Modelling Ceiling Plenum

[Richardo1505]

Hi all,

does anyone have experience of modelling a dropped acoustic ceiling under exposed concrete soffit.

I'm looking to show the thermal performance of a space with exposed concrete to soffit for thermal mass but with an acoustic ceiling section with holes to maintain the exposed thermal mass.

if I model the ceiling sections as standard prisms these have internal volumes, I'm thinking it might be possible to model the ceiling sections as linked components that are finalized into the space?

any help would be greatly appreciated. Thanks

[Terence]

If you have exposed concrete and no ceiling void, then drawing the soffit as a zone would not be the best option.

The best option would be to reduce the "internal surface resistance" of the inner surface of the slab construction in Apache Constructions database.

By reducing the surface resistance from the default value you are effectively allowing for more effective heat transfer and greater thermal mass in the space.

This allows you to keep the model geometry very simple, which will keep the simulation time down.

Say you have a 10mx10m concrete slab bewteen floors, this equals 100m2. But in your case you have a coffered slab, so the actual surface might be 150m2 including the additional area.

100/150 = 0.67

So you could multiply the default surface resistance of the inner surface by 0.67 to give a new lower resistance figure. This is effectively increasing the surface area and subsequently the heat transfer effects by 33%.

This 33% value would be varied depending on how much default surface area to effective surface area you have.

[marcocooper]

Do you really think that reducing the "internal surface resistance will really help as the simulation will decrease.