Single, Dual, or Total Zone Control

  • November 6, 2014
  • By MR COOL

A single MrCool ductless mini-split heat pump unit is designed to provide effective and efficient air comfort to a single zone in your home. What is a single zone? Don’t worry too much, because it’s a pretty simple concept. A single zone in the average home is just a typical room. Your kitchen? One zone. Your garage? One zone. Your living room? One zone.

I think you’ve got it.

What happens if you have multiple zones (i.e. – multiple rooms) in your home that you want heated and cooled? The answer is multi-zone installation. How does that work?

All you have to do is install a single MrCool unit in every zone you require air comfort. Not only will you get reliable performance, but you’ll be able to customize the environment in every zone to your personal desires.

For example, a kitchen can get pretty warm compared to the rest of the house when your cooking and baking. With multi-zone control, you have no worries. You can increase the cooling in the kitchen without freezing everyone elsewhere in the house.

Want to keep the bathroom warm on those cold winter mornings? Multi-zone heating will take care of that. Tick the heat up on the MrCool that services the bathroom, and stop freezing when you hop out of the shower.

For more information about all the mini-splits MrCool has to offer, check out this video where you can learn the differences between the DIY, Advantage and Olympus Multi-Zone series.

37 thoughts on “Single, Dual, or Total Zone Control”

  1. I have a 12 unit Apartment Building that I think this will be a perfect solution for. One of my questions is the remote control. I would need to be able to get replacement remotes. I think an excellent solution would be wall mounted remotes (to reduce breakage and loosing them). I would like to talk with someone about this as a solution to my HVAC for these buildings.

    1. Replacement remotes is something we can help with. Give us a call at 270-366-0457, ask for Daniel, and help however we can.

  2. I have a small ranch one level house with 5 rooms split into 1100 sq ft total space and I was interested in a 2 zone cooling system – one in living room and 1 in the master bedroom situated mounted on the wall in an effort to cool the one level 5 room house. Would this work for the total sq ft I have (1100 sq ft) and what would I get an 18,000 or something a little larger? Also, where in Mass are your products sold? Any assistance is greatly appreciated. Thanks

    1. This is something you could potentially do! You may want to size up the mini split, though, to something like our 27k BTU or 24k BTU models. The size of the unit your home needs is also dependent on your insulation level. There are also options with the air handlers available, as well, and how much square footage they cover. That is to say, converting your home’s cooling system to mini splits is not impossible. You can find more information here:, and you may be able to find a MrCool retailer near you on our “Where to Purchase” page.

  3. I have a small cabin (864 sq ft) and looking for 3 zone unit. I see buying 3 separate units is much less expensive than buying a 36k BTU 3 zone unit. What is the preferred method? 1 unit or 3 units to so 3 rooms?

    1. That is really up to your personal preference. The main difference is that three individual units would need to be wired separately while a single three-zone would only need one disconnect and breaker.

    1. Sometimes. The way that could work is if you installed a multi-zone capable condenser with a single-zone initially, and then added other zones later. There are capacity requirements you would have to observe with the single air handler on a multi-zone condenser though.

      1. Could you please elaborate? I have a 3 zone unit but only wish to install two heads for now. What do I have to be aware of? Also, can I disconnect and reconnect the DIY connectors once or twice?

        1. The attached air handlers must equal at least half of the capacity of the condenser in order to operate correctly. For example, if you had a 36k BTU condenser and four 9k air handlers, you would have to install two 9k air handlers to meet half of the condenser’s capacity. It is not recommended to disconnect the pre-charged line set once attached.

  4. I have two rooms that I would like to install a multi zone unit. Can you heat one room and cool another with a multi zone condenser and two head units?

  5. Hello, I would like to install one of your units in a large garage ( 32′ x 40′ x 18′ ceiling ) would you recommend a single head unit or would it be better to use a multi-head unit ? Would it be easier for the unit to heat and cool more efficiently with multiple heads ?

    1. For that space with that high of a ceiling, you may want to consider getting two units. Normally, a 36k would be a sufficient fit for a 1,200 square foot space, but since the ceilings are so tall, you may want to think about getting two smaller units. Climate, sun exposure, insulation, the amount of people normally in the space, and other factors also affect unit sizing. Take a look at for more information regarding sizing, or give us a call at 270-366-0457 for the best advice.

      1. Hello, thanks for the insight. When you say two smaller units do you mean separate systems or multiple heads ?

        1. I apologize for any confusion. I meant two separate smaller systems, as your space has extremely tall ceilings that would increase the BTU capacity needed.

          1. I have first floor and basement but the I needed shorter quick connect 16′ and 4′ since the tubing are so bulky foe longer ones.

          2. We don’t sell direct, so you will need to purchase a 16′ line set from one of our retailers. We do not have a 4′ line set.

          3. You would need an 18k air handler but yes, the configuration of an 18k air handler and a 9k air handler with a 27k condenser does exist.

  6. If we have a multizone 2 zone DIY, one unit in 2 separate rooms. Will the remote in 1 room reach to the 2nd room’s unit and potentially control the temperature in the 2nd room inadvertently?

    1. It should not. If the remote does interfere with the other air handler, please give us a call at 270-366-0457 as quickly as possible.

  7. I have 2 Mr Cool units in my house. One upstairs, one downstairs, each have a different BTU, but use the same outdoor air unit. My question is: Do I need to have a remote (thermostat) for each, one for the downstair and one for the up, can I just use one remote?
    Thank you,

    1. If you are using the physical remote, you should use one per air handler. You can, however, use the Smart HVAC app that you can download on your phone to control both air handlers from the same device.

  8. If I install a two zone 27000 btu can I put one head on now and add the second head after my addition is added on later thanks

  9. I am noticing that in my MrCool mini split multi head system if one unit is demanding heat, the fans on the other 3 units come on resulting in some rooms getting too hot. Is there a way to make each air handler fan come on independent of the others? For example, my living area is a large space and each time it demands heat, all the bedroom unit fans come on and push out heat although those rooms are already above the set temperature.

  10. Is it possible to install just a 1 air handler but higher BTU for a 2-3 bedroom house one level?
    Fir example a 24-27 BTU on a 900SQFT house? Or do I still need a few?

    1. You could do that as long as the entire house is open air, or you don’t really care about the heating or cooling not reaching spaces that are closed off. Since the multi-zone mini-split is ductless, it will not be able to heat or cool a location that is closed off to it.

  11. I bought a 48k BTU 5 zone condenser, but only installed a 12k air handler. I already open the king valve, without installing the other units. Is this a problem in the future?

    1. We recommend that you install at least 2/3rds of the condenser’s capacity in air handlers before use. Not doing so may negatively affect performance and further installations.

  12. I have installed a 4 unit mini-split system. Two of my unites are located in upstairs rooms that are near each other. When I use the remote in one room it also activates the unit in the other room. Is there any way to stop this so that they can be used independently?

    1. You may be able to get more direct control out of these units separately if you connect them to your phone and control them through the Smart HVAC app.

  13. Hello, is there any issue with the combined BTUs of all the air handlers being higher than the condenser? I’m building a very highly insulated home with fairly small bedrooms. I’ll probably only need 3-4k BTUs in the bedrooms and 18k in the main open space. I wish there were smaller air handlers for this purpose. If I did a 5 zone 48k condenser and 9k+9k+9k+9k+18k air handlers, would anything go wrong except not getting 54k total output? Thank you

    1. Hi,

      Yes, essentially the only issue would be that if all air handlers are on at the same time, you would not get the full output of the air handlers combined, just up to the condenser’s BTU capacity. If you were able to shut one of the air handlers off in the bedroom when not in use, that would allow the rest of the air handlers to function at full capacity. Using the system like this will likely not directly damage the condenser, but the increased strain may affect the system’s performance in the long run.

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