Selection of AC Unit

[4xsama]

Hi,

We are looking to install an AC unit in our weatherboard house. Insulation will be complete by install time.

I have worked out we need a 13.25kw unit (living @ 81m2, 3 bedrooms @ 39m2).

It is an older house (1930's cottage) and preference is for ducted but what are the pro's and cons vs a multi head split.

Also, a rough idea on costs would be cool (pardon the pun).

Cheers.

[tricky4000]

We have a similar sized house I believe. We went for a ducted 14kW Mitsubishi Electric invertor system and that cost around $11K including installation.
Insulation is your best friend. It is surprisingly cheap to heat and cool our place and I think most of the thanks goes to lots of good insulation. Are you insulating the walls too?
Pros for ducted : Looks neater, one central unit (can be a pro), quiet, even tempature through out.
Cons for ducted : expensive to install, You will run 14kW unit everytime you turn it on.
Pro for wall hung : if you want to heat/cool one room you can, more control over different tempatures in different rooms.
Cons for wall hung : the don't look that great, could possibly cost you more than ducted, messy outside when you have many units.

I think those pros and cons are pretty onvious. Sorry.

There are many types of ducted split systems. You might choose to go a multi head ducted system so you have more control over individual rooms which can save you money and still have the minimal look. Definitely go an invertor and go for a unit with a 5 year warranty.

Tricks

[ErrolFlynn]

With split systems, you don't necessarilty need an external unit for each internal unit. Some external units are designed to be large enought to run more than one internal unit. though, you will need pipes running up the walls.

[dominicw]

Some additional points worth considering: Split systems is generally cheaper to run. Ducted systems can have an EER of around 3, whilst split systems can have an EER of around 5. EER is the ratio of cooling capacity output to power input. The higher the EER value is, the more efficient the system is. Also, there isn't a need to have doors open for airflow.