1. A home uses twenty 60W, 2% efficient incandescent bulbs, which are all 'on' anaverage of...

Transcribed Image Text:

1. A home uses twenty 60W, 2% efficient incandescent bulbs, which are all 'on' anaverage of 4 hours daily. a) find the annual energy use b) what wattage would be required for a 15% efficient LED light to produce the same illumination as the 60 W? 2. With 4 showers a day, each 7 minutes long at 38C: a) what is the annual energy use for a 60% efficient gas water heater, assuming a water input temperature of 5 and 10 L/minute usage. 3. A 10m by 10m by 4m cabin has 10cm thick foam walls (k=0.04WmK-). a) If we wish to keep the interior at 10C during the winter when the outside temperature averages 5C, what average power rating is required for an electric baseboard heater? Assume the cabin is on posts so heat is lost through the floor as well. 1. A home uses twenty 60W, 2% efficient incandescent bulbs, which are all 'on' anaverage of 4 hours daily. a) find the annual energy use b) what wattage would be required for a 15% efficient LED light to produce the same illumination as the 60 W? 2. With 4 showers a day, each 7 minutes long at 38C: a) what is the annual energy use for a 60% efficient gas water heater, assuming a water input temperature of 5 and 10 L/minute usage. 3. A 10m by 10m by 4m cabin has 10cm thick foam walls (k=0.04WmK-). a) If we wish to keep the interior at 10C during the winter when the outside temperature averages 5C, what average power rating is required for an electric baseboard heater? Assume the cabin is on posts so heat is lost through the floor as well.