Adding a radiator-Pex?

Cyclist77

As I work toward the installation of the Weil-McClain CGa4 that will be used for our radiant floor heat system I am thinking of adding a radiator in our mud room as additional heat. Would running a pex line to it be a acceptable method?

mattmia2

It depends. oxygen barrier pex of the right size is probably fine for the piping but how are you controlling it and where are you feeding it from the system? If you use the mixed down water for the radiant then you have to size it to that supply temp, if you use the boiler temp water then it can be smaller but that may limit your options later if you replace the boiler with a mod con.

Cyclist77

ThThe new boiler is CI. My idea is a separate circulator before the 4 way mixing valve. And have it on a separate thermostat.

mattmia2

have to be careful with microzoning with that.

Cyclist77

Could you educate me on micro zoning?

Big Ed_4

I am thinking a panel radiator ? I would set it up with a higher supply water temperature then the radiant..Not sure how your system is pipe to tell you where to plug in….

mattmia2

https://forum.heatinghelp.com/discussion/comment/1851800#Comment_1851800

If you have a zone that is much smaller than the capacity of the boiler and that zone is calling alone then the boiler will short cycle unless you have a buffer tank or something that can modulate like a mod con. The boiler will heat to setpoint and shut down very quickly because there is little load to get rid of the heat that the boiler is making.

I assume you know how you will deal with mixing the water down to the temp the radiant zone needs and how you will protect the boiler from low return water temps.

Cyclist77

Thanks mattmia.

ThThe boiler will have a 4 way Tekmar Mixing Valve and if history is any indication this panel radiator will only be active when the whole system is running.

hot_rod

It was called a wild loop, a small zone that would run any time other zones would run, adjust the flow so it doesn't over heat the space. A panel radiator running the same mixed temperature, downstream or the 4 way would be the simplest.

Cyclist77

Hot Rod that would definitely be the simplest solution as I do have an extra S&R on one of the manifolds for that area. Just wasn't sure that the lower water temp would be adequate. But I suppose I could start there and change over to a separate circulator if it wasn't doing it's job.

I will just prep the boiler accordingly.

Thanks!

hot_rod

https://forum.heatinghelp.com/discussion/comment/1851855#Comment_1851855

its all about surface area, the larger radius, the lower the temperature they can run

mattmia2

if you design the radiator to use the water temp in your radiant loop then it will work with the temp in your radiant loop

Cyclist77

I may have a limiting factor as the area may eventually be turned into a laundry area. So planning is key!

hot_rod

walls and ceilings can be radiators also. Plates and pex is all it takes