Heat loss through a wall

  • Thread starter tweety1234
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  • #1
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Homework Statement



Calculate wall loss rate in BTUs per hour. For a 10 ft by 10 ft room with an 8 ft ceiling, with all surfaces insulated to R19 as recommended by the U.S. Department of Energy, with inside temperature 68°F and outside temperature 28°F:

heat loss = [tex] \frac{Q}{t} = \frac{(Area) \times (T1-T2)}{R} [/tex]

I dont get the working out,

can someone please explain why the area is 320ft^{2}?

[tex] \frac{Q}{t} = \frac{(320 ft^{2}) \times (68-28)}{19} [/tex]


surely its just 10 x 8 = 80 ft?
 

Answers and Replies

  • #2
gneill
Mentor
20,925
2,866

Homework Statement



Calculate wall loss rate in BTUs per hour. For a 10 ft by 10 ft room with an 8 ft ceiling, with all surfaces insulated to R19 as recommended by the U.S. Department of Energy, with inside temperature 68°F and outside temperature 28°F:

heat loss = [tex] \frac{Q}{t} = \frac{(Area) \times (T1-T2)}{R} [/tex]

I dont get the working out,

can someone please explain why the area is 320ft^{2}?

[tex] \frac{Q}{t} = \frac{(320 ft^{2}) \times (68-28)}{19} [/tex]


surely its just 10 x 8 = 80 ft?
How many walls are there in a square room?
 
  • #3
112
0
How many walls are there in a square room?

4? But how does that make 320?
 
  • #4
112
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Dont worry, I got it,

thanks for your help.
 

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