Heat Loss in insulated Pipework

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SUMMARY

The forum discussion focuses on calculating heat loss in insulated copper pipework, specifically a pipe with a 15mm insulation thickness, an outside radius of 17.2mm, and an inside radius of 14.8mm. The thermal conductivity of the insulation is specified as 0.025 W/m·K. The calculated heat loss is reported as 11.27 W/m, which the user, Tom, questions as being higher than expected. The discussion highlights the importance of correctly applying the heat loss equation for insulated cylinders or pipes, as well as ensuring accurate input values in the calculations.

PREREQUISITES
  • Understanding of thermal conductivity and its units (W/m·K)
  • Familiarity with the heat loss equation for insulated cylinders
  • Basic knowledge of Excel for performing calculations
  • Concept of pipe insulation and its impact on thermal performance
NEXT STEPS
  • Review the heat loss equation for insulated pipes in engineering texts
  • Learn how to use Excel for thermal calculations, including functions for complex equations
  • Investigate different insulation materials and their thermal conductivities
  • Explore methods for verifying heat loss calculations through practical experiments
USEFUL FOR

Engineers, HVAC professionals, and anyone involved in thermal management or insulation design for piping systems will benefit from this discussion.

Howlin
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TL;DR
how to calculate the w/m heat loss in pipework with xmm of insulation
Hi all,

I have a copper pipe which has 15mm of insulation on it. The outside radius of the pipe is 17.2mm and the inside radius is 14.8mm. The insulation will have a conductivity of 0.025.

I found an question which is meant to show an equation for the heat loss in an Insulated Cylinder or Pipe. I have attached an excel document which has this equation in it and the inputs.

When I calculate the heat loss in w/m, I get a figure if 11.27.

I am wondering is the correct, as it doesn't appear to be, I would have thought it to be lower, somewhere in the region of 8 or 9 w/m.

Can anyone tell me if it is right or where I might be going wrong?
 

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Engineering news on Phys.org
It all depends on these two numbers that you assumed.

1580398150894.png
 
I notice the spread sheet has the Insulation radius smaller Pipe radius.

Are you really trying to insulate the inside of the pipe? o_O

Cheers,
Tom
 

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