What is a multi-split?
Multi Split systems consist of one outdoor unit running multiple indoor units
We are often asked about installing multi split system air conditioners. Most people who have not yet done their research are quite rightly under the impression that they will be saving on cost compared to the price of buying multiple single head systems.
Makes sense. Having less out door units should save on cost right?
Well, that is not the case.
Check out our multi-split system installation video. It will make clear why these units cost more to install.
You can get an online air conditioning quote here
Lets look at a price example,
Mitsubishi Electric brand – multi split system option
You want air conditioning in 4 bedrooms
4 x 2.5 kw MSZGE25VA indoor units
1 x 8.0 kw MXZ-4D80VA outdoor unit
Unit prices excluding installation – $4960 inc GST
Mitsubishi Electric brand – single split system option
You want air conditioning in 4 bedrooms –
4 x 2.5 kw MSZGE25VA indoor units
4 x 2.5 kw outdoor unit
Unit prices excluding installation – $3915 inc GST
Difference in price – $1045 inc GST
As you can see the product it self is more expensive to have what seems to be three less out door units. Why?
Is it possible that manufactures charge more for the multi-splits because it is a “specialty item”? Multi splits generally cannot be purchased through bulk stores such as Harvey Norman or the Good Guys.
Is it possible that the single head units sell much more than multi splits making them cheaper to manufacture?
Either way, a multi split will cost you more to buy, and we haven’t even factored in the installation yet.
Why does the installation cost more?
Well, this answer does make some sense. With a single head split the most cost effective way to install the air conditioner is back to back.
A nice simple install. Indoor unit is located on an external wall and the outdoor unit sits directly behind it on the ground. Generally no more than 3 meters of pipe, electrical and duct cover is needed. This can vary depending on your particular situation but it is a price starting point.
Essentially, the closer the indoor unit is to the outdoor unit the cheaper the costs will be.
But with a multi split system the outdoor unit needs to be located hopefully in a central point in relation to the locations of the indoor units. So if 2 or even 3 indoor units are located on the other side of the house for example, that is going to add costs. The pipes would most likely need to be ran through a pitched roof or even more expensive, through a flat tin roof ( see video on this page).
As a guide, extra pipe is charged around $60 per meter
Lets look at an example,
3 x indoor units with an extra 8 meters of pipe per unit at $60 per meter.
8 x $60 = $480
3 x $480 = $1440
Difference in price – $1440 inc GST
Installation costs $1440 more and the multi units cost $1045.
Total extra cost to install multi-split system – $2485
Of course this is a guide only. Split system air conditioner installations have many factors depending on each unique situation, but you get the idea.
Combinations of multi splits:
Multi splits allow a combination of KW sizes to connect to the outdoor unit.
Some brands allow up to 8 indoor units to be run off one outdoor unit. What you need to do is very simple when deciding what size outdoor unit you will need.
Example:
2 x 2.5 kw indoor units will need a 5.0 kw outdoor unit
3 x 2.5 kw indoor units will need around 7.5kw outdoor unit
1 x 2.5 indoor and 1 x 5.0 kw indoor will need around 7.5 kw outdoor unit
Also, if you were to use 4 x 2.5 kw indoor units to service 4 bedrooms you could use an 8.0kw outdoor unit
But 4 x 2.5kw = 10kw…… I hear you say.
If all 4 units are running at there maximum capacity, the out door unit will give each unit only 2.0kw of output. But generally speaking, the indoor units are rarely running at full capacity. Plus, you may only need to run 3 units most of the time. Maybe the 4th unit is in a spare room and only need from time to time.
Pros and cons of multi split systems.
PRO’S:
- Only requires one outdoor unit.
Particularly handy for people who live in apartments and literally don’t have space for any more than one outdoor unit.
CON’S:
- If the outdoor unit ever has a problem and stops working, all the indoor units will stop working too.
If this happens in summer, having separate units will mean you will at least have air conditioning units working while waiting for a service.
- Costs more to buy and install.
Thank you for the great article. I’ve been studying about split system air conditioners. This is the first time I have learned about the Multi-head type and I find it very interesting. Please do keep on posting.
I loved how you mentioned that it will only require one outdoor unit. My husband and I are wanting to get an AC unit installed for our home. We’ll have to look into getting a multi-split AC unit for our home.
We have an existing Multi split system that can handle two indoor units. We want to add one more indoor unit. Would you recommend just adding another outdoor + indoor setup, or replacing the multi system to one that can have three indoor units connected? If changing the multi system, will it handle the old indoor units, or will they have to be upgraded as well? The current multi system sits on the roof of the room we want to install the additional indoor unit to.
Hi Vee, in terms of cost it would be much cheaper to install one new system than replace the multi unit. If it is still working well I would leave it as is.
Split system air conditioners use a quirk in the laws of physics to cool indoor air: namely, the tendency for liquid to absorb heat when it transforms from liquid to gas or vapour!
Thanks for the insight. Unfortunately my apartment strata has stringent rules on air conditioning units, sound, installation, etc and hence a multi split is my only option. Are there any other ways to reduce the $6.5k installation cost for a three head system since it’ll need its own power and piping? Timing of installation?
Hi Jeff, feel free to contact us to go over you options.
The only reason I can see to install a multi-spilt system if there is a lack of wall space outside to install the outside units (That is my situation in a duplex) but in this case, there appears to be plenty of room right around the house to install separate split systems.
Why would you go for a multi-system in this scenario?
Hi Theo, I agree. The client wanted the multi systems.
Great video!
We discuss this type of thing a lot at our public Facebook Group, “My Efficient Electric Home”.
https://www.facebook.com/groups/996387660405677/
Feel free to join in!
Tim Forcey
My girl and I need to look into new AC units, and the split system has come up in conversation a few times. The fact that it can run multiple indoor units from one outdoor unit seems like a great idea, and would fit perfectly for our new house.
We already have a twin head split system that needs replacing. There is no brand on it, was here when we purchased the house. Would the new unit be able to use old fitting etc?
Most likely you cannot re-use the existing pipes. Could possible use the existing electrical supply depending on the location of the outdoor unit.
When trying to work out what the right AC solution is for you and your home, it is overwhelming the amount of information the internet provides, all claiming “THIS” (which is something different to what you just read) is “the best”. Jason I found your info SO helpful. It was objective, clear and explained exactly what’s involved in installing a multi split system. The video was great too, thank you!
My wife and I need to look into new AC units, and the split system has come up in conversation a few times. The fact that it can run multiple indoor units from one outdoor unit seems like a great idea, and would fit perfectly for our new house. Thanks for the video showing how this is different, and why they cost more to install. Now we can make a more informed decision.
Thanks for listing a few pro’s and con’s for the split air system. However, I am bit confused with the very last bullet point here that says that costs are more because of buying and installation. Is this referring to the split system or having multiple units around your home? Either way, the split system sounds like it may be the best buy for my family in our current home.
Hi Doug
The costs are usually more because the multi-split air conditioners cost more to buy than the single head splits, strange but true! Also, the installation requires much more materials and labour to run all the pipes back to one central point as apposed to a back to back installation.
I really appreciate you talking about this, and listing the pro’s and con’s of a split system A/C! I was actually wondering if I should get something like this or not. But going off of what you talked about, I definitely should. Thanks a ton for the help!