Electric Underfloor Heating - AHT Heating

[andreas40]

Hi all, I am new to this and I am only posting my question after reading a bunch of threads regarding the electric underfloor heating. I am rennovating a large apt (230 m2) and I am looking into underfloor heating. I am between the conventional water pipe system vs the electric heating system.

My question is really if someone out there has used the AHT-Heating systems which seem promising and promise great energy savings (assuming a well insulated house). The edge of this technology is that it uses an amorpous alloy ribbon that increases the actual heat transfer area over more widely used wires and has a much lower profile of 20-30 microns.

Has anyone used this system? I would like to hear some comments on it.

Thanks for your input.

CQ

[andreas40]

Failed to mention their website

for those who would like to take a look. I am not marketing their products in any way. I am just trying to get some information on this technology from people who have used it. It's realtively new and not that many users out there I presume. Thanks again, CQ

[Fred]

The laws of physics tell me the amount of heat you get out is the same as the heat you put in. This sounds like snake oil. Go for the most reliable system. The idea of an "amorphous alloy" sounds very worrying!

[Grunff]

And what is the supposed result of using such a magical heat-transfer medium?

Any electric heating system will be 100% efficient at the point of use. They can't better that.

[Ian Stirling]

You might get marginally faster warmup, though I doubt it'd be measurable.

With the small caveat of heat-pump systems.

[andreas40]

The idea is that the alloy has no heat capacity at all and transfers all the energy given to it immediately. That resulting in fast results and no losses. They claim that in a well insulated house the real consumption is only 20% of the time the heating is turned on. So if you are running it for 10 hours a day, the consumption would only 2 hrs worth.

Also, the increased heat transfer area ensures more even heating.

Just adding what I have heard from the distributor and read from marketing docs. No real experience with the material.

[John Rumm]

With any electric heating system there will be no losses. The size of the heating wire is negligible compared to the thermal mass of the building (even a "slow" wire based system will be up to temperature in seconds, the house is at best going to take tens of mins to respond). So basically you can ignore all the marketing bull and get back to first principles.

If you house needs an average constant input of 5kW of energy to keep warm, then that is what it takes - the source makes no real difference. The cost of running any electrical system[1] that does that will be much the same.

[1] Someone did mention heat pumps, which will recover heat from outside and pump it in, giving and effective rate that exceeds the amount of electricity consumed.

This is more the key - good insulation will reduce heat loss grammatically. The same percentage savings would again be archived with any heating system though.

Apply some logic and you will see you have electric UFH. If that is your only source of heat it is likely to be pricey to run. Also look at the power requirements - you are talking about lots of floor area - have you worked out the power consumption for the house with it all running?

Have you done any heat loss calculations for the house? If not google back on this group for some information. That needs to be the first step so that you know what level of heating you are going to need.

[The Natural Philosopher]

Efficiency and cost has everything to do with the ratio of conductivity from the wire to where you need the heat, and from the wire to where you don't want the heat to go...it has nothing to do with the actual heating elements themselves.

Cost is related to the cost of the energy used, and the amount that DOES gate wasted via conduction paths elsewhere, and how big a surface area you have to keep heat way through and how much ofa temperature gradient you get across it.

All other things being equal, and in comparing wet:electric, mostly they are, your only variables are installation cost and energy cost.

Since electricity is about twice whats any other form of heating is, its a thumbs down for electric all the way.

The only time to install electric UFH on any appreciably sized area is, as with mains halogen spotlights, when you want to do a quick and very cheap job that will sell your house and leave the running costs with some other sucker.

[Tournifreak]

Not this particular system, but it sounds just like any other electric UFH system to me. Basicly the bottom line is not to do with energy transfer from the heater (whether it be electric wires or water-filled pipes) but the cost of the energy required. Using a gas boiler to heat water-filled pipes is still MUCH cheaper than electric heating.

For 230m2 I would say you are looking at a truly enormous electricity bill. Of course, you probably can't fit a wet system becasue it would entail removing all the concrete floors first. If you don't want rads, there are other options that are less intrusive but still a lot cheaper to run than electric-based heating. I have seen flat panel radiators that you then paint over so they're virtually invisible. Sorry, can't remeber where I've seent ehm though.

Good luck. And ignore the company's hype about specific heat capacity - completely negligable compared to the specific heat capacity of the floor!

Jon.

[Grunff]

I knew there'd be magic somewhere in there.

There are never any losses, all the heat generated by an element

*always* ends up in the surroundings.

I won't even pretend to understand that statement.

This may be true, but it depends on what the heating element is installed in.

[Guy King]

The message from [e-mail] contains these words:

So, where's all this free energy coming from? Or, to put it another way, where's all the energy that traditional systems consume going?