Radiant Heating & Cooling Calculators

NOTE: For determining the amount of heating or cooling that can be provided by a radiant source, we have developed the following calculators. While they eliminate a chalkboard full of equations, it is important to understand how to use them and what the outputs mean. Feel free to play around with them but we suggest to have the Chiltrix engineering dept. comment/assist before you rely upon any calculations.

1. The first calculator “RADIANT” calculates the net radiant transfer per ft.^2 based on the emissivity and temperature of the radiant surface and, of the surfaces of the room to be heated or cooled. The radiant transfer values must be added to convection values to get a total transfer value. Note that all objects in the universe (>0 degrees K) continuously emit radiant energy. And all objects continuously absorb radiant energy. The calculator calculates and compares both the absorbtion and emission to provide the net energy transfer.
2. The 2nd calculator is for CONVECTION, as with the radiant calculator, this is not the full heating or cooling calculation, as the output will then need to be added to the results of the radiant calculator to get a total value.
3. The 3rd calculator, SURFACE TEMP, can be used to calculate a surface temperature based on a heating or cooling source (heat transfer plate temperature) and an R value of the materials that separate the room facing surface and the source.
4. The 4th calculator, CONVERT K TO R, allows you to find the R value of a material. While only some materials will have a published R value, nearly all materials will have a K value that can be found online. This calculator converts a K value to an R value.
5. The 5th calculator, DEW POINT, allows a calculation of dew point from a known RH% and temperature. This is important for understanding radiant cooling capacity of a system under various conditions.

TIP: The CXRC Radiant Cooling Calculator manual includes a tutorial with additional info on how to use these calculators: CXRC1 Radiant Cooling Controller Manual

TIP: In most climates, radiant cooling will need a dehumidifier in order to provide best comfort, and, to keep the dew point low enough to obtain maximum radiant cooling capacity. Note that radiant cooling generally requires a dew point controller to prevent unwanted condensation.