After-market diffuser for ceiling cassettes?

[completediv]

I am getting my ears bent in a very aggressive manner by the inhabitants of one particular office building serviced by multiple Daikin VRV 3 pipe systems and AHU supply with electric heater and humidification. Everything works as it should - data loggers used to prove temperatures and hum to occupants. However they will not accept blown air from the cassettes in either heating, cooling or fan only as they are far to sensitive. The building supply and extract does not irritate them - only the cassettes.

My question is this - other than blocking some of the 4 way blows on the cassettes, is there any cosmetically pleasing after market diffuser that can be fitted to further diffuse the airflow and shut the b******s up?

Many thanks for any advice you may have

[install monkey]

nah, setting modes can increase the airflow direction to blow accross the ceiling, only other way is jam some cardboard between the facia and the unit to block outlets towards troublesome staff- ive got the same thing with 70 vrv2 cassettes- typically concrete slab floor women want 28deg constant with no air movement, ive even resulted in taking the odd unit out of the group control and set it as a stand alone unit with no start command to stop the women complaining.
good luck

[SeanB]

A quiet word in a dark corner with a lead pipe did not work then........

Can you not arrange extra dummy cassettes fed from the alternate air outlet on the unit, to lower velocity. This then will move air, but will have a lower exit velocity and might make them happier.

[install monkey]

now the facilties manager turns the ac off during winter (9 months) and only runs it for 3 weeks of summer- to make the f***ers suffer!! haha

[Brian_UK]

I've seen a few offices where a clear perspex sheet has been fitted under the cassette outlets to force the air across the ceiling.

You will always have problems with cold air because it will drop off the ceiling line at the end of it's throw.

[frank]

We've had some success with the multi-nozzle type of diffuser from Systemair (http://www2.systemair.com/en-gb/scontact_us_1/systemair_products_2/online_catalogue_22/diffusers/nozzel-diffusers/sinus-a/sinus-a-125-l-ceiling-diffuser-1951)

They are not cheap mind, but effective.

Might be worth getting the tight git to buy a couple for a test in a small area.

[Slim R410a]

Hi Frank - How do you propose to fit those diffusers to a cassette?

Never seen or tried one of these but worth a look?? Cassette Deflectors http://www.jacsupplies.com/index.php?route=common/home

Another solution for the cassettes causing trouble may be to use 1 or 2 of the knockouts and take insulated duct to a diffuser/grille to an area where it wont blow a draft on anyone?

And/Or if local controllers are used, change the setpoint to be read from the remote sensor? (if in the height/area the staff are)

[r.bartlett]

We've had some success with the multi-nozzle type of diffuser from Systemair (http://www2.systemair.com/en-gb/scontact_us_1/systemair_products_2/online_catalogue_22/diffusers/nozzel-diffusers/sinus-a/sinus-a-125-l-ceiling-diffuser-1951)

They are not cheap mind, but effective.

Might be worth getting the tight git to buy a couple for a test in a small area.

How do you fit these on a cassette?/

It's the manufacturers who are to blame with poor design. The daikin 4 way under ceiling is a classic example of poor design. The airflow is really bad and they just don't seem to want to alter it... A simple fix would be to change the vanes to straight so you can blow directly out instead of them being curved so it always blows down no matter what...

[frank]

Hi Frank - How do you propose to fit those diffusers to a cassette?

Another solution for the cassettes causing trouble may be to use 1 or 2 of the knockouts and take insulated duct to a diffuser/grille to an area where it wont blow a draft on anyone?



Looks like you've answered your own question there Slim ;)

[Slim R410a]

Looks like you've answered your own question there Slim ;)

I seem to do that alot Frank :confused:

I was just going to propose using a standard 4-way/fixed blade grille in an (unoccupied) area.

[completediv]

Hi Folks

I'd like to apologise for not answering sooner (work got in the way) and to thankyou all for your comments.

Slim R410a - I'm going to get some more details on the JAC cassette delector and probably try one on test. I'll post my findings as to whether good or bad. If that doesnt shut the f*****s up I'm going for Brian_UK's perspex. I have previously used big sheets of hardboard which is effective, but looks like ****! I'll let you know if it quietens the little darlings!

[eggs]

http://www.jacsupplies.com/index.php?route=common/home


hi, Richard, the owner of this company taught me everything I know :eek:.

Give him a buzz, he is a mind of information and always has some new invention in progress. If you don't get a response he is probably in Australia, pm me and i'll contact him.

Alternatively Air conditioning Accessories in Leeds/Manchester sell his products.

Cheers

Eggs

[SeanB]

You thought of filling the coffee machine with decaf, and the water chiller with Prozac? The hardboard is cheap, and if you paint it white with a can of paint it will blend in with the white tiles.

[Andy AC]

I have used one of those deflectors from JAC before, and found it to be very good, solved our problem.
They attach to the filter grille on the cassette, so as long as the filter panel has proper locking catches it will be alright. If you have an older series MHI cassette with those silly spring catches it will be a problem as the weight of the deflector is too much without modifying the faschia panel.