Kroll GK20 23kW (78,476Btu's) Oil fired space heater

If you have it in cfm then multiply your cfm value by 1.7 to get m3/hr

F8 bag filters pressure drop - typical clean clean to dirty, 160 - 250 Pascals

F9 compact filters pressure drop - typical clean to dirty, 160 - 350 Pascals

H10 HEPA filter pressure drop - typical clean to dirty, 250 - 600 Pascals

9.8 Pascals = 1 mm wg, & 249 Pascals = 1 inch wg

For compact type carbons pressure drop between 100 - 150 Pa

Bonded carbon panels typically 150 - 170 Pa

Loose granular carbon panels typically 130 Pa

8760 hours in a year

If operating for 5 days a week, excluding public holidays, for 12 hrs/day = 3000 hrs

Huge variance in what different companies pay.

heck your last bill to be sure, otherwise put in 10p

Would typically be around 60%, so if you don’t have specific information use 0.6

Larger motors should be around 90%, so if you don’t have specific information use 0.9