DIY radiant floor tubing installation video

Of the different types of radiant floor heat, the efficiency isn’t affected as much by the delivery system, meaning whether it is an air heated floor, electric mat radiant floor, or liquid glycol hydronic radiant floor. What matters most is the amount of insulation below the floor and the fuel source, whether that’s gas or electric. You may have seen this page but have a look if not, there is a comparison of the pros and cons of the different systems – 

Which is the best type of radiant floor?

To give a quick summary though, forget gas and just think electric – the efficiency of electric resistance heating doesn’t change based on how it’s delivered. A baseboard heater, hair dryer, toaster, boiler or electric mat floor generate the same amount of BTUs per Watt whether you are heating a wire, or a wire heats air or water and then forces it through tubing in a floor. So hydronic, air heated floors or electric mats are effectively the same in efficiency. 

The differences are subtle, but in the case of the air heated floors, the heater is in the floor itself so all the heat is contained in the floor rather than escaping into the mechanical room where the boiler and manifolds are all exposed. So the heat is contained in the floor, but also distributed a bit more equally throughout the house. It just ads abit of comfort and balances the heat better through the house.

Air also has a lot less latent heat in it, so when the thermostat hits the desired temperature and shuts off the heat, it will stop heating. A hydronic floor has so much heat in the water that oftentimes you can overshoot the thermostat setting and overheat as it is released. Air tubes are also a bit easier to install, and less risky to damage during install or afterwards. If you pierce a pex tube in your floor and don’t know it and fix it, the system won’t work. If you put a screw into an air tube it makes no difference.   

Thanks for your question, and I would start here in general terms of efficiency in heat delivery - there is no great difference in the energy efficiency between air heated floors or hydronic (liquid) radiant floors, at least when they are heated with the same fuel. Meaning – a boiler heating water that is circulated through radiant tubing in a concrete floor will not be any more or less efficient that a boiler heating a water coil that blows air through a floor.

The fuel source (gas, electricity, propane etc) will affect cost and efficiency, but differences in how you deliver heat isn’t as big a factor in determining efficiency. This page discusses the differences and pros and cons of each system – 

Radiant floors heated with air tubes

Moving into a solar solution though and choosing between a solar water heater and a solar air heater, there you would for sure have more variables in terms of the initial cost of the system, return on investment time, maintenance and lifespan. 

I assume you saw our page on solar air heated radiant slab on grade floor. I would personally lean towards that because they address a lot of the issues that come up with solar thermal water heaters – read more here, which can have a lot of maintenance issues. The thermal solar air panels we installed in that prefab kit house obviously don’t leak water, freezing is not a concern, and even summer overheating has been solved because that system has been adapted to generate solar hot water in summer in part to cool the system.

Solar thermal water heaters can, in a bizarre twist, need to be covered often during summer to avoid overheating. I hope this helps, check out those pages and if you have more questions let us know, but include your climate zone as well and we can better help you decide.