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## Homework Statement

I have a manufacturing plant, and I know the material/thickness of every wall and the roof. I want to estimate the plant as an empty box, where I know the surface area of each material surrounding the box (ex. 4000 sq ft concrete, 1000 sq ft of windows, 1000 sq ft of xyz roofing, etc.). I'm trying to determine how long this plant would take to go from 70F to 32F internally if the outside air is 0F and the heating to the building were discontinued.

I'm going to assume that no convection is taking place and only conduction and radiation are taking place. Would a building radiate a significant amout of heat, or should I only concern myself with conduction across the walls/roof?

## Homework Equations

Unsure, but heat transfer equations.

Possibly:

ΔT=RQ

ΔT=Q(rate)(R)/(A)

## The Attempt at a Solution

Not really sure to start with this. I'm planning on determining the rate of heat that is going to escape the plant, then looking at the specific heat of the internal air and determining how long it would take to drop the inside air to 32F. I'm looking for a lot of insight though. I'm not too sure of what factors I should be considering and what heat transfer principles/equations would apply.

For reference, I'm an upcoming senior Mechanical Engineer in undergraduate. I've taken thermo, however have not yet taken heat transfer.

Thanks for any help.