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rod1949
17th October 2005, 04:11 PM
Ya see these ads for fully ducted air conditioning systems (I’m referring to refrigerated/reverse cycle air conditioning).

I question the energy/consumption efficiency $ running costs of a whole house ducted system against having a single room unit installed in each of the main rooms of the house.

Now the ducted will do the whole house whether you are using the room/s or not and admittedly you can close off the vent if the room/s are not in use, but the unit is still being powered by one large horse powered motor.

Where-as a single room unit is usually of a much smaller horsepower, and is only in use whilst the room is in use, thus giving greater control.

To me the single room unit has got to be the more energy/consumption $ saving efficient.

Its like comparing two cars, one with a 5lt engine and the other with a 1lt engine, with the 1lt being the most efficient.

What are your thoughts and experiences?

Trav
17th October 2005, 07:19 PM
I reckon that one big unit will be more economical. But it depends on how many rooms you will run at any one time. If you are only running one at a time, the smaller units will prob be cheaper. But if you are running 2 or 3, I think the big bopper will be the way to go. And speaking from experience (ducted heating, not cooling), ducts are the way to go.

Trav

Harry72
17th October 2005, 09:40 PM
Its like comparing two cars, one with a 5lt engine and the other with a 1lt engine, with the 1lt being the most efficient.
Yeah thats true... but when the 1st real hill comes up the 1lt will strugle and suck heaps of fuel the 5lt will just putt up the hill using only slighty more fuel than being on the flat.

savage
17th October 2005, 09:43 PM
G'Day,

here at home we have 1 of each, ducted unit for the upstairs, split for the down stairs and a single unit for the family room(converted garage). We find running the two main units compliment each other and they are not running flatout all the time, but cycling less frequently as the temperature is more controlled and each unit is not as "stressed" as when used as a stand alone unit. What I mean by "cycling" is the fan is on more than the refrigeration as the air is more evenly cooled/heated through out the house, these are my thoughts and experiences, a fridge mechanic or the like may not agree!...
savage(Eric):)

Ashore
18th October 2005, 12:06 AM
Rod
The more efficient system is the larger one

Some points however to consider

With a Split system will you Always have the door to that room closed, never leave it open when the unit is running

Is the installation going to be unsightely pipes have to run to each evap unit , can you hide these in the walls

Is running 3 x 2 hp units more efficient than 1 x 6 hp unit ? No

Each unit has its own filter to clean

Going from a cold room to a hot one,

You cannot simply shut the vent to an indivdual room on a ducted system
unless you want to spend mega bucks

Inverter systems are designed to run more efficently

Do you have room and axcess for a ducted system in your ceeling space, floor vents are not recomended for fully ducted systems

What type of insulation do you have in your roof cavity

How much do you want to outlay , single split system single room at 2.5 hp $2000
total 3 bedroom house ducted $8000 to $ 10000


Do you have 3 phase power most large ducted systems require this ( can be a good excuse to get it connected for those 3 phase tools you will need in the future)

Do you realy live in your house or just one or two rooms

Some split systems are better in bedroom , have the ability on sleep control to drop the temp 1 degree each hour

Split systems also can have the thermostats in the hand control so that the desired set temp can be monitered where you are in the room , not just one setting for the whole house

However if running cost is your critea go with the ducted system plus you also get the desired temp reached quicker, weather heating or cooling

Initall cost then split system for only the rooms you use

We have both as the extension I put on has a skillion roof so this section of the house is split system ( av room , family room, laundey and bathroom)
and the rest of the house 2 bedrooms , dining, kitchen, study,Lounge and bathroom are ducted


Hope this helps ( roll eyes )



The trouble with life is there's no background music.



Ashore

Daddles
18th October 2005, 01:36 AM
I have a very cheap aircon here - I never turn the rotten thing on, sounds like a Jumbo's having kittens in the lounge :eek:

Richard

Skew ChiDAMN!!
19th October 2005, 08:41 PM
One other thing with split systems: give some serious thought to where the header unit is going to be mounted!

They really should only be mounted on external walls, to both minimise pipe runs to the compressor (external unit) and 'cos the header needs drainage!

If mounted on an internal wall, a small "sump-pump" is normally used to pump the water into the ceiling cavity, thence into normal drainage. Unless prior allowance was made during wall construction. This pump's only the size of your cheap aeration pump for goldfish tanks... and doesn't last forever. If you don't pay attention and it goes *POOF*, the first you may know about it is the damp stains coming through the plaster. ;)

With a ducted system, the header is usually mounted directly onto a tray in the ceiling cavity, doing away with the need for the pump. If only they were as quick & easy to install as a split... :D