Answer :
After calculating the heat generated by the computers and occupancy and adding the existing cooling requirement, we find that 5 air conditioners of 6000 Btu/h are needed to cool the new computer room. Hence, option d) is correct.
To determine how many 6000 Btu/h air conditioners are needed to cool the new computer room, we need to calculate the total heat load generated by the computers, printers, and additional occupancy, and then divide that by the cooling capacity of each air conditioner available.
Firstly, for the computers and printers:
Power consumed = Total rated power times usage factor = 8.5 kW times 0.5 = 4.25 kW.
Converting this power to Btu/h using 1 W = 3.412 Btu/h:
Heat generated by computers = 4.25 kW times 1000 W/kW times 3.412 Btu/h/W = 14491 Btu/h.
Next, for the occupancy of eight people:
Heat generated = Number of people times Heat per person = 8 times 125 W/person = 1000 W.
Converting this to Btu/h:
Heat generated by people = 1000 W times 3.412 Btu/h/W = 3412 Btu/h.
Adding the existing cooling requirement (14,000 Btu/h), the computers and printers (14491 Btu/h), and the additional occupancy (3412 Btu/h), we get the total new cooling requirement:
Total cooling required = 14,000 Btu/h + 14491 Btu/h + 3412 Btu/h = 29903 Btu/h.
To find out how many 6000 Btu/h air conditioners are needed, we divide the total cooling requirement by the capacity of one air conditioner:
Number of air conditioners = Total cooling required / Capacity of each air conditioner = 29903 Btu/h / 6000 Btu/h ≈ 5.
Therefore, 5 air conditioners of 6000 Btu/h are needed to adequately cool the new computer room.
Hence, option d) is correct.