quiz lesson 9

# Air is heated maximum amount of water

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Unformatted text preview: years We know that, 1 ton of air condi3oning = 12000 BTU/hr Old air condi3oner Power consump3on = 3 x 12000 / 9 =4000 wa\s Energy cost = 4000 x 2000 / 1000 x 9.2 / 100 = \$736 New air condi3oner Power consump3on = 3 x 12000 / 13 = 2769.23 wa\s Energy cost = 2769.23 x 2000 / 1000 x 9.2 / 100 = \$509.54 Savings in energy cost = 1371.42 - 738.46 = \$632.96 Pay Back period = 500 / 226.46 = 0.715 yrs Room air condi3oners have a higher eﬃciency than central air condi3oners. Correct B ) FALSE Central air condi3oners have a higher eﬃciency than roof air condi3oners. Roof overhangs reduce cooling costs. Correct A ) T RUE Roof overhangs reduce cooling costs In the compressor of an air condi3oner, pressure _____. Correct A ) Increases In the compressor of an air condi3oner, pressure increases Air at 90 F contains 0.03 lb of moisture per lb of dry air. The satura3on level at that temperature is 0.04 lb/lb of dry air. What is the rela3ve humidity? Correct C ) 75 percent Rela3ve humidity = 0.03 / 0.04 x 100 = 75% Which term is used to deﬁne the energy eﬃciency of a room air condi5oner? Correct B ) E ER EER is used to deﬁne the energy eﬃciency of a room air condi5oner Which term is used to deﬁne the energy eﬃciency of a room air condi3oner? Correct B ) E ER EER is used to deﬁne the energy eﬃciency of a room air condi3oner Oversized air condi3oners (and heat pumps) do not run long enough to dehumidify the air. Correct A ) T RUE Oversized air condi3oners (and heat pumps) do not run long enough to dehumidify the air. Size of air condi3oner doesn't depend on how much shade is on your home's windows, walls and roofs. Correct A ) FALSE Size of air condi3oner depends on how much shade is on your home's windows, walls and roofs Your old high school pal Mike Errington wants to upgrade an old 1976 vintage room air condi3oner that is believed to operate at an E ER of 6. He is considering a room air condi3oner with an E ER of 12. He wants to know by what frac3on the electricity consump3on would reduce? Can you help ﬁnd it? Correct A ) 0.5 1- 6/12=0.5 What happens to the temperature of refrigerant in the expansion valve of an air condi3oner? Correct A...
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## This note was uploaded on 09/24/2013 for the course EGEE 102 taught by Professor Pisupati,sarmave during the Spring '07 term at Penn State.

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