HAP- ROOF ASSEMBLY

[Miraak997]

I have about 1050 m2 of a space, the roof is built up of metal sheets - airspace and acoustic tiles, I just want to know if the assembly of layer I did is correct or not, the area is located in Africa Nigeria outdoor condition is 33DB/29WB I'm getting a load of about 112 kWs.
Could someone please check for me If I'm made a mistake with the layers ?

 

[moideen]

No need to waste time. The architect will provide the roof's U-value. For an HVAC designer, the roof assembly type isn't important; just use the architect's U-value and adjust the roof section to match it. This is my view.

 

[Miraak997]

No need to waste time. The architect will provide the roof's U-value. For an HVAC designer, the roof assembly type isn't important; just use the architect's U-value and adjust the roof section to match it. This is my view.

Funny thing is I can't even get that, this warehouse have been on for years, they can't even reach them anymore.

Actually I really disagree with you regarding that, you could face lots of scenarios with no enough data or provider, in this case you need to figure it out all by yourself.

 

[HVAC-Novice]

No need to waste time. The architect will provide the roof's U-value. For an HVAC designer, the roof assembly type isn't important; just use the architect's U-value and adjust the roof section to match it. This is my view.

I only want to add, make sure the architect gives you the correct U-values accounting for thermal bridges etc. Cross-reference with ASHRAE 90.1 Appendix A to be safe.

I have seen people using an R21 value for a 6" metal stud wall because the 6" insulation add up to R19 plus the sheathing... they had ignored the metal studs, which drops R-value to under 10.


If this is an existing building, review plans or insulation details and field-survey. Assume conservative values. Make clear to the owner, that the less they can provide, the more expensive the new system will be due to possible over-sizing.

 

[moideen]

Before installing the walls and roof in HAP, the building designer or architect must provide the wall and roof sections. it may be submitted to the relevantlocal authority for approval before work can begin. This applies to new buildings; some models are attached. For existing buildings or retrofits, the actual wall and roof assembly details must be obtained from the site, which can be challenging