Vaporization Rates for Propane Tanks

Vaporization Rates for Propane Tanks Maximum Intermittent Withdrawal Rate (BTU/HR) Without Tank Frosting* if Lowest Outdoor Temperature (Average For 24 hours)
Temperature 150 Gal. 250 Gal. 500 Gal. 1000 Gal.
40° F 214,900 288,100 478,800 852,800
30° F 187,900 251,800 418,600 745,600
20° F 161,800 216,800 360,400 641,900
10° F 148,000 198,400 329,700 587,200
0° F 134,700 180,600 300,100 534,500
-10° F 134,200 177,400 294,800 525,400
-20° F 108,800 145,800 242,300 431,600
-30° F 107,100 143,500 238,600 425,000

* Tank frosting acts as an insulator, reducing the vaporization rate.

A number of assumptions were made in calculating the BTU figures listed in the table above:
  1. The tank is one-half full.
  2. Relative humidity is 70%.
  3. The tank is under intermittent loading.
Although none of these conditions may apply, the Table above can serve as a rule-of-thumb in estimating what a particular tank size will provide under various temperatures. Under continuous loading the withdrawal rates in the Table should be multiplied by 0.25.