Thread: Ducted whole house or wall splits ?

My 'take-home' so far is... You get what you pay for, - and that applies as much or MORE to the installation as the mechanical bits... (Most of the 'resonance' problem can be sheeted home to sloppy installation and positioning, they put it between two full-width trusses, not above the wall-braced truss I'd suggested. Saved them a few metres of ducting...)

Am getting unspoken 'directions' to go for a replacement Evap 'box', the "inverter" motor type, which I'm hearing is more reliable than the older induction.s (we went through THREE or FOUR of them in the first year, all under warranty...)

Family room is destined for a large, top quality wall unit, and we'll see about the rest later. - Fans on stands are....effective enough!

Balance of our windfall has been earmarked by SWMBO for a sliding side gate and a bit of fencing ...

Many thanks for the contributions and advice so far !

Originally Posted by rick130

3100kpa/450psi.

I agree re refrig.

Where I'm working ATM it's almost exclusively bar/club/pub refrigeration and Aldi and IGA supermarkets.

Lots of new Pythons and coolrooms although I've just spent 2.5 days running new air con drains at the ANU.
Whoever originally installed it haven't heard of Isaac Newton or this amazing discovery he made called gravity, they tried to make water run up hill without a pump, and from 13kw fan coils through 20mm conduit.

Did I mention it was 7 x 13kw fan coils through a common drain system that they did eventually upsize to 32mm electrical conduit run horizontally across the ceiling grid for 20m

Just being my usual stirring self... I've always thought that the higher the pressures in a given vessel/pipe, the more likely a leak, and when it happens, the more... spectacular... it will be for collateral - damage.

ONE exploding hydraulic hose in a lifetime is more than enough for me !

IF a system was to use - perish the thought - Propane/LPG, what would the equivalent pressures be ?
- 450 psi gives me the willies....

Originally Posted by superquag

Just being my usual stirring self... I've always thought that the higher the pressures in a given vessel/pipe, the more likely a leak, and when it happens, the more... spectacular... it will be for collateral - damage.

ONE exploding hydraulic hose in a lifetime is more than enough for me !

IF a system was to use - perish the thought - Propane/LPG, what would the equivalent pressures be ?
- 450 psi gives me the willies....

450psi is the test pressure we used on that job for R410, as I said before I've seen running pressures up to 600psi and it scares the willies out of me.

Some of these new turbo fan evaporative air cons are brilliant. Last summer I replaced a 30 year old Braemer drum evaporative for a turbo/fan at my mums and she loves it. Variable speed, thermo controlled, so much more efficient than the one it replaced and excellent value for money. We get mid forties here. The main thing with evaporatives is they change the volume of air in the area they are cooling about twice per minute. If you are getting humidity quiet often there is not enough venting. If you half open an external door, let it go and it slams shut, you need more windows open to allow air out. In my line of work I get into a lot of houses and some are like a sauna, windows are open but curtains are clinging to it! It's not the cooler, it's the operator.


The down side is on muggy days they will increase humidity, but you can turn the water off and just blow air through and that works rather well.
Also there is security issues as you have a lot of windows open.
Climbing up on the roof to service them is a pain in the butt, however the newer types are far less maintenance demanding than the older units were.


In our own house we have a ducted system (Carrier) we installed 25 years ago. It's been great, never even had it serviced, but they are far more expensive to run. They have to combat a lot of heat in the ceiling cavity so obviously that is down side compared to the wall type split systems. We have misters set up over the condenser which improves it's efficiency and it does not seem to cycle anywhere near as much when they are going.


If I were setting up again I would go with the wall type split systems and probably Mitsubishi units.


Cheers, Mick.

Originally Posted by rick130

450psi is the test pressure we used on that job for R410, as I said before I've seen running pressures up to 600psi and it scares the willies out of me.

And R32 runs slightly higher

I had a temperzone R410 unit with a clogged condenser cycling on the HP at 650 PSI a month or so ago.And another one with blocked strainers in the accuraters doing the same thing.Scares me as well.

Damn dangerous,but the greenies don't give a rats.

We recently repaired a large Fujitsu ducted unit,on R410, that had no HP switch,the condenser fan motor cap had failed and it blew a hole in the condenser coil.

Back to 134a for me anyday
Or for that matter R404a and its super high pressures

Apparently the CO2 stuff is scary too Paul, and it runs really high pressures, I just haven' worked on it yet, hopefully soon.

It vents through rupture discs into the plant room when the pressures get too high and scares the begeezus out of you as it happens pretty frequently.

IIRC the low temp rack discharge is partly cooled by the medium temp suction, so when the medium temp system goes down the low temp blows.

Aldi have been rolling it out and Woolies are now following.

Just replaced my crappy cheap ducted reverse cycle air conditioning system (10 years old) at home with a new system designed and installed by an air conditioning engineer who does work for the company I'm employed by. (I work for a Commercial Fit-out company)

System is a Daiken and is a 12.5KW unit with 6 zones.

It's absolutely brilliant ......I've been in Sydney for last three weeks and unit was installed in December.

Perth's had a run of very high temperatures with humidity which would have been unbearable for my wife and family since we built a house with traditional red bricks around 21 years ago and believe me they do retain the heat.

He does work for 12 Architects in Perth and Dakin is the brand he recommends as no1 though he will install some of the other mentioned brands as well.

Also check out that the cost of going to the next sized unit my unit (10KW system to 12.5KW) system cost wise was negligible between the units.
These new systems are also very energy efficient and mine has two sensors for monitoring temperature within areas of my home

As far as heating they are the most cost effective method available.

Its tough ??its all about the dollar and how much you are willing to spend however my brief was simple ?'design me a system that actually works using quality parts and will keep us COOL when its 39 degrees outside??.and he has delivered in spades.

Good luck with what you decide on either splits or ducted ....but as always this forum has some very KNOWLEDGABLE people and its been enjoyable following this post.

Cheers

Baggy

Originally Posted by rick130

Apparently the CO2 stuff is scary too Paul, and it runs really high pressures, I just haven' worked on it yet, hopefully soon.

It vents through rupture discs into the plant room when the pressures get too high and scares the begeezus out of you as it happens pretty frequently.

IIRC the low temp rack discharge is partly cooled by the medium temp suction, so when the medium temp system goes down the low temp blows.

Aldi have been rolling it out and Woolies are now following.

Haven't worked on any CO2 stuff,but yes it runs at very high pressures.It is used in Europe a lot.They use 134a for one part of the system,so i am told.Apparently there is a fair bit of it around,so the Bitzer guys tell me.