Help with ducted system required

[andyg]

Hi everyone,am new to RE,and am hoping someone can help me out.
My background is almost exclusively fridge,with a few splits thrown in,
I have a customer thast really wants a ducted air con system for their restaurant.
Have detailed job below,please help!
Restaurant has a flat roof with no void at all,there is the ceiling,the joist,then the roof.
Restaurant is 13m x 13m x2.5m,with 3 x 2m long east facing windows,and 3 x 2m long south facing windows, both 1.5m high.
seating for 100 people.
They are having a flat plasterboard finish to the new ceiling with a precise lighting plan,to accomodate LED lights.
There is limited space in non public areas to install the ducted unit(s)
They plan to reopen in 4-6weeks.
The shopfitters have got the raving hump,because they assumed that they were getting the job,so they are going to be less than helpfull.

Please tell me that its a nightmare job and that none of you would go near it!
cheers all,
Andy G.

[24057]

You're quite right, this would be a bit of a nightmare job. This is because it's essentially impossible to install void mounted ducted units without any void at all. The only option would be to suspend the units below the ceiling, meaning their visible to all, and chances are, the ducting and pipe run etc would clash with the lighting plan. Also, unless it was a very neat job and all ducting was powder coated white etc, it would look very unsightly in my opinion. Being a total height of 2.5, would also mean the units would impose upon the space of the room and would look ridiculous as the ducting would have a minimum diameter of 200. The only options it seems would be to add wall mounts around the perimeter or slimline cassettes maybe. However, neither of these are idea as they both create drafts and would annoy anyone eating beneath them or directly in line with their air flow. I should also imagine that due to the seating capacity of the restaurant, that building regs would specify there should be 'x' amount of fresh air supply too, meaning further ducting etc.

Hope this helps

[Tesla]

Just a thought out of the square but not conventional - you could try a chilled beam low profile system with a few rustic retro oscillating fans. Still need to provide around 1000 liters per second fresh air like 24057 posted. Which ever way you go it will be costly and full of head aches. Like you said give it a miss. It's a small job and profit to reinvent the wheel especially when you know the motor and not the wheel.

[MikeHolm]

Over here, most of the stuff is ducted, and I have a hell of a time getting people to go back to rads. Ducted is also cheaper and more known, since WW2. Dirtier, less comfortable and more noisy. Just saying.....

[martinw58]

can you install the units out side on the roof and duct through the roof keeping all the ductwork outside

[install monkey]

prob best option- is unico ducting- small ducts with nozzles- as if ur chomping a 200mm hole through a roof ur gonna hit joists,beams,fire walls, is there an external wall u could fit underceiling units , if not sack it off, should have got duct in place before the ceiling went in

[paulg88]

If I had space to mount in the non public area, I'd think about ducting solid to the wall of the public area, transition piece, and then an air sock. I used them a few times and think they're ok looking on the eye when I'd no other choice.
Have used this one a few times... http://www.ke-fibertec.co.uk/air_socks.html

[S_Line]

What we hve done is Drop the Ceiling paremiter on two side or all round, about 1.5 meters in fromt he edge of the room and drop the ceiling about 200mm then put MHI Slim duct units with return air grille under (in the dropped ceiling) the supply air out the side (200mm) very little drafts, infact none at all.
ITs the best way to do this kind of situation.
Refrigeration pipes can go staight up throught he flat roof and into a multi system

[nevinjohn]

Just a thought out of the square but not conventional - you could try a chilled beam low profile system with a few rustic retro oscillating fans. Still need to provide around 1000 liters per second fresh air like 24057 posted. Which ever way you go it will be costly and full of head aches. Like you said give it a miss. It's a small job and profit to reinvent the wheel especially when you know the motor and not the wheel.

Is it really a good idea having chilled beams in a restaurent, where theres lot of latent load?

[nevinjohn]

Try packaged units installed on the roof.