the manifold, showing above / below / immediately surrounding space. Doesn’t have to be directly connected, but needs to be close ish. 

[Bramco]

Not sure I agree @Nickfromwales.  Although all of this is about personal preferences.  Ours is an MBC build, you've worked on a lot, so you know what we have. 0.14 walls and vaulted ceilings and a passiv slab 0.1.   We are fully triple glazed but only 1.2 for the glazing (a lot of aluminum framed sliding doors). We also have triple glazed roof lights. Each bathroom has electrical UFH and heated towel rails (although we never use these). Two bathrooms on the 1st floor. And the ground floor is probably 2/3 of the total floor m2. MVHR of course and low ac/hr. We put in enough suitably positioned electrical points to be able to add supplementary heaters in the 1st floor bedrooms but have never had to fit these.  Our heat loss calcs came to 6kW. 

 

We only heat during cheap rate, so a maximum of 6 hours into the UFH in the slab from a (max) 9kW ASHP but this is enough to heat the house for the rest of the day. Bedrooms are about 18C which for us is fine. Living space is 20.5 to 21.5.  And when it's really hot, we use the ASHP to cool but that's only a few days a year. Having the sliding doors/rooflights open seems to keep things OK.  So we're a big vote for not needing heat/cooling on the 1st floor.  As for AC, it would have been a pain to fit and they aren't great to live with - draughts, noise etc.   

 

@Post and beam   is your UFH in a screed, or in a passive slab like the MBC slabs?

[Nickfromwales]

14 minutes ago, Bramco said:

Not sure I agree @Nickfromwales. 

 

14 minutes ago, Bramco said:

Bedrooms are about 18C which for us is fine.

That’s cold, and it would drive me crazy. At 19° I’m looking at my room stat and asking WTF.

 

14 minutes ago, Bramco said:

Although all of this is about personal preferences.

Absolutely!

 

This is why, for every new client, I start with a blank bit of paper. 
 

I don’t create ‘other people’s homes’, I create homes for the intended occupants and take my lead from them.

 

Heating on the FF is just a thimble-full, when required, but cooling is a very different issue altogether. 
 

At 21.5° I know my room is too hot, at 22° I want to kill.

 

Successfully managing this hysteresis and matching the occupants preferred ambient needs control, and the sun has a huge effect on the sums.

 

Solar reflective glazing is a huge asset here, but then folk will quickly moan about needing heating to offset the lost solar gain. 
 

The cost and impact of active cooling (by automation or human manipulation) outweighs this many times over.

[Post and beam]

21 minutes ago, Nickfromwales said:

Post a pic of the manifold

Will do when i get home later.

[Post and beam]

34 minutes ago, RedRhino said:

Do you have MVHR? That helps mix temperatures. It also indicates that the house was built with airtightness in mind

Yes. We have a 1.4 reading on air tightness from Aerobarrier.

 

24 minutes ago, Bramco said:

is your UFH in a screed

Yes it is. 75mm, why?

[Bramco]

11 minutes ago, Nickfromwales said:

At 21.5° I know my room is too hot, at 22° I want to kill.

Maybe we're just more tolerant than you  😉
 

11 minutes ago, Nickfromwales said:

Solar reflective glazing is a huge asset here, but then folk will quickly moan about needing heating to offset the lost solar gain.

We have both overhangs and external blinds on the south facing sliding doors.  Which means little solar gain in the summer. But plenty if we need it in the spring and autumn and plenty in the winter when it's not cloudy.

Probably the worst thing for most people is that they haven't any experience of what to design in - in our case that was certainly the case!  So it's serendipity that the blinds were a great choice, as were the rooflights and sliding doors for managing things.  We did do a lot of reading around heat loss and the need/or not for heating on the 1st floor and as I said made provision for supplementary heating but haven't needed to install it.

[jack]

Just before Christmas, we passed our 10 year anniversary in an MBC house.

 

Overall, we're very happy with the decision to not have heating upstairs. My wife would probably prefer things a little warmer in the bedroom(!) but honestly, it's fine.

 

Bedrooms rarely fall below about 18.5 degrees, and I have our heating system (UFH downstairs, single zone, polished concrete on insulated raft) set to come on if the upstairs temp falls below that. Currently the kitchen slab is 21.8 °C and the upstairs hall is 18.6 °C. 

 

My main regret is not putting in some form of UFH in the bathrooms. We even designed in dropped joists in the bathrooms to allow for insulation and flooring build-up, but in the end decided to save our pennies. It's not that the bathrooms are particularly cold, but the tiles feel a little chilly underfoot when upstairs is at its lowest temperatures. 

 

We ended up retrofitting IR panels to the ceilings. They help, but they're definitely not as good as UFH would be. We probably spent quite a bit more doing this than if we'd just put in electric UFH mats during first fix.

If I were doing it all again, I'd definitely add UFH of some sort to the upstairs bathrooms, but would not add heating anywhere else.
 

I would, however, consider installing air conditioning for summer. After a long run of hot days, it gets very warm upstairs. That said, I think purge ventilation could be a good alternative or complementary strategy if you don't live in a noisy area. Best to add retractible insect screens to bedroom windows so you can open them as soon as the temperature outside drops below the temperature inside, and ideally add a central openable rooflight to take avantage of stack ventilation.

[Bramco]

4 minutes ago, Post and beam said:

Yes it is. 75mm, why?

Just wondered if being in a screed meant the floor didn't retain the heat you put into it as well as a passiv slab should (and in our case seems to do). The MBC slabs are 150mm over 300mm EPS

[Bramco]

2 minutes ago, jack said:

We probably spent quite a bit more doing this than if we'd just put in electric UFH mats during first fix.

 

We built after you @jack and the advice then was to fit electric UFH in the bathrooms which we did and yes a warm tiled floor is well worth the small extra costs.

[Nickfromwales]

20 minutes ago, Bramco said:

As for AC, it would have been a pain to fit and they aren't great to live with - draughts, noise etc.   

Modern, domestic AC is none of these. Nobody would ever sell one if they were   

 

For 2 current live projects, one MBC ph TF and one (TBC) Nudura ICF I’m specifying AC on the FF, with wall mounted units being suggested (for the first revision for discussion). Also for cost reductions and simplistic installation, integration, and maintenance etc.

 

Cooling is part of each clients remit to me, so my job is then to find the best units, at the best price, with installation methodology that ensures maximum longevity and minimum nuisance to the occupants. Sizes will be considered (over) to get the units to be near zero impact (audibility etc). 

 

I recall staying in hotels pre / post Covid, one quite small room, and the AC on the wall doing its thing. An occasional waft (no noise or draughts) as the output was nearly fully modulated, and I slept like a baby in a perfect ambient, with the unit offering surprisingly little sound. It was wonderful, plain and simple.

 

Very apparent that the room had AC, as the unit was gloss black lol (maybe not a good choice for an otherwise lightly decorated room) and it was less than 1m from the bed, but it was an asset for sure. 
 

My plan is to set the units as far away from the bed and as high up as I can get them, so the modulated output is of no nuisance whatsoever. The focus will be on cooling the room, not the occupant. One will service the other, indirectly, by design.

 

In reality, us humans will tolerate a fan blowing directly onto us if it makes us cool, think desk or pedestal fans, so a near silent AC unit will simply not offend.

 

This is more of a storm in a teacup than it would actually be in real life.

[Nickfromwales]

5 minutes ago, Bramco said:

Just wondered if being in a screed meant the floor didn't retain the heat you put into it as well as a passiv slab should (and in our case seems to do). The MBC slabs are 150mm over 300mm EPS

100mm? Thickening over ring and intermediate beams.

[Bramco]

From the contract, so unless they shortchanged us.....    And the ring/intermediate beams should be 350.     Also noted that our vaulted ceilings are 0.1, not what I said earlier.

 

[Nickfromwales]

20 minutes ago, Bramco said:

From the contract, so unless they shortchanged us.....    And the ring/intermediate beams should be 350.     Also noted that our vaulted ceilings are 0.1, not what I said earlier.

 

My bad! I was thinking of another job. 
 

Too many plates spinning atm  

[Post and beam]

50 minutes ago, Bramco said:

Just wondered if being in a screed meant the floor didn't retain the heat you put into it as well as a passiv slab should (and in our case seems to do). The MBC slabs are 150mm over 300mm EPS

It does, but thats not relevant to my original post. 

[Dillsue]

5 hours ago, Post and beam said:

Regarding the Ivar mixing valve option. I am not sure i have the space to install one as it happens.

Therefore a review of my radiators to move them around and fit a couple of larger ones might be the thing to do. K3 instead of K2 perhaps. 

Get the rads sorted out. If you turn up the flow temp you'll be paying extra for the life of the house. A reshuffle of the rads you've got and one or 2 new ones will sort the heating for the life of the house.

 

If the rads you've got now aren't heating the upstairs enough then go back to basics with a check on room heat loss calcs and that the correct correction factors were used to size the rads for the design flow temp you want. Something has gone wrong if your rooms aren't getting up to temp and your really want to find out why

[Post and beam]

6 hours ago, Nickfromwales said:

Post a pic of the manifold, showing above / below / immediately surrounding space. Doesn’t have to be directly connected, but needs to be close ish. 

Here are pictures of the manifold.