Solar Gain is Overheating my Radiant Infloor System. Or is it?

Recently I had to deal with the question of how do I deal with solar gain in my house where I have radiant in floor installed.

Radiant in floor is fantastic because it is comfortable, efficient, quiet and is one of the best ways to heat ( and sometimes cool ) your home.

The issue of solar gain comes up when you have a room full of glass with radiant in floor and people will complain that the radiant in floor is overheating the space making it uncomfortable

Is it really the radiant in floor that is the problem?

If i went into my kitchen in my house where I have lots of glass with no radiant heating and measured the floor temperature of the tile where my cat is sunning herself its going to be 80-85 degrees easy.

The sun is heating up the surface of the floor and I do not have any radiant in my Kitchen. At this point you are probably saying duh, we know that the sun heats up the floor. So in my kitchen where there is no radiant in floor what do I blame for the heat?

I think that the legendary Robert Bean says it best when he says ;

100% of all over heating and under heating complaints in homes heated exclusively with furnaces did not have radiant floor heating to blame.

It’s not the radiant in floor in combination with the sun that is causing my room to overheat it is simply the solar gain over heating the room.

So what is the solution to over heated radiant rooms? Good question! Open a window? Install better windows? Pull the blinds? Turn down the radiant in-floor in the rooms where you have significant solar gains?

Depending on how your radiant in-floor system has been installed it can actually help you combat solar gain. If you are able to set your system up for constant circulation you can move the FREE solar heat from the very warm rooms into some of the cooler rooms where it can be dispersed.

In my own home I am using the RAUpanel radiant in floor system from REHAU. It is a dry panel system which goes on the floor and that means that my solar gain issues are non existent. Unlike traditional radiant systems where it takes time for the slab to change temperature my RAUpanel system can adjust for solar gain in as little time as it takes me to brew a cup of coffee and drink it.