Air conditioning through coloumn diffusser 4

[mouli11]

Hi i am an electrical engineer!! .The area to be airconditioned is large Airport Terminal building with ground and first floor .The celilig height from floor is 4.5 MTR for both ground and first floorarea.I have normally seen that we use either ceiling area (Covered with false ceiling)or Flooring (Covered with false flooring) for running the Air conditiong ducts from heat exchanger to the the area to be conditioned and the return air is collected through the false ceiling/Flooring itself. I was given to understand that the Air conditioning can be provided along with the coloumn area through high velocity discharge nozzles to avoid the ducting in the ceiling area .Can anyone suggest how this arrangements is possible . Is the basement necessarry for airconditioning through Colomn ?.or can any one suggest any other arrangement to provide Aitconditioning system without running ducts through celieng /flooring area. Fan coil units and package type units may be not possible sine the area is very big.

 

[SAK9]

Chandramouli?If yes, let me know your email!

 

[mouli11]

HI sak 9
Pl note my add
mouli11@vsnl.net

 

[ChrisConley]

Has displacement ventilation been considered? Ceilings are quite high, large space, could be an effective way to supply cooling.

With displacement ventilation a duct is run low to the ground, around the perimeter of the space to be conditioned, and fitted with a _low_ velocity diffusers. The air that is released is set at 5-8 deg F cooler than room air. The cool, low velocity air (<40fpm) then flows along the floor until it encounters a heat source (person, equipment). The rising air from the heat source draws the cool air over the heat source. Hot air is then collected/stored in the high ceiling space. Stratification in used to reduce total cooling requirement. Return air grilles can be located anywhere high.

ASHRAE has a good design guide on displacement ventilation systems. Other key points are improved ventilation effectiveness (~1.2) reducing required OA by 20% and no drafts.

 

[Accystan]

You may also want to check out the Trox website at:

http://www.troxuk.co.uk/grilles.html

They have good information on displacement diffusers.

Cheers.

 

[nans]

Read your question and it is an interesting challenge

I have done one project using Low Velocity Displacement Ventilation Diffusers (LVDV) which was fixed to the columns...supply through the columns.

http://www.haltongroup.com/catalog/index.htm

this site gives lot of solutions for displacement Ventilation.

 

[Whoops]

"Has displacement ventilation been considered?"

Displacement ventilation was installed at Stansted airport, built about 10 years ago. I believe it was very sucesful. Try a search on Google. I don't think displacement ventilation could deal with the large cooling loads required in less temperate climates, but I don't know.

 

[jherbert]

hi,

You have described the Hong
Kong International Airport
system.

Can it be done ? yes

cheers,

 

[Stormxtc]

Hi,

Krantz are the experts on displacement ventilation. Airports are their specialty.

You should look them up Google/Yahoo.

StormXTC

 

[mouli11]

Thanks every body , i shall have a trip to Hong Kong Airport to see how does it works !!!!.Courtesy jherbert

 

[jherbert]

hi,
A trip would be a bit of a waste of time, there is
really nothing to see, except id you want to see
lots of diffusers or like airports. The system is
as you described, basement plant with column risers in the terminal. Shops, offices and stalls use FCU's. Inadequate exhaust and No a/c in toilet areas was BIG mistake.

columns housing supply and return are finished with steel enclosures. Risers also used to house hose reel's, telephone and general power.

cheers,