quiz lesson 10

The window panes does have an eect on

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Unformatted text preview: wnings can significantly reduce the energy required for air condi*oning Typically, windows have an R- value ________ the wall. Correct A ) Lower than Typically, windows have an R- value lower than the wall Heat always flows from ______ temperature to _______ temperature Correct A ) high, low Heat naturally flows from high temperatue to low temperature The R- value for a window is the reciprocal of the Correct A ) U- value or U- factor R- value is a measure of how well it resists conduc*on of heat through the material. R- value = 1 / U- value = 1/ U- factor The higher the light- to- solar gain ra*o, the _______ the room is without adding excessive amounts of heat Correct A ) brighter Light- to- Solar Gain = Visual TransmiFance / Solar Heat Gain Coefficient The higher the light- to- solar gain ra*o, the brighter the room is without adding excessive amounts of heat Inert gas fills between two window panes reduces Correct A ) convec*ve heat loss between the panes Inert gas fills between two window panes reduces convec*ve heat loss between the panes The heat loss through a window (U- value = 0.5) is 10 MMBTU/year. Calculate the payback period (in years) if Argon is filled in the window to increase the effec*ve U- value of the window to 0.100. Assume hea*ng price to be $10/MMBTU and the cost for filling Argon is $20. Correct C ) 0.25 years R- value of new window = 1/0.100 = 10 Heat lost through new window per year = (10 x 2) / 10 = 2 MMBTUs/yr Reduc*on in heat lost per year = 10 - 2 = 8 M MBTUs/yr Savings in energy cost per year = 8 x 10 = $80 Payback period = 20 / 80 = 0.25 yrs The __________ the U- Factor the less heat the window allows to pass through. Correct A ) Smaller U- factor is a reciprocal of R- factor. The smaller the U- factor the less heat is allowed to pass through ______________ measures how well a window blocks heat from the sunlight Correct A ) Solar Heat Gain Coefficient (SHGC) SHGC measures how well a window blocks heat from the sunlight The ___________ a window's solar heat gain coefficient, the less solar heat it transmits. Correct A ) lower Solar Heat Gain Coefficient is expressed as a number between 0 and 1. The lower a window's SHGC, the less solar...
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