## Heat Loss Calculator Surface Area Error

### Heat Loss Calculator Surface Area Error

The heat loss calculator appears to have a bug in calculating surface area of a cycliner when adding layers to the cylinder. Refer to the example for Hot water tank. The outside surface is off by 2%. If you change the thickness or make the diamter larger the error increasese rapidly.

Any comments? or am I doing something wrong?
PMS
pmstory

Posts: 1
Joined: Sat Nov 03, 2007 5:51 am
Location: US

### Re: Heat Loss Calculator Surface Area Error

In the Hot water tank example, the outside area is:

outside diameter outside height
Asides= PI*(3+2*0.005+2*0.05)*(4+0.005+0.05+0.005+0.05)=40.156m2

outside diameter
Atop=PI*(3+0.005*2+0.05*2)^2/4=7.596m2

outside diameter
Abottom=PI*(3+0.005*2+0.05*2)^2/4=7.596m2

The thickness of the walls, roof and bottom are added on to the inner dimensions according to the simple picture shown by pressing the "Draw" button.

Best Regards,
Peter
Peter B

Posts: 2
Joined: Thu Aug 07, 2008 4:46 pm