hydronic floor heating - what do you know??

does anyone know much about hydronic floor heating?? I have only just heard about it for Australia (I had thought it was a Europe only thing) and it is something I am interested in knowing more about re cost, efficiency, effectiveness, hassle, etc.

It would be good to hear from people who have considered doing it. If you did go ahead with it, what tipped you over? And if you didn't go with it, why not?

All discussion encouraged
Thanks
Peta

Looked into it and decided against it because:
1. I like carpet on the floors of bedrooms and having the heat below the insulating layer of carpet didn't seem to be a good idea.
2. I believe it is not very responsive in that it takes a while for the heat to come through.

we were thinking in larger areas like our tiled open plan kitchen-dining-family room + entry hall which is kinda largish (>90sqm). I agree that it seems kinda pointless underneath carpet.

I had read that it takes 1-2 days for the floor to be heated with a hydronic floor heating system but it's also not the kinda system where you turn it on and off like a heated towel rail. For example, if you want the bathroom floors to have instant heat, I think I would go for an electric floor heating system (switch near the door), rather than a hydronic floor heating system. But for large area floor heating, you turn on the hydronic system heating at the beginning of winter and keep it going until spring/summer comes to town. Well, that's my impression. Not sure if I've got that correct, which is why I'm asking.

I've been looking into this for our new build. There are two types of hydronic- in slab and panels. To add to bashworth's comments, if you have in slab heating, it is inefficient (but possible) to have a carpeted floor. Also, if you're looking at timber floors, you need to make sure that they are rated to handle hyrdonic heating. Tiles are best for hydronic heating

Just to confirm what you said, with the in slab systems, you need to pretty much leave them on 24x7. Once the slab is warm, they don't require much energy to keep it warm as they rely on the thermal mass of concrete, so are very efficient. I lived in London for a while, and our boiler broke in the middle of winter. It took a few days for the house to cool down.... then a few days for it to heat back up when the boiler was fixed.

Another option rather than in floor heating is to get panelled hydronic heaters. You'd need these for a second storey. These are more common in older European homes. The only problem with these is that the panel takes up valuable wall space (although you can get some pretty stylish and unobtrusive wall panels these days).

We lived with electric slab heating in a rental for a year. It is much more expensive than hydronic to run and I wouldn't choose it for that reason, but we did find it amazing. We had carpet and it was so cozy all through winter. We didn't have any heating upstairs and the heat rose to make it very warm there also.

We decided against hydronic for our build based on cost of installation but also on the lack of flexibility. I want heating on those single cold days in summer, and I don't want to overheat at night.

Hi Peta, just checking in so I can follow. V interesting subject.

I have just joined this forum ( see intro ) partly in response to the query re; hydronic underfloor heating and carpets. Central heating is a relatively new concept here in NZ too. Following extensive research, mainly from UK/US websites, we have installed hydronic underfloor heating under all tiled areas of our new build, and in carpeted rooms we have opted for radiators. I was not convinced the underfloor heating would be effective under a densely woven carpet and quality underlay. I also like the concept of enjoying the heat emanating from the radiators - with the bonus of the radiators making handy sock dryers! Hopefully we have made a wise decision - won't know until next winter.

Sorry I've posted this twice ( getting the hang of things )

We have in slab heating in our polished concrete floor with hydronic heating panels upstairs. Downstairs has been a toasty 20 degrees constantly and the floor took 2 days to warm to 20 degrees and leave it on 24/7 at 20 degrees. For upstairs, we switch on the panels to 21 degrees for the heated towel rails at about 630pm and then turn it back down to 18 degrees for bedtime and then switched off in the morning.

I should add that we have invested in geothermal technology for the above.

I have yet to receive a power bill though as this is our first winter.

Hi. Thanks for that. What do you mean when you say you have "invested in geothermal energy". How are you sourcing the power for the heating and what do you expect it to cost?

Go through the website of Direct Energy (google them - a Victorian company) for geothermal technology - too technical for me to explain here. They were our suppliers.

In summary, a compressor draws the earth's energy to power our heating and hot water. We have 2 compressors and 2 tanks that took up quite a bit of corridor space outside the house.

As for costing, well, let's just say I opted for the technology over interior decorating. The technology is supposed to work for > 10 years. It's american technology and depending on your house size, copper loops are used and these are not cheap though the AUD-USD exchange rate might be slightly in your favour.

We lived with floor heating for 20 years in the USA which we called radiant heating - water pumping through copper pipes embedded in the concrete slab.

How I miss it - it was the best form of heating we have ever experienced.

We had an auto timer which put it on at 4 am to 7 am and then 4 pm to 7 pm - these 6 hours a day were sufficient to get us through a very cold winter.

We would consider it again if there was a system of linking solar hot water being pumped through the copper pipes.

When we remodeled we ripped up all the carpet and put in terracotta tiles. The house became even warmer - we didn't realise how much heat was being lost in the carpet.

When my sister came to visit she fell in love with the heating system and had it custom built for a house in South Australia. It's still going well after a decade and everyone comments on the cosiness of the house.

Just bumping this old thread to see if anyone has any recent experiences with hydronic floor heating? I know technology can change rapidly and I'd love to hear if people are building with this heating now in 2014. Thanks

I am planning to install hydronic heating. I understand how it works; have enjoyed it for many years in Germany, and simply love it.
There are a few things that need to be understood to enjoy this system.
Get an installer who knows hydronic heating back to front.
Usually the decision is made to late in the building process.
In-slab is not the best way of installing such a system, as the slab needs to be insulated against heat loss, hence, the pipes go onto the slab after insulation is put on the slab.
The main disadvantage is cost; it seems it costs at least double what it costs in Germany.
Builders shy away from such a system (never done, have not clue, too scared = charge an arm and a leg).
Installers are usually no trained; most German (and in other countries) require the installer to attend training courses, which they don't due to the cost involved. This means they can't get the gear form these comapnies and resort to cheaper components, which do not provide the performance; on top of that, short-cuts are being undertaken (such as inferior insulation, inadequate manifolds and circulation pumps), leading to a significant underperforming system.
It is not a system that is being switched on when required, but requires a lead time, which is usually achieved through some timer and int/ext temperature control.
It is far more efficient than any other form of heating -- also being the most comfortable heat as Amadio commented.
Carpet does not matter in the equation WRT efficiency and effectiveness; carpet may present a problem for allergic people, due to raising dust particles.
The heat source can be anything, including solar hot water.
Due to the significant cost, lack of knowledgeable builders, architects, engineers, and installers, hydronic systems are given the thumbs down in Australia.

My system will be installed in a solar-passive house, above concrete slab, after insulation, covered in self-levelling screed, reinforced with steel mesh. A variety of floor coverings will be installed. The system is computer controlled, including preset schedules for weekdays, holidays, weekend schedules, etc. A percentage of heat will be generated by solar hot water, the rest will be surplus energy from the solar PV system. If required a wet back on a wood heater can contribute to the heating.
And yes, I am owner-building... simply to get the quality I am after in the build.