Charts for BTU's, Piping, and Water Volume
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Copper Related Information
- BTU Carried by Copper Pipe
- Total Number of Convectors per Pipe Size
- Maximum amount of Baseboard per Loop
- TEF of Copper Fittings
Cast Iron and Black Pipe Related Information
- Maximum Amount of Cast Iron Baseboard per loop
- BTU/Water temperature/Output Cast Iron Radiators
- TEF Black Fittings
Water Volume of Radiation and Piping
Industry Standard BTU Capacity of Copper Pipe
| Pipe Size | Total BTU's |
| 1/2" | 15,000 |
| 3/4" | 40,000 |
| 1' | 75,000 |
| 1 1/4" | 160,000 |
Total Number of Convectors per Pipe Size
Sample convectors are 6 1/4" x 24" x 32"
Output 5000 Btu's each
| Pipe Size | |
| 3/4" | 8 |
| 1" | 16 |
| 1 1/4" | 28 |
Disclaimer: The information found on this website is for informational purposes only. All preventive maintenance, service, installations should be reviewed on a per-job situation. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc and its personnel accept no responsibility for improper information, application, damage to property or bodily injury for applied information found on this website.
Maximum amount of Baseboard per Loop
Rating per ft
| Pipe Size | Rating @ 180º | |
| 3/4" | 590 | 67 3/4' |
| 1" | 800 | 100' |
| 1 1/4" | 850 | 164 3/4' |
Disclaimer: The information found on this website is for informational purposes only. All preventive maintenance, service, installations should be reviewed on a per-job situation. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc and its personnel accept no responsibility for improper information, application, damage to property or bodily injury for applied information found on this website.
Maximum Amount of Cast Iron Baseboard per loop
Rated at 620 Btu's ft @180 degrees and 4 gpm
| Pipe Size | |
| 3/4" | 64' |
| 1" | |
| 1 1/4" | 225' |
Disclaimer: The information found on this website is for informational purposes only. All preventive maintenance, service, installations should be reviewed on a per-job situation. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc or its personnel accept no responsibility for improper information, application, damage to property or bodily injury for applied information found on this website.
Directions: Measure all cast iron radiators, see sizing a steam boiler for directions, and determine sq ft radiation. Have Comfort-Calc do your Manual-J heat loss calculation. Divide the heat loss by the sq ft of radiation. This gives you how many BTU's per sq ft of radiation is required to meet the heat loss.
Enter the chart in the bottom row (BTU) and find a number close to your needs. Go up to the water temperature required.
Example: 70,000 btu Heat loss
660 Sq ft Radiation
70,000/660 = 106 btu's per sq ft of radiation
This is close to 110 btu's per sq ft. I would use 150º water temperature
Disclaimer: The information found on this website is for informational purposes only. All preventive maintenance, service, installations should be reviewed in a per-job situation. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc or its personnel accept no responsibility for improper information, application, damage to property or bodily injury for applied information found on this website.
Disclaimer: The information found on this website is for informational purposes only. All preventive maintenance, service, installations should be reviewed on a per-job situation. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc or its personnel accept no responsibility for improper information, application, damage to property or bodily injury for applied information found on this website.
Water volume of Copper Pipe Type "L"
Disclaimer: The information found on this website is for informational purposes only. All preventive maintenance, service, installations should be reviewed on a per-job situation. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc or its personnel accept no responsibility for improper information, application, damage to property or bodily injury for applied information found on this website.
Disclaimer: The information found on this website is for informational purposes only. All preventive maintenance, service, installations should be reviewed on a per-job situation. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc or its personnel accepts no responsibility for improper information, application, damage to property or bodily injury for applied information found on this website.
Disclaimer: The information found on this website is for informational purposes only. All preventive maintenance, service, installations should be reviewed on a per-job situation. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc or its personnel accept no responsibility for improper information, application, damage to property or bodily injury for applied information found on this website.
Disclaimer: The information found on this website is for informational purposes only. All preventive maintenance, service, installations should be reviewed on a per-job situation. Any work performed on your heating system should be performed by qualified and experienced personnel only. Comfort-Calc or its personnel accept no responsibility for improper