Heat Loss Calculator Help Page

Radiant Infrared Heat Loss Calculator Help Page

This help file will explain what is expected as input from the user for every prompt in calculating heat/loss.

All data items (blanks) will have a default except the "Prepared For" and "Prepared By" blanks. The user can override (change) any data blank. There is a look-up table for construction material "U" values. All data blanks need to be completed, even if the value is zero. For example, if there are no windows in the building, enter zero for the "Total Area of Windows."

All values may be changed anytime before creating the heat loss analysis report, including the "Total Heat Loss" section, but the values that you enter will be used in the final report. For example, if the program calculates a heat loss of 1,000,000 BTU's and you have wood or dirt floors, you need to double the heat loss, so you can enter 2,000,000 into the "Total Estimated Heat Loss" blank. Now when you create the report the 2,000,000 value will be used in the report.

Prepared For

This should be the name and address of the organization for which you are preparing your analysis. This should be entered using upper and lower case letters, the report will print exactly what you enter.

Prepared By

This should be your name and address, entered exactly as you wish it to be on the final report.

Winter Design Conditions

"Winter Design" refers to the average, outdoor "winter" temperature for a particular city, or nearby area. The "indoor" temperature is the indoor design base, i.e., the thermostat temperature setting needed to be comfortable with a typical forced air heating system -- available in increments of 5° F. (55, 60, 65, 70 and 75° F.) Our program will automatically calculate the "Temperature Difference" blank. Do not override this value.

The "Degree Day Information" refers to the number of degree days for a selected city at the selected indoor temperature. Please choose the city closest to the building location. You may click in the box and "pull" the scroll bar on the right to find your location faster.

The fuel information is used to do a cost analysis between infra-red heating systems and conventional heating systems. The cost of fuel refers to the cost of a therm for natural gas, and the cost of a gallon for propane.

Building Specifications

This section will process all of the information needed to calculate the estimated heat loss of a building. The first prompt will fill in default "U" values for the different parts of the building. The default "U" values can be used if you don't know the actual "U" value for each material. There is also a "U" value look up table, which can be accessed by clicking on the "U Factor" link.

Exposed Walls

This value is the total length in lineal feet of outdoor, exposed (not heated walls).

The wall height is the height of the building walls, (not the heater mounting height).

Exterior Windows

This is the total area of all exposed windows, please enter the value in square feet.

Exterior Doors

This is the total area, in square feet, of all exposed doors, including large overhead doors. Use the "U" value of the doors with the largest areas.


This should be the total area of the roof, in square feet.


This will be the total lineal feet of the perimeter of the building, in most cases this will be the same value as the Exposed Walls. If the floor is wood or dirt, you will have to manually double the heat loss calculations in the "Total Heat Loss" section.

Infiltration Analysis

Outdoor air enters a building and displaces a corresponding volume of indoor air by means of either "gravity" (natural, atmospheric forces) or "mechanical" ventilation loss (exhaust fans).

Gravity infiltration is measured in number of air changes per hour. If you are unsure, select "Low", "Medium" or "High" from the choose list and the value will be filled in for you. For example, if you select "High" the value will be updated to 2.0 air changes per hour. If you have more than that, simply type over the value in the blank.

Mechanical Exhaust is measured in cubic feet per minute (CFM).

The larger of either "gravity" or "mechanical" infiltration rates is automatically added to the preceding total transmission heat loss calculation to arrive at a Total building heat loss.

Total Heat Loss

This section only requires the click of the "Calculate" button. The three blanks will be filled by the program. The "Transmission Heat Loss" is calculated from the information provided about the building,. The "Infiltration Heat Loss" is the additional heat loss due to infiltration. The "Total Heat Loss" is a sum of the other two values. If you wish to increase or decrease these values for some reason, simply type over the value and the value you entered will be used in creating the report.

Equipment Sizing

These blanks refer to factors which require an increase in the total heating equipment capacity to accommodate special building conditions. For example, if outside air needs to be ducted to a burner for its combustion air (instead of souring combustion air from within the heated room), the capacity of this burner is increased by 10%, when you click "Yes" for "Are you using outside air for combustion?"

The mounting height of a radiant tube-heater can have a similar effect. For every foot of mounting height over the optimum of 15 feet, our program adds 1% to the Total Heat Loss calculation. Simply enter the mounting height in the appropriate blank.

Annual Fuel Cost Comparison

The Heat Loss rogram will process an Annual Fuel Cost Comparison for Forced-Air heating equipment and our gas, radiant Tube-Heaters. This programs incorporates the industry-recognized "10 Degree Set-Back Rule" for estimating the annual fuel costs for radiant Tube-Heaters, which applies as follows: if the thermostat setting must be 70° F. for personnel comfort with forced-air heating, these personnel would be equally comfortable with our gas, radiant Tube-Heaters at a 60° F. thermostat setting.

Creating the Report

Now that all of the blanks have been filled in, simply click on the "Click Here" button, and a new window will appear with the heat loss analysis report. To print the report simply click on the printer button, or go to "File" on the menu bar at the top of the window, then Print, on the menu bar at the top of the window. If you are not satisfied with the report, click on the "Close Report" button, make any changes to the data you have entered, and re-create the report.

After you have printed your analysis report, you are ready for Step 2 which is the equipment selection assistance section of the program. Click on the "Goto Step 2" button. The screen will be updated to show you the three model lines and a brief description of each. Select the model that best meets you needs.

Each model line will show a split screen with the available burners shown at the top with some helpful information, i.e. size of the burner, tube configuration, etc. Click on the blue ball to the left of the model you wish to use. The specific information for that model will be displayed in the bottom half of your window.

Fill in the blanks pertaining to the type of burner you wish, natural gas or propane, enter the tube configuration and length of tube you require, and enter in a quantity of optional equipment you wish or require. Now click on the "Create Burner Report" button. A new window will appear with the system that you have selected. Print the report by clicking on the Print button or selecting the File then Print menu items. If for some reason nothing has printed, simply close the window, and click on the "Create Burner Report" button, and try again.

Go back to Heat Loss Calculation.