






























Quantity  SI Units  English Units 
E  J  BTU 
¶E/¶t  W  BTU/hr 
H  J/m^{3}  BTU/ft^{3} 
¶H/¶t  W/m^{3}  BTU/hr ft^{3} 
q  W/m^{2}  BTU/hr ft^{2} 
k  W/m K  BTU/hr ft ^{o}F 
r  kg/m^{3}  lb/ft^{3} 
C_{p}  J/kg K  BTU/lb ^{o}F 
a  m^{2}/s  ft^{2}/hr 
h  W/m^{2} K  BTU/hr ft^{2o} F 
s  5.729 ×10^{8} W/m^{2} K^{4}  0.173 ×10^{8} BTU/hr ft^{2o} R^{4} 
English Units  SI Units 
1 BTU  1,055 J 
1 BTU/hr  0.29307 W 
1 BTU/ft^{3}  37,260 J/m^{3} 
1 BTU/hr ft^{3}  10.3497 W/m^{3} 
1 BTU/hr ft^{2}  3.154591 W/m^{2} 
1 BTU/hr ft ^{o}F  1.7307 W/m K 
1 lb/ft^{3}  16.02 kg/m^{3} 
1 BTU/lb ^{o}F  4,186.8 J/kg K 
1 ft^{2}/hr  2.5807 ×10^{5} m^{2}/s 
1 BTU/hr ft^{2o}F  5.6782 W/m^{2} K 