Hydronic heating - carpet?

Hi guys,

We are getting in slab hydronic heating to our entire first floor a majority is polished concrete; however two large rooms are carpeted.

I have received mixed guidance from hydronic installers as to whether there is any benefit putting it under the carpeted areas. Can someone please confirm if it still heats the room?
Really keen to hear from anyone who has hydronic in slab heating under a carpeted area too

Many thanks

Josh

It does. I sometimes wonder if these installers actually live with their own product. In case you’re wondering, it works under timber too, although you'd need to take precautions if your system can achieve a high water temperature.

Thanks mate, do you have it installed?

Yes. Five zones. Heat pump "fired". Carpet in three rooms, tiles and timber elsewhere. Nest thermostats for each zone.

Mate thanks - great news!

Do you think its worthwhile having split zones for the in-slab heating?

Right now I have a large open plan area, small powder room, laundry, and a decent sized lounge room and a Master Bedroom all on the first floor. Upstairs is three more bedrooms that will have split systems rather than hydronic.

Do you have experience with hydronic heating? I'm not being obtuse, but most Australians haven’t and therefore don’t know what to expect from it. Also, where are you building this house and is it making use of passive heating and is it thermally efficient?

We sunk $50K into our system, and I might not have done that if I'd considered it more.

Hey mate,

I’ve been in a house that had it, harmed the tiles and the ambient temperature felt nice. In short my wife gets cold - so has asked for it, in addition to split systems.
It’s costing us around 20k for the entire first floor of our proposed build in canberra.
So I’m tracking it’s a bit of a luxury, I’m just trying to make sure we don’t regret doing something later (additional insulation etc), or something pointless (like under carpet - if it did block the room from warming up).
In the attached photo, everything will be polished concrete except the lounge, master bedroom (carpet) and ensuite (tile). The slab should get some sun prior to lunch (north is the top right corner of the picture)

“Warmed the tiles”

I'm interested in the windows in the lounge and open plan area. Would you mind sharing the elevations of the north eastern and north western sides of the house? Also, are they shaded by neighbouring buildings or trees?

I live near Cooma, so our climate is similar to yours. Our Northern side is pretty much all glass and not shaded by anything. On even mildly sunny days in the middle of winter, the house is toasty. I spend a lot of time managing the temperature through blinds, awnings and opening windows, and we only ever use the hydronic heating when we have a succession of cloudy days - which is rare in our area and yours. Because hydronic heating takes hours to get to temperature, it’s possibly not the best solutions in that situation, but it’s what we have so we use it to the best effect we can. We are not unique in this regard. A family in town who visited our place during the early stages of there build at the request of their building designer who we know, have also found similar at their new rural home.

Since you have a nice northerly aspect to the main living areas of your house, you might be in a similar position. That said, every room and area to the south of you lounge, living and dining area will get no direct benefit from your orientation, so they will remain cooler.

Hey mate, that window in the lounge is meant to be 2m wide and 2.4 high, it will probably end up being 2.1 high though (just checked the window quote and they got the measurements wrong - so thankyou!)
But that’s a carpeted area and I expect that it will get some after lunch sun but due to the proximity of the neighbours and the Lt of the land, vegetation - I doubt any direct sun after 3-4pm.

Well, without knowing more about the design of the house (eaves, insulation, glazing, etc, etc) and based just on the floor plan alone, I would separately zone the open plan living area, the lounge, and the master bedroom+ ensuite+WIR. I wouldn't even bother putting coils under the hall, laundry and powder room, and I would definitely avoid heating the pantry.

Ahh ok, I will talk to the builder. My thought was to do the whole bottom floor except thale garage; to ensure the whole floor was heated. But I can definitely see your point reference the pantry!

In my humble opinion, going for underfloor hydronic heating, when you already opting for reverse cycle heating and cooling would be a bit overkill, esp, if you are not going for tiled floor to maximise the heat transfer. I would rather go with good insulation (up-spec wall and ceiling R), all windows double glazed with uPVC (or TB Aluminium if you can afford) and incorporate good solar passive design.
We have uPVC and timber floors with R2.5 wall insulation and R6 ceiling insulation and a mostly northerly opening big windows. Its been over a year we have been in our house and gone though all seasons, it is really warm and cosy in the cooler months and no problem walking bare foot on the timber floors. We have only used the heating or cooling for extreme few weeks of summer or winter, most of the time (like now) the house just manages itself. Having come to our new build from a non-insulated rental place, its amazing the difference what a good orientation and proper insulation can achieve, it is almost magic!

Cheers mate, we have polished concrete to the entire downstairs; just carpet to two rooms. But I appreciate your feedback; we’ve got the same insulation as you, decent orientation, but only double glazing - didn’t opt for thermally broken or upvc; so I’m hoping we will be fine.
I think my wife wants a little bit of luxury/overkill (she seems to get allot colder than me) in the heating department.
Where did you get your windows from? We’re currently looking at a Taylor’s windows for double glazing, but I’m not sure if they’re any good or not.

Sorry, I have to admit, I am a poor reader, didn't carefully read through this tread; if polished concrete it make sense, if you are going with HH then also make sure you have under slab insulation (basically XPS boards laid down before foam-work) and slab edge insulation as well, that will give you the most heat retention. Having said that if you are going with solar water heater, or solar powered heat-pump for heating up the hydronic system then a little bit of energy loss should be OK - I guess talk to your builder on cost and do a cost-benefit analysis.
In regards to uPVC, we went with a local supplier (https://malplas.com.au/) , it cost us around 30% extra compared to equivalent normal aluminium frames. The TB aluminium is much more expensive, I guess about 40-50% more.

As you are going with polished concrete, the hydronic system would really be a luxurious addition for sure! Certainly if you appreciate toasty warm under the feet.

For thermally broken aluminium windows in Canberra, have a look at ViewCo, who have a showroom in Canberra and a factory in Wagga.

I used viewco for my build in Canberra and can high recommend them

Thanks - have gotten into contact with them