INDEX
Getting Started
Heat Load
.....heat loss basics
Floor Output
Floor Covering
Floor Surface Temp.
Average Water Temp.
Supply Water Temp.
Tube Selection and Size
Tube Spacing
Total Tube Required
Tube Circuit Length
Number of Circuits
Actual Circuit Length
Flow Per Tube
Pressure Drop
Summarize Circuits
System Flow
System Pressure Drop
How Much Heat?
[if you have a heatloss calculation skip to Floor Output]
The first essential bit of information you will need is the amount of heat the floor will be expected to produce. This is determined by estimating how much heat the building will lose. Heat loss is calculated for the coldest design temperature your building will experience during the winter.
Heat Loss
Whether you have one room or a mansion to heat, heat loss is calculated the same... one room at a time. You simply calculate the heat loss for each room and add them up as you go. You need to know the heat loss of each individual room to properly size the radiant system. Heat loss calculations are not difficult to do, they are just time consuming. It is not an exact science and there are a lot of judgement calls to make along the way. The idea is to get as accurate a prediction as practical of the amount of heat needed to maintain the space.
Heat Loss Calculation Sources
If you donʼt know how to do heat loss calculations or simply donʼt want to do them, here are some resources.
• Designer or architect who designed the building
• Local Utility Companies will often do the heat loss calculations if you supply the plans
• Equipment supplier where you will be purchasing the radiant materials
Buildings heated with radiant floors often have lower heat losses than buildings with conventional heat, therefore conventional heat loss calculations may over estimate the heat loss of a radiant heated building by as much as 30%. Keep this in mind when using a heat loss supplied by a source that is not familiar with radiant floor heating.
Do-it-yourself Heat Loss
If you would like to do your own heat loss calculations, there are a number of good programs and books available.
A very simple procedure is presented here which will get you in the "ballpark".
