# Forum Home Renovation Heating & Cooling  "Closable" Ducted A/C Vents

## Roadhouse

Hi All, 
I have ducted A/C througout the house. The house is mostly a single level house with floor ducting, but the back of the house is double story and has a couple of rooms downstairs with one ceiling duct, which is a square diffuser type as per pic:   
I would like to shut this vent off completely on occasions so is one of those circular diffusers a good idea? I think they rotate and close off completely?   
Am guessing the hole in the ceiling is round so the circular diffuser should fit.  
Would think it would simply mean more air elsewhere, but would doing this cause any dramas??  
I am having zoning issues like some of the other threads I have read, but I thought this would be a quick interim solution until I get around to sorting out the zone motors.  
Cheers

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## rrobor

Have you thought about creating it as another zone  and puting a zone motor in that duct.

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## China

You can also get square units with a four way louve system that you can close off

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## Batpig

Dear Roadhouse, 
I've got the ones like China is talking about in my ceiling. They consist of a series of concentric squares, and you turn the square in the very centre around by 90deg to open or close the vent:   
Having said that, I've also seen other closeable square ones (a little different to mine...) in Bunnings Catalogues in the past for about $20 each. They caught my eye because it looked like they came with a little "fitting" that you were supposed to screw onto the end of a broom-handle, in order to be able to reach up and open and close the Vents without needing to stand on a chair or ladder. That would be very handy. 
Best Wishes,
Batpig.

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## Roadhouse

thanks guys - might actually check the current duct as perhaps I have a square one that closes by turning the centre square - ya learn something everday!!  
Will look at the zoning soon as I have a 3 zone system (apparently  :Redface: ) which work off mechs but switching the switches makes no difference to any of the vents (i.e. airflow) throughout the house. Would be doubtful 3 zone motors have crapped themselves so maybe need to be looking at something else...

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## exotiic

Roadhouse, if the mechs closing off the zones do not alter any air flow at all, there is obviously a problem with either (a) the switch mechs and or connections, (b) the zone motors or barrel dampers, or (c) the actual ductwork. In theory, when one switch is off that damper should close any air flow into that associated area. As such there should be more air coming through the other vents. That is, if when only one zone is on there is no change in air flow, the zone motors are not working or there is air leakage.

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## Roadhouse

Thanks mate - me and the old man (a sparky) had a bit of a poke around under the house and found out the following: I have one 'zone' always on, going to kitchen, bathroom and Bed 2 (used to be lounge room)Zone 2 is new lounge/dining room as well as rumpus/bar beneath itZone 3 is Bed 1 (incl walk in robe!) and Bed 3Zone 2 motor isn't working (remains fully open) so will need to be replaced.    
A couple of q's:can you replace just the motor or must you replace the complete unit i.e. motor, cam, valve/damper thingy and piece of ducting it is 'housed' in?Zone 3 motor is working fine, but when zone 3 is closed, some air still comes through into the rooms - is that normal or are the dampers in this unit getting a bit lazy (to be fair, the sticker on the motor said "warranty expires 1995")?I want to exlude the downstairs "branch" of the ducting as this space is cool in summer and ok in winter - how can I block off the branch? Happy to disconect it completely - but how do I close off the hole where I have disconnected it from the main system?If I am going to replace 1 or both motors, any suggestions on reasonable replacements? Had a quick look around and there are fancy remote control ones now etc - am probably just interested in ones that connect up to the switch mechs.  
cheers

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## exotiic

I would assume, and could be completely wrong, that being the older zones and dampers they would be easily detached by a hex head from the actual barrel. "If so, once the motor is disconnected electrically, it can be unscrewed from the blade support and replaced. Be aware though  that the motor can be either drive open/drive close or drive open/spring close, so make sure to get the same  to make things easier on yourself. If there is no hex screw to detach, then simply replace the whole barrel and damper in one. 
Zone 3 can be one of three things, which you could examine by disconnecting the duct connected to the barrel. Either there is an obstruction in the barrel which is stopping the blade from completely closing or the motor is misaligned and not opening and closing at the right intervals, so leaving gaps open, The final option is that there is no seal between the blade and barrel in the closed position  which allows air leakage. This was actually quite common in the older systems but most newer high quality damper barrels now are well supported. As such if that is the case, when replacing the above zone you may wish to change the barrel anyway to create a better seal. 
To close off the branch for downstairs there are two option which I professionally would contemplate. Firstly you can install a zone and that way if need be it can be turned on at the flick of a switch or off if not required. Secondly you can install a manual barrel damper  which fits between the ductline  and acts as a zone as above BUT is manually controlled so with a good seal inside and closing off the blade the system is basically off in that area. But when you wish to use it again its simply a matter of getting down there to open the blade again. 
If your based in Sydney I would recommend Westaflex either at Milperra or Penrith. They have high quality fittings which I use for my jobs and wont use anything less.

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## Roadhouse

thanks exotiic - your detailed response is much appreciated   :2thumbsup:  
I think you're right that the best option would be to zone the downstairs so I can always turn it back on at a flick of a switch if needed. Costs more than a 'de-branching' but more practical. Will give me the opportunity to organise the zones to my liking...  
And will have a poke around inside the ducting to see what the dampers are doing - I reckon they're the non-sealing type as they are 15 years old. If so will update with the sealing types and will be sweet.  
Will give Westaflex a buzz to see what I'm up for - thanks for the tips.  
Cheers

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## Roadhouse

Just spoke with Westaflex and the prices are very reasonable.  
FYI, a poly barrel with motor and dampers/blades included (Honeywell) is only $93 (incl.) complete.  
3 new zones coming my way  :Biggrin:  
Now, what about the fancy new touch screen controller...

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## exotiic

Holy carp, I better have a talk to them about my pricing then, your getting them cheaper than I am with an account! Bugger

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