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# Quiz10questions - Window coatings that only let through...

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Window coatings that only let through certain types of light are called Correct B ) spectrally selective coatings Spectrally selective coatings only let through certain types of light 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 effective U- value of the window to 0.1429. Assume heating price to be \$10/MMBTU and the cost for filling Argon is \$20. Correct D ) 0.28 years R-value of new window = 1/0.1429 = 7 Heat lost through new window per year = (10 x 2) / 7 = 2.84 MMBTUs/yr Reduction in heat lost per year = 10 - 2.84 = 7.16 MMBTUs/yr Savings in energy cost per year = 7.16 x 10 = \$71.6 Payback period = 20 / 71.6 = 0.28 yrs _______ gas is used in gas filled windows to improve thermal performance Correct A ) Krypton Inert gases like Argon and Krypton are used in gas filled windows to improve thermal performance The __________ the U-Factor the less heat the window allows to pass through. Correct A ) Smaller The smaller the U-Factor the less heat the window allows to pass through ______________ measures how well a window blocks heat from the sunlight Correct

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A ) Solar Heat Gain Coefficient (SHGC) SHGC measures how well a window blocks heat from the sunlight ----------------------------------- Heat loss and gain occur by infiltration through cracks in the window assembly by _________ Correct A ) Convection Air leaks into or outside through cracks. Thus, heat is transfered by convection. We have a window with SHGC=0.29 and VT=0.44. What is the LSG? (3 Points) Correct D ) 1.52 LSG = 0.44 / 0.29 = 1.517 ------------------------------------- Spacer materials used in a window reduce Correct A ) conduction losses Spaces material usually has a high R-value and is used to reduce conduction losses in a window ------------------------ Most low-e coatings __________ the amount of visible light transmitted through the glazing relative to clear glass. Correct A ) slightly reduce
Most low-e coatings sligtly reduces the amount of visible light transmitted through the glazing relative to clear glass We have a window with SHGC=0.61 and VT=0.67. What is the LSG? (3 Points) Correct A ) 1.1 LSG = 0.67 / 0.61 = 1.098 --------------------------- The heat loss through a window (U-value = 0.33) is 10 MMBTU/year. Calculate the payback period (in years) if Argon is filled in the window to increase the effective U- value of the window to 0.1250. Assume heating price to be \$10/MMBTU and the cost for filling Argon is \$20. Correct D ) 0.32 years R-value of new window = 1/0.125 = 8 Heat lost through new window per year = (10 x 3) / 8 = 3.75 MMBTUs/yr Reduction in heat lost per year = 10 - 3.75 = 6.25 MMBTUs/yr Savings in energy cost per year = 6.25 x 10 = \$62.5 Payback period = 20 / 62.5 = 0.32 yrs --------------------------- 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 effective U-

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Quiz10questions - Window coatings that only let through...

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