Hi All-
I know this thread is old, but being an electric radiant heat manufacturer, I wanted to clear up a few things in case anyone else stumbles on this.
1. Electric baseboard heat, and in floor radiant heat are VERY different. Baseboard heaters are very ineffective because they are a very local heat source that may have fan (may not) but need to move that heat around the room and they don't have a good way to do it. Just like a forced air system, you are dumping a lot of heat into a room in one spot and then having to stir the whole room up to distribute the heat.
Electric in floor heating spreads the heat source out across the room, and then directly heats the occupants and surfaces. If you buy a 1500W wall heater, that is an equivalent amount of heat as to what you would have under 100 square feet of floor. Then you read the floor temp (not the air temp) and so the system will only actually run a fraction of the time. Much less than the wall heater.
There are a number of responses above that seem to comingle "electric" with radiant heat.
2. Hydronic Vs Electric to heat a space - There are two common methods to heat with in floor heating. Water pipes (hydronic), electric wires (electric). Hydronic can be really good for large areas as the cost of PEX tubing is low and you can manage the power requirements more easily. However it does take a lot longer to move the temperature of the space and there is a higher initial system cost than electric. There is also the ongoing maintenance of the boiler. Typically hydronic systems output about 25-35 BTU and the heating tubes need to run through some form of thermal mass. Typically self-leveler or inside of a slab. This is why it takes so long to get to temperature as you are moving the temp of the entire mass. Electric systems (at 15W psf) output about 51 BTU per square foot and can sit just underneath the flooring surface so you are able to put more heat into the room faster and therefore move the temperature of the room much faster.
3 - While it is true that hydronic systems and most electric systems could require the whole floor to be removed in the event of an issue, that is not true of certain custom electric heat mats. If damage to the system does occur there are systems (at least one that I personally am familiar with) out there have an easy way to pin point the issue limiting the removal to a tile or two.
4 - And lastly there was a comment about big stackups and vibrations due to movement. Luxury motorcoaches have been using in floor heating for decades. They shake like a 5.2 earthquake and the systems hold up fine. Since they need to be as light as possible the best systems are about 1/8" thick and can be encapsulated in thinset with a 3/8 notch trowel to reduce any extra work, height, weight and cost.
Thanks. Happy to chat more about it.
