* Ratings at 140°F and lower temperatures determined by multiplying 150°F rating by the applicable reduction factor
All the above ratings are based on active length, which is 3" less than total length, and includes a 15% addition for heating effect.
Ratings: Heating capacities are listed in Table 1 for two flow rates: 1 GPM and 4 GPM. The use of ratings at 4 GPM is limited to installations where the water flow rate through the baseboard unit is equal to or greater than 4 GPM. Where the water flow rate through the baseboard is not known, the ratings at the standard flow rate of 1 GPM must be used.
Table 2  Factors for ratings at flow other than standard and pressure drop values 
Rate of Flow GPM

1.0 
1.5 
2.0 
2.5 
3.0 
3.5 
4.0 
4.5 
5.0 
6.0 
Factor

1.000 
1.016 
1.028 
1.038 
1.045 
1.051 
1.057 
1.062 
1.067 
1.074 
Pressure Drop 3/4" Tube
Mill inches per ft.

47 
96 
157 
230 
320 
420 
525 
650 
775 
1060 
Note: If the calculated water flow rate through a baseboard unit in a completely designed hot water heating system is greater than the standard flow rate (1 GPM), the rating of that unit may be increased by multiplying the standard rating at 1 GPM by the factor shown for the calculated flow rate.