Insulation thickness calculation 3

[vij36]

I have a requirement to insulate the ceiling of a server room as the floor above is getting cold because of the server room cooling.

Planning to use xlpe (PE cross linked material) as the insulation.

How to know how much insulation thickness required ?

I got this formula for heat transfer Q = K * A * (delta T) / X

Q - heat load (watts)
K - thermal conductivity
A - area across which heat flows
delta T - temperature difference
X - insulation thickness

I want to calculate X. but got stuck on calculating Q. Cld please give some inputs on this calculation of heat load.

Server room is maintained at 20 degree Celsius. And I measured above floor temperature and that is at 22.7 degree Celsius which has to be at 29 degree as per the user.

 

[IRstuff]

29C? That seems a bit warm -- 84F What's causing the room to be so warm?

In any case, you have a 2.7 degree rise in the existing floor, so that should get you the heat flow, which you can then use to get the 7 degree rise

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[vij36]

Sorry, I may not have conveyed the scene properly.

Floor above server room means the floor of the room above server room (not the entire room, only floor of the room) which need to be maintained at 29 C as per the use requirement. Currently because of the below ground floor server room, the above floor temperature is decreased to around 23 C which the user is feeling cold when they walk bare foot. Normal floor temperature is 29 C at least has to be maintained. So we need to insulate the below server room ceiling so that above floor heat transfer will not happen and thus preventing the floor becoming cold.

I have attached a small ppt for your reference. I would like to know how much insulation thickness is required so that heat transfer will not happen from first floor user room to below ground floor server room. So that first floor temperature will be at 29 C.

Please let me know any clarification required.

 

[LittleInch]

You're over thinking this.

Too many unknowns and with something as vague as what the user "feels" in bare feet you're never going to do this by calculation.

Just use some pu foam backed plasterboard like this

https://www.roofingoutlet.co.uk/pro...ium=cpc&utm_source=google&utm_campaign=Google

Shopping&gclid=EAIaIQobChMIgomx4cPv4AIVq5XtCh1xBg85EAQYASABEgKFLfD_BwE

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[IRstuff]

OK, what I described still holds true. You have an existing 2.7 deg delta across the existing flooring and its equivalent insulation. That gives you the amount of heat flow through the existing floor. With that heat flow and the new requirement of 9 degree delta tells you how much better your insulation needs to be.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

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[vij36]

Thanks both of you, I will give this data to vendors for a proposal for achieving 9 degree delta.

 

[racookpe1978]

IF the floor temperature upstairs is to become a steady-state 29 degrees C, then the average air temperature at 1.5 meters will be 34-35 degrees, and the upper room ceiling level temperature (at 2.1- 2.5 meters) will be an unbearable 35-40 degrees. High air flow (to circulate enough air to maintain 29 floor temperature) is unlikely to be comfortable either at any combination of air temperature and humidity.

Tell your bare-foot walker to lay a carpet down under his chair, then sit in it.

 

[vij36]

But even then we would like to prevent the heat transfer from first floor to ground floor server room.

 

[georgeverghese]

Draw up a sketch of all the resistances in series for current Case 1. Compute Q1. Then add on the additional resistance for the new insulation layer and compute Q2, surface temp on upper floor by trial and error.

Use an insulation material for the server room which has a decent resistance to fire, like mineral wool. Same for any insulation cladding. Definitely keep away from polyurethane / polyisocynurate foams and the like, even if they have better insulation properties. Get the written approval for insulation material from your safety engineers / local council fire protection authorities also.

 

[chicopee]

In heat transfer textbooks, there is a section titled "Critical Thickness of Insulation."