In Floor heating

[sphelps]

I'd find a company that installs these kinds of systems and ask them, but I would assume if you have a general idea of what's needed to go bigger rather than smaller for the heating source. Heating systems work on a thermostat so if the heat source is a little big for the job it shouldn't really matter. The circulation pump will be a little more critical but if you can find out the recommended flow rate for the size piping you're using you should be able to simply multiply that by the number of pipes you're using.