Direct Fired Make Up Air Unit Annual Cost Of Operation  

 Hours Per Day Of Operation
CFM 4 8 12 16 20 24
1000 37 75 112 149 185 224
2000 75 149 224 299 375 448
3000 112 224 336 448 560 672
4000 149 299 448 598 745 896
5000 187 374 560 747 935 1120
6000 224 448 672 897 1120 1344
7000 261 523 784 1046 1305 1568
8000 299 598 897 1195 1495 1794
9000 336 672 1009 1345 1680 2018
10,000 374 747 1121 1494 1870 2242
20,000 747 1494 2241 2989 3735 4482
30,000 1121 2241 3362 4483 5605 6724
40,000 1494 2989 4483 5977 7470 8966
50,000 1868 3736 5604 7471 9390 11208
                                      Annual Fuel Consumption Rate (MCF/Year)
Example :  Direct Fired CFM 12,000 12 Hrs/Day 5 Days/Week
Assumptions : Efficiency : 93% Indoor Temp 70oF Outdoor Temp 28.3oF

(Mpls, MN)

 Fuel Costs 

$6.50/MCF
Results : 1121 + 224 1,345 MCF/Yr 1345 X $6.50 $8,743.00

Per Year