Question

The lighting needs of a classroom are met by 30 fluorescent lamps, each consuming 80 W of electricity (Fig. 2-52). The lights in the classroom are kept on for 12 hours a day and 250 days a year. For a unit electricity cost of 11 cents per kWh, determine annual energy cost of lighting for this class- room. Also, discuss the effect of lighting on the heating and air-conditioning requirements of the room.

Answer 1

Soluhon Amount al watage consumed per year 30×80 wメ12×360oxマ50 59Rx10 K 6Y 3 3.6×10 JoY 3.6×10 kて Mow 8592x 1D kJ 7 Kwh 3. 593 x10 3- 6 X103 れニ7200 kuoり Peice - koh 11 cemt 7300 X)1 7ス00 koわ →y 79R00 cent Slightning 793 doller Cost Annual unuub a For 30 lomp emurgy Consumptiony.. 80X30 3400 J seL 24DOY60s こ144K5 ay Repigerahion 1ks on ag Lefigenahion144 s 1 Ton min A t min A 6.685 Say that ighting af 30 bes lamp add O.685t0ns We can ay Refiger ahon doud on the Toom. which shald be air conditioning ystem handled by YOom