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
BASIC HEAT LOSS CALCULATIONS
"big or small, just take it one room at a time"
There are four things you need to know to be able to do a simple heat loss calculation:
1. Outdoor design temperature
2. Indoor design temperature
3. U-value of the partition between the two
(1 divided by the R-value = U-value; for example: 1 divided by R-19 = U-.05)4. Partition area in square feet
You simply repeat the same calculation for each wall, ceiling, floor, window and door which is exposed to the outside temperature.
STEP (a) -
Indoor Design Temp - Outdoor Design Temp = ∆T (temperature difference)
example: 70˚F subtract -10˚F = 80˚F ∆T
STEP (b) -
Partition Height x Partition Width = Area
example: 8' wall height x 24' wall width = 192 sq ft
note: if the partition is a wall, be sure to subtract the area of any windows or doors and figure them separately
example: 192 sq ft - 16 sq ft - 21 sq ft = 155 sq ft
STEP (c) -
Find the U-value of the partition. [click for U=value table]
example: a 6" wood frame wall with fiberglass insulation has a U-value of .053
