LG ducted split

[Abe]

Ill be fitting an LG split ducted system in soon..........well in due course.

Since this is my first I need a few pointers, the ducts.

Im using flexible ducting, I need a source..........Frank do u know of a localised supplier.

Second..........its going into a bungalow.........Will the fan noise be tolerable.

Im hoping to have 5 feeds , each going into a different room. Unit is LG's 10 kw Ducted split, single phase.

Abe

[Abe]

According to the manual the specs are:

Air Circulation Indoor

32/29/26.5 @100
(m3/min) @Pa Static


Sound Indoor

58db (at 1.0 m)

Would be intresting to hear from someone who has installed this in a domestic environment

[eggs]

Aiyub, for my ducting i use CCL a lot.
They have a branch in Leicester 0116 255 6044.

As long as you size your grilles and flexi ducts correctly, noise will be no issue at all.

Cheers

eggs

[frank]

Sound Indoor

58db (at 1.0 m)

Hi Abe

this is quite noisey. Have a look at any of the noise levels quoted for a wall unit. mitsi is 22dba, daikin is 23dba, so you can see that 58 is .

Im using flexible ducting, I need a source..........Frank do u know of a localised supplier.

I've got a company that supplies this sort of material. You've got my number and I can beat CCL on price.

Second..........its going into a bungalow.........Will the fan noise be tolerable.

Any noise during the day will be tolerable unless you are sleeping on the couch (maybe after a few beers as in my case ) but during the night noise become a problem. One tip - don't make any promises to the client about how quiet the system will be - you leave yourself open to problems. Noise is peculier to each individual - what I might find quiet may be loud to you - etc

How will you suspend the unit in the roof void? direct to the joists? suspended on drop rod? any anti vibration mountings?

Noise can be transmitted in two ways from ducted systems

1) Ductbourne noise
2) Breakout noise

Duct noise can travel down the inside of the duct and appear at the outlet or grille

Breakout noise is what you hear adjacent to the unit (on the outside) i.e. you can hear the fan humming away in the ceiling

Both have different characteristics and have to be dealt with in different ways. Duct noise can be addressed with inline silencers or attenuators and breakout noise can be treated by wrapping the duct or fan with insulation.

Let me know if you need more info.

[Karl Hofmann]

Abe,
I'm interested to see how this works for you as I intend to do the same in my own house. Problem is do I fit a ducted unit and only be able to control the temperature in one room, or do I shell out for compact cassettes in each room. That noise level does (On paper) seem pretty high, but I suspect that very few of us could actually say what 58 dB sounds like.

As Frank said, never make promises about noise, never let them pin you down on that one, there are some awkward buggers out there. On the other hand, my wife can sleep inches away from an old window rattler, but that is enough about my snoring

[Temprite]

If an aussie is qualified to comment

I agree with eggs.

Havent put in as many ducted units as wall splits.If you use a ductulator it is quite easy.Generally if the ducting is correct there will be no problems. Seen a few units with inadequate return air ducts and grilles, then you get some noise.

Although it is LG.........

Long live Daikin.

[frank]

Generally if the ducting is correct there will be no problems.

Hi Temprite

This only applies to velocity noise which is quite different from duct bourne noise or breakout noise.

Duct bourne noise is the sound of the fan travelling down the inside of the duct and appearing at the grille or register. Velocity noise is the sound of the air moving in the duct.

[eggs]

Aiyub, what you want is "Tecsonic 400s" from CCL. it is an insulated flexi duct that incorporates a perforated interliner so that your felx acts an attenuator
I would guess from your limited information you will need 225mm ducts. For me to buy this from CCL it is appx £55 for 10m.
Next make sure you grill boxes are also internally coated with "Pyrosorb" an accoustic insulating foam, about £10 for a 2mx1m self adhesive sheet.
then to finally kill off any remaining noise spend a few extra £££ on some good diffusers (appx 350x450 neck size, so they fit between the joists) with internal baffle plates.

If you get any noise complaints after this lot, petrol bomb the house and start again, using daikin , Frank will get you a good deal.

Cheers

eggs

[Abe]

Thank you all for your " valuable input"
Ive printed it all out and will incorporate your advice.

The LG system has a 5 branches plenum............So I can provide for chilled air sources to 5 areas.........

And return air is again 5 branches........

So one system in the room space...........out of view.........

Only got to tackle this noise problem........

But I will keep everyone posted on how I get on........

Right now putting in cassette systems...........

Last remaining R 407C units...........Yes I know how I hated them.........But couldnt resist the prices!!!

[Temprite]

Last remaining R 407C units...........Yes I know how I hated them.........But couldnt resist the prices!!!

Aiyub.

When you say last remaining 407C units are they going to 410A now?

All the ducted units we use are either 22 or 407C only some units(not ducted) are on 410A

22 is getting phased out but sounds like UK is way ahead of Aus in regards to this.

[frank]

The LG system has a 5 branches plenum............So I can provide for chilled air sources to 5 areas.........

And return air is again 5 branches........

Thats all well and good Abe but how will you control the temps in different areas from one ducted unit with one controller?

Me thinks problems are a comin'

[Abe]

Temprite


407 C is as good as dead now........
Its only 410 A now.........

[rbartlett]

i fitted two of these (maybe the 14kw version) in a busy telesales office.

I thought they were too noisy -I would NEVER EVER fit one in a home

cheers

richard

[Peter_1]

Thats all well and good Abe but how will you control the temps in different areas from one ducted unit with one controller?

Insert a simple open/close butterfly (slow action) in each supply branch, controlled by a cheap mechanical heating/cooling thermostat like the EBERLE KLR-E 525 55.

Then bypass over the indoor unit a pressure controlled VAV box (Trox, Grada, Nailor...)

Just do a Google search on 'bypass pressure vav' and you will find thousands of pages.

We have done it with at least 10 installations.

My son even tried for his graduate project to communicate with the Mitsubishi controllers so that the signals from the indoor units could be interpreted/controlled by one single controller.
But it was far too complex but all the zones could then be controlled by one controlled, time dependant with a year clock. This isn't availiable for the moment with any manufacturer.

But the solution I suggest now is easy, relative cheap and it works fine.

If you can use a water cooled indoor unit, then it's even much easier: just reduce speed of the fan of the indoor unit. There are special pressure actuated controllers for this, again....relative cheap.

[Abe]

Thanks Marc for the warning about noise...........Frank pointed it out as well.

At least now I wont go blabbing to the customer that unit is quiet......but tell him its noisy.......He must decide .

[Abe]

If an aussie is qualified to comment


Although it is LG.........

Long live Daikin.

There was a period I " went off LG" but Im coming back........I started using Mitshubishi Heavy Industries.......( unbeknowingly) I thought Mitshibishi was Mitshubishi Electric.............until someone pointed out the difference.

What a nightmare...............Try programming the remote controller.........You have to ring technical. then the guy on the blower talks you thru the parameters.

Step one........press set. step two............etc etc.

And all to change the indoor unit fan speed!!! I wanted it on High for High ceiling..........

Customer said not enough air flow........

On the LG all u do is flick a switch on the controller.

I like the sheer simplicity of the LG...........thats all I need..........nothing razz ma tazz or jazzy.........

Must work cleanly and simply..........for 12 months anyway!!

Mind you I have had no comebacks on a single LG unit Ive installed past three years........except for one dastardly 10 Kw wall mount..........R407.

But that I sorted...........with Richard Bartletts help!!!

Thx Rich.........

[chemi-cool]

Hi abe,

Can you suggest the client, a few mini splits instead?

It will eliminate the noise problem and will be easy to control.

Chemi

[Abe]

Im going to give it a " miss" contemplating a ducted split in a domestic environment.

I remember I went to a trade show last year some time, was not a fridge show, but they was a company that did a moulding for a ducted indoor unit.

Xpelair or something..............They do a whole house ventilation system eith cooling incxluded.........

Cant for the life of me think of the company.

Oh well. back to the drawing..........ahem,. Google board!!

[eggs]

Is that the "Centre Cool" they used to sell at Thermofrostcryo?

cheers

eggs

[frank]

Is this of any help Abe? http://www.domusventilation.com/asse...CatOp05_06.zip

[Abe]

Is this of any help Abe? http://www.domusventilation.com/asse...CatOp05_06.zip

Frank,

Its a great resource site, but ermmm no, its not what I was looking for. But they got some good ducting stuff in there. Worth having that manual on the shelf. Wonder if they will send me one ?

I think Marc's American product is more like what Im after. The Unico stuff.