Radiators Sizing to Zero, Manual Sizing Not Providing Heat

[dnelson]

I have a system set up in ApacheHVAC and would like to use radiant heat for the perimeter zones.

Here's what I've done:

Set up a number of constant speed, single fan, dual duct systems with no radiant heat. No big problems. Lots of small ones, but I got through it. The system was autosized and works fine.

I was told that there is radiant heat in the building and proceeded to add raditors to the perimeter zones that have it. Autosize was checked, I ran system sizing, and the radiators were sized to zero Btu/h.

I tried manually sizing a couple of radiators, but that does not work either.

What am I doing wrong here? I would like the hot deck of the dual duct system to provide reheat (and maybe a little extra heating) and the radiators to provide the majority of the building heating.

Thank you.

[macleodd]

It sounds as if you are not using a Prototype system (i.e. one with grey top bar).

To be able to autosize a room unit *load* as well as the unit's air & radiant temperatures, you must have such a system (imported from the library) as your starting point.

Regards, Donald