Introducing the MRCOOL Universal DC Inverter Heat Pump

  • December 6, 2019
  • By MR COOL

MRCOOL is proud to introduce the innovative and advanced MRCOOL Universal DC Inverter Central Heating & Air Split System. This sophisticated inverter split system includes the Universal condenser, air handler, and support components necessary to maximize your home air comfort.

What is the MRCOOL Universal DC Inverter?

MRCOOL DC inverter technology is designed with an inverter compressor and DC motor, together creating a comfortable and energy-saving experience to heat and cool your home. This system controls compressor motor speed and regulates temperature at the same time to avoid any rapid fluctuations in temperature and energy usage. Compared to previous generation technology, this system has many innovative features that provide more energy efficiency and save you more money each month on your energy bills. 

This system has many benefits including:

  • 1. increased efficiency
  • 2. rapid heating and cooling 
  • 3. quiet operation
  • 4. reduced operating cost
  • 5. reduced energy waste
  • 6. compatible with most third party thermostats including WiFi/NEST

Traditional condensers are heavy and take up a lot of space due to their wide and boxy nature. The new MRCOOL Universal DC Inverter System’s slim design takes up a fraction of the space traditional condensers need. This makes it ideal for installation in various locations outside your home — even tight spaces. The exterior has two fans and displays the MRCOOL logo with a modern white finish, capable of blending into any home’s design. It’s compact and ideal for zero lot line homes, strict sound restrictions, conventional installations and unit replacements. 


Do you rely on expensive propane or fuel oil? No gas furnace is required for the outdoor condenser to operate and reach its maximum performance. Tradionally, air-source heat pumps generate ineffective heating capacity in severe cold. The MRCOOL Universal is different. This next generation all-electric heater can operate in below freezing and below zero temperature conditions that would literally freeze regular heat pumps. Plus, the MRCOOL Universal has intelligent defrosting technology so you do not have to worry about unit safety and capability in the winter months.

The exterior is made to withstand harsh elements. It will stop damaging debris from entering inside the unit and causing damage. Therefore, ensuring that your outdoor condenser unit will last for a long time.

Air Handling

The Universal indoor air handler’s modern and flexible design provides the versatility for installation in a variety of places and in multiple positions. This system adopts 24V non-communication control technology between condenser and evaporator. Because of this feature, the system can be adopted to any third-party 24V air handler or thermostat other than the included air handler. This allows for flexibility in choices and makes the indoor unit easy to replace if ever required. Plus, should you wish to take advantage of all the benefits that the Universal condenser can provide without replacing your existing air handler, the non-communicating capability ensures that is possible. 

As an additional accessory, this system can accommodate an auxiliary heat strip. 

The MRCOOL DC Inverter System takes a new approach to heating and cooling by offering an ultra-wide operating temperature range. This heating and cooling system adopts two-stage enhanced enthalpy technology to ensure strong heating capacity even at extremely low temperatures. This maintains stable system operation and heating performance at extreme temperatures. It can heat at 100% capacity at – 5 degrees Fahrenheit, even with outdoor temperatures as low as -22 degrees Fahrenheit. It can cool in outdoor temperatures as high as 115 degrees Fahrenheit. This allows your home to maintain an optimal temperature without extreme energy usage causing high energy bills. 

To enhance the safety features of this system, the MRCOOL DC Inverter System incorporates many intelligent protection functions. 

Installing the MRCOOL Universal

An HVAC pro needs only conventional HVAC tools to install the MRCOOL Universal. However, we added special fittings that make possible installation with MRCOOL No-Vac Quick Connect lines. By using the Quick Connect lineset and fitting, there is no need to do vacuuming while installing your system. This makes the installation process fast, easy, and at a lower cost. 

The MRCOOL DC Inverter System comes in two models — a 36k model and a 60k model. Each system comes with a condensing unit, air handler and necessary parts for installation. The 36k model can cover a 24k to 36k BTU capacity range and has a SEER rating of 20. The 60k model can cover between 48k and 60k BTU capacity range and has a SEER rating of 17.5 to 18. Both models are heat pump systems that can produce cool air and heat for year round usage. Additionally, both models use environmentally-safe R410A refrigerant, which is chlorine-free to help prevent damage to the ozone layer, and are ETL and AHRI certified. 

MRCOOL is dedicated to providing high quality and affordable HVAC products to North America. The MRCOOL Universal is an excellent example of that commitment. The MRCOOL DC Inverter System has an extended life and requires lower operating costs compared to traditional HVAC systems. You will also find that it will require little servicing and maintenance during its lifespan. We are proud that this system works hard to offer you optimal comfort while keeping energy costs to a minimum.

Interested? Find out more about the MRCOOL Universal here

Want an Independent Review?

Check out an independent review of the Universal here.

262 thoughts on “Introducing the MRCOOL Universal DC Inverter Heat Pump”

  1. Most inverters run 20% (or even less) infinitely to 100%. The 36k above is listed for 24000-36000, but shouldn’t that be more like 6000-36000?
    Also what are the decibel noise ratings of the equipment?

    1. The 24k-36k range is not indicative of the inverter range. Rather, the current Universal model can be set to operate broadly as either a 2 ton or a 3 ton condenser. The decibel rating is 60dB(a).

  2. How much does the MRCOOL Universal DC Inverter Heat Pump 4 ton unit cost?? I live in Western Kentucky do you know of any installers in that area??

    1. The MSRP of the Universal is $2,859.00, though independent retailers may vary in price. If you live in Western kentucky, local dealer,, has a preferred contractor list that can help you with finding an installer.

  3. Hello my name is CJ I am a Hvac contractor in AZ, I have a trane 7 year old split system. Can I just use the condenser for my current unit for the capacity control. My current condenser is a two stage trane non communicating unit. My air flow in the furnace has two speeds and I have a zoned system. I feel like this would work great if I could just install the condenser.

    1. The Universal condenser is non-communicating, so it can work with many different air handlers. Since you’re a contractor, give us a call at 270-366-0457.

  4. I live in Havre, Mt. I would have to say after watching the video of Grand Forks that our weather is very comparable. We are in the North central part of our state, 40 miles from the Canadian border. My house is 3900 sq ft. Would this system work?

    1. The Universal is only currently available as 2 or 3 ton system. Larger systems will be coming out later this year. However, even a single 5 ton unit would likely be insufficient for 3900 sq ft. A house that size would be best served by two separate HVAC systems.

  5. Does this unit support a dehumidification mode? If it does what thermostat do you recommend to work well with this?

    1. The Universal does not have a dedicated dehumidification mode. However, since it is a heat pump it will dehumidify as a normal part of operation.

      1. Please know that there are others of us out here that would love to buy this today if a down flow air handler was offered by Mr. Cool!

  6. Thanks for coming out with this right AFTER I bought a traditional 4ton HP. We have had one of your mini splits in our bed room for years and LOVE it. Would have been nice to upgrade the whole house to your central unit. Watched your video on this heat a house all night at -20F and been reading up on it. Seems like solid a product. The DIY lines would have been nice on my project too. We live St. Louis, MO seems like this would never use back up heat. Keep up the innovation and pricing!

    1. The Universal condenser can be connected to an existing air handler, if that’s what you’re asking.

  7. Have a 40 year old 5 ton cooling Rheem unit with a 80% gas furnace in Long Island New York. Do you make a McCool system to replace it?

  8. What size universal system would I need to replace my existing traditional gas furnace and A/C system? It is a 2,100 square foot home that is 25 years old.

    1. Probably the 4-5 ton model, but it is difficult to say for sure without knowing more about your home and where it is located.

  9. I trying to completely understand that I could use a Mr. Cool condensing unit with my current Forced Air furnace utilizing that current inside unit plus current line set, A-Coil and simply have it vacuumed and charged locally??
    Is there an advantage to using the Mr. Cool indoor air handler? My current condenser is shot and I’m looking for a quality replacement. Been in home 30 years and started with Carrier high efficiency unit, that was replaced with a Goodman(junk) whilst the forced air unit has remained the same
    One last thought/question, if using Mr. Cool package(outside unit and needs it handler, can the currently installed line set be utilized with local vacuum and charge?
    Thank you!

    1. So there is a lot in this question.

      When it comes to pairing a MRCOOL unit with your existing system, there are a couple things the installer would need to know. Does your current A-Coil use R-410A? Older coils often use R-22. MRCOOL condensers can’t work with coils that use R-22. In the case that you have a coil that uses R-22, you should probably replace it regardless of whether you match it with a MRCOOL product or not. All new condensers are going to use a refrigerant other than R-22, and none of them will work with an R-22 coil. On the other hand, you should be able to keep your existing furnace.

      For a package unit, it doesn’t matter what coil you have, since a package unit wouldn’t connect to them anyway. Packages units, MRCOOL or otherwise, have everything they need inside a single cabinet (i.e. – the ‘package’). The package unit would not need to be vacuumed or charged. However, it sounds like your current setup is a split system. If you switched to a package unit, you would likely have to modify the duct work.

      Dwight, I hope those answers have been helpful.

  10. So is the condenser variable speed or two stage? What is two stage enthrall? Lastly what is the running wattage for 2 ton at rated capacity? Thank you!

    1. The Universal is a variable speed compressor rather than a two stage compressor. I do not know what you mean by “two stage enthrall”. The minimum ampacity the 2 ton capacity is 18 amps.

      1. Is the variable speed controlled from the air handler and compressor itself? I ask because setting up thermostats in the past I’ve had to select if the heat pump was one or two stage. If I understand correctly this will work with most thermostats. We have an Ecobee now and I’m interested in putting this system in to replace our current unit and would like to keep this thermostat.

    1. We will definitely be announcing here and on social media when our Universal 5 tons start shipping!

  11. I live in New Jersey I live in New Jersey have a 14 by 70 trailer thinking of mrcool will that be sufficient for heating and cooling of my home what unit do you suggest

  12. Where can I find technical documents on this model? I might be missing something, but I’m not seeing any spec sheets similar to what is available for your other equipment.

  13. Hi – 1. For the upcoming 60k universal unit, is there a matching 18 seer air handler? If so, what are the airflow connection options and are multi-angle photos available?
    2. For the 36K unit, are they stackable? If so, is there a 72K 20 seer air handler that could accommodate two 36K universal units?
    3. Is a dedicated power source required for the 8-15kW heat strips? What voltage/amperage ratings do the heat strips require?
    4. What percentage of heating capacity is available at -22 F for the 36K and 72K units?


    1. Yes, there will be an air handler that will accommodate the 4/5 ton universal condenser unit. It will be the same configuration as the present 2/3 ton unit- upflow, left side horizontal. We do not have pictures yet.
      No, the condenser is not stackable and there are no options for any other configurations.

      Yes, a separate 220v circuit is required for the air handler. When a heat strip is used the amperage will be determined by the heat strip and that circuit will also power the blower and control board.
      The 8KW heat strip requires a 40amp 220 circuit, the 10 KW requires a 60 amp. The 15 KW cannot be used in the 2/3 ton air handler, however it requires 2 – 220 v circuits, a 60 amp and a 30 amp.

      The 36k is approximately 50% effective at -22. The 60k is approximately 50% effective down to -15.

      1. Thank you, great information. So I assume the 20 kw heat strip used with the 4/5 air handler would require 2 60amp 220 volt connections?

        1. That is correct, although it is only supported through the 4/5 ton air handler. For a rule of thumb for these heat kits you can typically assume that every 5 KW you will need 30 Amps. 5 KW is 30 Amp Breaker, 10 KW is 60 Amp Breaker, 15 KW is 60 Amp and 30 Amp Breaker, then 20 KW would be two 60 Amp Breakers.

  14. I have a 1500 sqft home in CA (95403). Winters are not harsh and summer tops off in the 90’s. I received an outrageous bid to install a traditional 3 ton HVAC system. I am going the MRCOOL route instead. Will the 2-3 ton universal model be sufficient or should I wait for the 4-5 ton model?

    1. If you’re just switching out an existing 3 ton system with the Universal in a 3 ton configuration, you should be good to.

  15. What’s the cost of the 60K unit with air handler? I’m looking to replace my old r22 heat pump with 20 KW electric furnace that’s 30 years old. I like the 36K unit with air handler but it might be just a bit too small for our home we have about 3,500 to 4,000 sq feet. Please email me the cost.

    1. Hi, Daniel. We do not sell directly to consumers. Dealer price can vary. Could I forward your contact information to one of our dealers for a follow-up?

  16. Can you please explain how the system takes advantage of the variable speed compressor and fans to provide better comfort and efficiency. Ideally, it seems like a variable-speed compressor would run at varying speeds depending on indoor and outdoor temps and would coordinate its operation with that of the air handler fan. Since the condenser and air handler do not have any additional lines of communication other than standard signals from a thermostat I’m wondering how the two coordinate their operation?

    1. I’m also wanting to know. I’ve installed the unit and I did not see anything in the instructions detailing the variable speeds.
      Upon running the unit I do not see any variance in the speed. I’m a bit disappointed right now.

  17. I would like to buy a 4 ton MRCOOL Universal Series DYI but I need it in a downflow. My system pulls cold air from my ceiling vents and heat vents are in the floor. My current system is located in the garage. Is there anything that can be done to convert to downflow?

      1. I’m not a good HVAC Tech. I am confident I could install the DYI Universal system. Don’t think my skills are enough to reverse the blower motor. Could you guys keep us downflow guys in the loop as to when you are going to make the universal in a downflow. Thanks

          1. I need a downflow as well. Is this available yet, or do you have instructions available to do the conversion??

  18. Hello.
    I am slightly confused on the thermostat wiring… both the indoor unit and the outdoor unit have thermostat terminals. Are these terminals meant to be shared by one stat or am I missing something obvious. My concern is that both units putting out 24v could result in a phase mismatch since they are from different circuits. Is there a document discussing and spelling out thermostat wire up? The install manual does not cover this.


  19. Can I use any 5 ton evaporator coil with the quick connect line set or do you have a suggestion to assist in modifying an existing forced air furnace?

    1. The only products we have that are designed for use with the Quick Connect line set are the Universal condenser and air handler.

      1. What would you recommend for install when an existing has furnace with air handler is already in place? An additional air handler does not make a lot of sense and I do not have room for it.

        1. We can’t argue with you there. The Universal can work with an existing air handler and gas furnace. You just couldn’t use the Quick Connect lines on an air handler not designed to connect to them. Your best bet would be to have a pro connect the Universal to your existing air handler and furnace.

  20. When wiring the power supply to the condenser, will the air handler be fed off the condenser or is it two separate power sources?

    1. The air handler gets all its power from the condenser. Edit: This is incorrect! The air handler would need its own circuit. We get this exact question a lot for our ductless mini-splits, and those do get all their power from the condenser. So, to clarify, the Universal air handler does NOT get its power from the Universal condenser.

      1. Wait, what? The air handler gets ALL of its power from the condenser? Isn’t that completely different from a traditional single stage heat pump system? My traditional air handler get power from the circuit breaker.

        If in fact the AH get’s ALL it’s power from the condenser then that may explain my next question. How do the Condenser and AH communicate to make sure they are both running at the appropriate speed?

        Third question, how does the system determine the speed it should run? In other words, how does it know heat load?

        1. No, it doesn’t. I have corrected the previous answer. We get that exact question all the time related to our DIY mini-splits, and that is why the incorrect answer was provided.

          The Universal air handler would need to be wired separately like any conventional central air conditioning system.

          The variable-speed of the system refers to the compressor operation. The air handler connected to a Universal condenser does not necessarily have to be variable speed. The Universal takes its cues from the thermostat. The compressor operates at a lower cycle so long as it is maintaining temperature. When it stops maintaining the set temperature, it will ramp up.

          Sorry for the confusion!

          1. Your system is “non-communicating” so I don’t understand how a VARIABLE speed air handler would “know” what speed to run when your condenser unit is taking cues from the thermostat. How is the speed of the air handler controlled?

            In other words, I’d like to understand how the variable speed air handler, the universal condenser and the thermostat all work together to determine the respective speeds of the air handler and condenser. Please be as detailed as possible.

            I also have a separate question below which is not yet been answered.

            Thank you.

          2. The MRCOOL Universal air handler blower is not the same “variable speed” unit as some other units. The only adjustment available is to set the air handler for either 2 ton air flow or 3 ton air flow. There is no other adjustment. The condenser has electronics built into the board that allow it to produce the stated capacity (either 2 ton or 3 ton) under different operation conditions. It will adjust compressor speed and condenser fan speed to produce the BTU setting. The thermostat functions just as any other HVAC thermostat would.

          3. so sounds as the indoor air handler blower is going to be running alot more with this than on a traditional system ? as the tradition runs full capacity till satisfied and shuts off, the variable speed runs more at a lower capacity to “hold” or maintain the set point thus causing indoor motor to run more?

          4. And another one,, How doe the outdoor unit know it is not maintaining temp and to “ramp up” as the only communication it has with the thermostat is either an open or closed 24v circuit for heat or cool ?

          5. The condenser starts at a low operating level when it receives information from the thermostat. If it doesn’t meet demand in a certain window, it ramps up automatically.

  21. how many watts does the base pan heater use? Also does the heater cable turn on and stay on or does it cycle on and off with defrost cycles? Thanks.

  22. When the 36k system is set for 3 tons what is the lowest BTU rate it can flow and what is the acceptable total static pressures for all flow rates?

    1. The Universal system does not function like a mini-split. It does not have a variable BTU output. When set for 3 tons it will produce 36,000 btu and it will adjust compressor operation depending on actual load and temperatures to produce the rated capacity. The air handler is designed for no more than 0.5 ESP.

  23. I have an electrician coming to wire up my Universal system. I installed the 8KW auxiliary heat strips in to my air handler which has its own breaker. These strips then connect to a wiring harness that hangs off the air handler board. I have a few questions about these:

    1. Do I have to have my electrician wire directly to aux strips breakers from the panel box or does the aux strip get all of its power from the wiring harness that I plugged it in to? The installation papers that come with the strips aren’t clear about that.

    2. What controls the operation of the auxiliary heat strips? Do they automatically kick on when outdoor Temps reach a certain threshold? If so, what is that threshold temp?


  24. I am very impressed with MrCool’s new universal systems. I plan to purchase Mr. Cools 4 to 5 Ton 18 SEER Variable Speed MrCool Universal Central Heat Pump Split System – Upflow/Horizontal from Ingram’s. Before I make the purchase, I want to make sure I can convert the upflow to downflow in a similar fashion most use to convert a traditional air handler by Goodman, Rheem, etc.; by either reversing the coil or moving the drain pan to the opposite side. Please advise. Thanks.

    1. The default Universal air handler is not designed for downflow operation. However, the Universal condenser is non-communicating, so it could be paired with a downflow air handler.

  25. Is it possible you guys provide pictures SSOP’s to show the wiring steps for the condenser, air handler and thermostat?

      1. I would like the document too. I’m in the process of installing the universal 2-3 ton system and need to know if I run a separate thermostat wire from the thermostat to the condenser and the air handler. Thank you

        1. With regard to thermostat wiring, this unit is wired as most all other split systems in that the thermostat wire goes to the indoor unit, then on from there to the outdoor unit. The Universal system uses a heat active reversing valve (terminal B).

  26. How’s the zoning work on this unit. I’m planning five zones, all ducted and with motorized dampers and each with its own thermostat.

    Does the system come with a digital controller to tie in the 5 zones, and if not, can it be connected with a Honeywell or any other brand of digital controller?

    Last, is the compressor a modulating unit, meaning can I run just one or two units at a time?

    Thanks in advance for your input.

    1. The Universal heat pump is not intended for zoning and will most likely not perform very well when in zoning applications. There’s not really a way to to use different speeds in the air handler. Motorized dampers could work with this unit, but we can’t really advise beyond this point. The Universal is compatible with most third-party systems including Nest. The compressor uses a DC inverter to control the motor speed and continuously regulate the temperature output.

  27. Is there a 4 zone ceiling cassette system and if so is it DYI. I have one zone that has no exterior wall and I am wonder about drainage for a wall unit

  28. A traditional thermostat sends an ON/OFF signal to control cooling, heating and fan. How does MrCool Universal vary compressor motor speed based on this signal? Is it 100% or 0%?

    1. The Universal system condenser monitors line temperatures and pressures and ambient temperatures to govern the compressor operation.

  29. Can you connect a Mr Cool Universal condenser to a Mr Cool 95% AFUE gas furnace instead of the air handler?

    1. Not exactly, but you could have a MRCOOL Universal and a Signature Series 95% AFUE gas furnace on the same split system with an air handler. You would definitely need the air handler though, since a furnace does not have the coil necessary to exchange refrigerant with the condenser.

      1. How about the Universal condenser hooked up to a Mr Cool signature series Evaporator coil and a 95% AFUE signature series furnace instead of the universal air handler?

        1. The Universal condenser is a very flexible unit. It could potentially function in a split system with an Signature Series coil.

  30. I have an existing 16x25x4 filter cabinet. I would like to use MERV 13 filters. Is the air handler compatible with this filter type? What is the maximum total allowable pressure drop across this unit. Thanks.

    1. While there are other factors involved, generally the filter you describe would raise ESP for the system above the 0.4 recommended maximum.

  31. I recently purchased Mr. Cools 4 to 5 Ton 18 SEER Variable Speed Universal Central Heat Pump Split System – Upflow/Horizontal from Tim at Ingram’s Water (270-575-9595, ext. 121) who was very helpful in helping me decide on the best system, as well as accessories for this system.
    I am very pleased with this Mr. Cool Universal System! I installed this system myself, using the Mr. Cool quick connect (pre-charged) line set, saving at least $,1600 on installation fees, as quoted by a local HVAC contractor, and got an 18 seer unit for less than the 16 seer unit price as quoted by the HVAC contractor. The fan on the condenser is very quiet, and the variable speed allows the unit to be much more efficient than a standard condenser, not to mention the condenser looks sharp as well. The system blows ice cold and works very well considering the humidity and heat we experience during the summer months in south Mississippi.
    When compared to other 18 seer units, this one sells for almost half the price of what most typical 18 seer units sell for in the market place.
    If you are looking for an excellent heat pump split system to replace your current one with, you cannot beat the best in class quality, comfort and design this unit offers.

  32. Will the universal 5ton condenser work with the a 5 ton air handler system used with a trane 16xi in a 3200 sq ft house in pacific northwest

  33. Will the 5 ton universal condenser work with same 5 ton air handler used with a trane 5 ton 16xi in a 3200 square foot house in the pa ific northwest

  34. Will these units be ‘communicating’ units in the future? Is there any way to make a non-communicating unit into a communicating unit so that we can take advantage of ecobee and the likes?

    1. I’m sorry, but we have no plans for that at this time. We have no official guidance on how to convert a Universal into a communicating unit.

  35. Where can I get System Performance at Design Temp data for Manual S calcs? Specifically for the Mr Cool Universal series heat pumps and air handlers.

  36. I like the footprint of the Universal condenser, but want to pair it with one of your coil evaporators so that I can still use my existing gas furnace/blower. Can I do that and still be able to use the pre-charged option with quick connect lines? I am looking at a 3 ton setup with 50′ of line needed between condenser and evaporator coil.

  37. Could I install a hydronic heat exchanger in the Mr. Cool Universal air handler for backup heat instead of electric heat strips? If so, is there room to install the heat exchanger beneath the evaporator coil? I live in central Ontario, Canada and anticipate I would need the 5 ton system for a 3000sf home.

  38. Can the 4 ton condenser work on existing 40amp circuit? Or does it need to be rewired for 50amp circuit? I ask because my current 4 ton condenser; that needs to be replaced is using 40amp circuit. From my research it’s 5 ton units that need 50amps Thank you for your help in advance.

  39. My current system is a 4 ton 1995 high efficiency Trane system, everything matches up for a direct replacement except for the electrical. My condenser electrical hookup is 8 gauge solid copper with a 40 amp breaker. This meets the minimum amperage of 35 amps but confused if it meets the maximum 45 amperage? Does the electrical requirements change depending on 4ton or 5ton setting?

    1. Though the 2 and 3 ton models (in the same unit) are quite different, the 4 and 5 ton models (in the same unit) have the same MCA and MOP amp ratings.

      In the US, the NEC may only require the MCA (minimum circuit ampacity) as a standard (35 amps in this case), but other regulatory agencies (state, local, etc.) will go above and beyond this; thus, it’s industry standard to go with the MOP (maximum overcurrent protection) (45 amps in this case) when gauging your wire. This way, you know that your wire is sufficient all the way until the breaker trips.

      Our warranty requires MOP gauging and at 45 amps this would be 6 gauge wire.

    2. Wire size for an outdoor unit only needs to be sized to the minimum rating with a breaker sized for the maximum rating.

  40. Hi I have the mr cool diy 36000 btu I am wondering why .. I turn the heat mode on and set fan to auto 66 and it’s not heating do I shouldn’t have too keep it on turbo mode I don’t understand why it won’t keep it at 66

  41. Can you tell me the Brand Compressor that is installed in the 3 ton Inverter Heat Pump?
    I am comparing your product to the quality of Daikin and Compressor Manufacturers are being considered in my Decision.

  42. My understanding is that these units change from 2 ton to 3 ton by adjusting fan speed and refrigerant transfer speed between the outdoor coil and the indoor coil. Does that mean they are a 2 ton unit that works faster to output more btu or are they 3 ton units that slow down to not move as much air and refrigerant? In that same question how do they compare to the ability of a signature series 3 ton?

    1. A Universal on a 3 ton setting is similar to a Signature Series 3 ton or any other 3 ton system. The Universal can modulate capacity to meet demand.

  43. Since the system is non-communicating, how does the condenser modulate compressor speed? I understand that there are dip switches to change the maximum output between 2 and 3 tons. Is the condenser looking at pressure and temperature on the vapor line or some other data?

    1. The control board in the condenser is programmed to use the temperature and pressure sensors to regulate the compressor.

  44. On the 4/5 ton Universal Air handler it has two sets of dip switches labeled COOL (SA1) and HEAT (SA2) that set fan speed combined with operating as a 4 or 5 ton unit. Can I set the heat dip switch (SA2) to medium fan speed 4 ton, while also setting the cool dip switch (SA1) to low fan speed 4 ton?

    I am trying to achieve a lower fan speed for cooling to get rid of humidity while having a higher fan speed for heating for circulation. The instruction manual only shows the two switches in unison and leaves this vague.

  45. i have a mini split 36btu bosh 5000 series but is one problem after another with the condenser unit so i wonder if can i swap the condenser or not and how much will cost if i purchase your condenser unit

    1. The Universal condenser is non-communicating, so it can work with just about any air handler. As such, it should be possible to switch out your current condenser for a new Universal. You can find pricing for the Universal here:

  46. I’m looking to purchase a new furnace in my cabin in northern Minnesota where winter temps get down to -25 +. Is the mr cool universal going to keep it at 70° with out heat strips or a lp back up.

    1. The Universal does very well in extreme cold temperatures. We maintained a warm interior in a home in Grand Forks, North Dakota in similar temperatures in January 2020. That being said, we do recommend you have auxiliary heat strips installed as back up option. You should not need an LP or natural gas back up.

  47. Will the 4 ton universal work with zoning? We currently have an air handler that is dual stage and was wondering how the system would work since it is non communicating? Is the air handler variable speed ? Is the condenser targeting a set superheat?

    1. The Universal is not designed for zoning, but an installer could perhaps adapt it to an existing system. The air handler is single stage and can be set to any of the three available speeds. The controlling electronics do not concentrate on super heat- the board uses several sensors to determine operation of the compressor.

  48. Any update on a downflow unit? I have an old seer 13 unit on its last legs and I would love to replace it with a universal.

    1. I’m sorry, but we do not have an update at this time. However, the Universal is a non-communicating condenser, so it could work with a non-Universal downflow air handler.

  49. My universal unit that I just received does not match the specs on your web site.
    It’s the 2-3 ton system and the outdoor unit is
    MCA is 29
    MOP is 50
    This is more than is listed on the specs on your web site.

    Web site has MCA 24 and MOP 40
    What would be the cause of this?

  50. I have a 2 1/2 ton 13 seer air handler. Will the difference in seer rating between the Mr. Cool universal outdoor unit (18-20 seer) and my current 13 seer indoor unit effect the longevity of the Mr. Cool compressor? Also, what is the best setting on the Mr. Cool condenser unit to pair with my current 2 1/2 ton indoor unit, 2 or 3 ton mode?

    1. If the rest of the system is compatible (TXV, not contaminated with R22 refrigerant oil, etc), then it should not affect longevity. It will affect the overall efficiency (lower) and it would be best to use the 2 ton setting for the condenser.

  51. Regarding the 2-3 universal heat pump installation instructions. The guide states on page 18 that a 410 txv “bioflow” valve must be installed on the air handler. What is a “bioflow” txv valve. Is this a typo? Did the guide intend to say “biflow” instead of “bioflow.”

    1. Yes, that is a typo. The TXV must be a BI-FLOW- it must have a bypass to allow refrigerant to flow in either direction for heat pump applications.

      1. What defines “need”? Is it outdoor temperature or runtime or return temperature?
        Ideally the system (condenser) would output much less at 70F vs at the high and low temperature extremes.

  52. Hi,
    Is your
    MrCool Universal 2 & 3 Ton DIY Central AC & Heat Pump Split System with Precharged Quick Connect Lineset
    Runs on gas or it’s pure electrical?
    Thank you

  53. Using the Universal 5ton condenser and evaporator and using an existing line-set. Is there enough pre-charge so as not to have to add. The existing line-set is approximately 40ft

    1. The maximum pipe length that would require no additional charge is 31′. A 40′ line would need additional refrigerant.

  54. I have a 3 ton Unico high velocity system with a noisy 3 ton 2 stage Lennox outdoor unit I’d like to replace with a MR Cool. Not sure how well It would match.

    What is the target superheat of the internal EEV? Is it adjustable for a colder coil/low airflow. I can select any airflow for low stage. What is the minimum capacity of the inverter?

    1. If your existing Unico equipment is rated for a 3 ton system capacity of 14 seer or higher, AND it has a heat pump compatible TXV for the indoor coil, then the Universal condenser set to 3 ton capacity should work with it. There can be no AHRI certificate for the system however it would function. There is no “target superheat” for this condenser, and the EEV is not adjustable in any way. It is controlled solely by the electronics in the board. You would need to set the air flow for something near the 3 ton air flow requirement – the condenser operates from a single stage call and there is no minimum capacity- it will operate at the setting you choose, either 2 ton or 3 ton.

      1. So can in use different airflows for different stages? Nominal airflow is 250cfm/ton on the Unico. It has a oversized low approach 6 row coil with a colder coil temp by design for higher latent to sensible ration. It delivers approx 2.5tons total capacity at 750cfm. Can I operate it on low stage for example at 450cfm, which would deliver approx. 1.6tons total capacity?

        Also, if you had liquid line solenoids installed on the liquid line and used a simple zone panel, could you operate multiple indoor coils with a single Mr Cool outdoor unit?

        1. What you are describing is a rather dramatic deviation from the installation the unit was designed for. It may work with 250cfm per ton air flow, but it would not be an application we support. The standard in the industry is 400 cfm per ton with 20% less being acceptable. Anything less than that would be a non-standard installation. Connecting multiple coils to one condenser would also void the warranty.

  55. I plan to install this Universal condenser unit for my 2300 sqft, 2 story home in San Diego. so a 3 ton or 4 ton probably would be good. However, I would like to have the option of a gas furnace. What is the best approach for the indoor unit; using the default Universal indoor unit in combination with a gas furnace, or use a conventional indoor gas furnace plus a cooling module on top of it?

    1. For warranty purposes, it would probably be best to go with a Universal air handler.

      Though I would point out that if you’re in San Diego CA, you absolutely do not need a gas furnace. The Universal can keep heating at -20 degrees. If San Diego ever has -20 degree weather, then the whole planet has much bigger problems!

  56. I have two questions:
    (1) How does defrost work on the universal, if auxiliary heat in the air handler is optional?
    (2) With the unit monitoring pressures and temperatures and keeping demand and output closely matched, does that mean the unit would be therefore relatively immune to short-cycling, even if oversized, unlike traditional units?
    Thank you!

    1. The indoor will still communicate with the outdoor unit to ensure that the air leaving the indoor unit is not too cold during the defrost cycle. No system is immune to short cycling, so we would recommend installing the appropriate size in your space, but because of these reasons the Universal may be potentially resistant. Speaking to a technician at 270-366-0457 may better help you with your needs.

  57. my Hvac consultant says my home needs 28,600 sensible btu’s and 7076 latent Btu capacityon the hottest afternoon. house is 1900sqft which system do i need 2/3 ton or 4/5 ton? thanks

    1. Based on the numbers you provide the best selection of those you present would be the 2/3 ton Universal system set to the 3 ton capacity.

  58. Does the condensor come with a liquid line drier?
    I saw that the defrost cycle for the Mr.Cool only last 2-5 minutes. Is that accurate, or is that rare? What is the average defrost time in 0° degree temps?

  59. i need a system like the universal series due to outside space constraints for the condenser. i like the horizontal fan condenser so I can wall mount up high. is it possible to use this 3 ton system with your gas furnace?

    1. i forgot to mention that i only have a 100 amp electric service. my house is old. 1960 crawl space, 3 bed, 2 bath, 1152 sq ft. 8 foot ceilings, wood siding, fair insulation (for now)

  60. Hi I was curious does this unit have the compressor ramp up and down depending on the temperature call like a traditional ductless mini split or since it’s made to work without communications inside with the evaporator or the thermostat it acts more like a traditional split heat pump?

  61. How does defrost work on the universal outdoor unit?
    Is it exercising the reversing valve or using electric heat built into the coils?
    Thank you!



    1. That is a good question. It is something we’re exploring. We have no timeline on when it would be available. If we can bring a viable geothermal DC inverter to market, we will definitely do so.

  63. I am looking to replace a 2.5 ton Goodman, Heat Pump and air handler, for a condo, 1480 sq ft.
    Where to buy Mr Cool Universal Unit and air handler and who would install for me. I have looked on Angies list but Not satisfied, Lowes and Home Depot seem not willing. Help, I want a Mr Cool Universal installed in not to distant future. Love what I read on Mr Cool and Reviews.

  64. I am a long time HVAC contractor in California, I just purchased and installed a Mr. Cool 2/3 tom Heat pump in my vacation home , I am very pleased with it, it is SUPER quiet and the performance is outstanding. In addition I was very impressed with the quality of the unit itself, its very well built, all copper tube coils, heavy gauge metal cabinet and heavy duty internal components. I will recommend this unit to all my customers.

  65. I have a 2500sqft home with a gas central heater that’s as old as the home. Home was built in 1993. I just happen to see the Universal split you guys have. The question is how big of a unit do I need to heating and cooling? I have duct work in the attic and planning to tie into that duct work. I would like to put the air handler in the attic as well. What would be a good system for me? If I need some duct supplies to make the connection where can I buy that?

  66. is the universal condensor a single stage, 2 stage or variable stage unit. I’m trying to connect it to my goodman furnace and I’m not sure what connection option to use.

  67. Recently I saw that this outdoor unit can be paired with a universal A-coil so it can be used in a dual fuel system. I’d like to use it with precharged line sets but I can’t find part numbers, specs, or availability.

  68. We are looking for a combo system ~ My husband thinks he heard Mr. Cool offers a system that heats and cools with an option of dual-source, gas, and/or heat pump. Being located in central Minnesota we experience extremes in temperatures.
    Our air system failed and we have yet to replace it and our heater is getting old. We would like to replace both with a single Mr. Cool unit.

    1. You could combine the Universal condenser with a gas furnace to help maximize heating power. You can visit for more information on the Universal system, and you can give us a call at 270-366-0457 for more guidance on proceeding with a slightly atypical Universal installation.

  69. I purchased a 2-3 ton that blows amazing. My brother in-law purchased a 4-5 ton and it seemed to blow about the same or less. He only has five more vents, is the a blower fan seeing on the indoor unit?

    1. It could be working as normal. It’s hard to say without more information. You can call us at 270-366-0457.

  70. I am building a well insulated and air tight house with an ERV as well and I’m considering Mr Cool. 3 levels (including basement) for 6000sqft if finished basement sqft is added. I was wondering what size MrCool Universal would I need to adequately cool/heat it.

    1. For that great of a space, you would likely need multiple Universal units. You would roughly need over 10 tons to cover that amount of space overall, and the largest Universal we offer is 5 tons. Take a look at for more information regarding sizing.

  71. Is the blower in this unit downflow or upflow? I have a unit that is downflow, (crawlspace ducting) and would like to use this unit, if possible.

    1. The current Universal is not downflow. However, we will have a downflow option coming this summer.

      1. AC has died and needing replacement ASAP, do you have any indication of when the down flow version of MR COOL Universal will be available? Couple weeks / months? Can the current Universal air handler be modified for Down flow?

        Many Thanks

        1. New Universal products should be available through most dealers by the end of June. The current Universal condenser could be paired with a downflow air handler, since the condenser is non-communicating.

          1. Kinda need the downflow unit myself. Though if forced to it I might just fiddle with the ductwork to make an upflow system work properly. I have the space, just, do not like doing it that way, as it would add a lot of 90 degree bends to the air ducts.

  72. Hello Mr. Cool. Please help! I just finished installing the universal 3 ton split airhandler and condenser. It replaced an older 3 ton with already existing ductwork. There are no instructions on wiring the thermostat in any of the manuals. I have and ecobee and we have not been able to get the outdoor condenser to kick on. It is wired and has power. When we turn on cool the led reads on but nothing happens. I am a bit confused as the CO condenser has the low voltage communication spots including W, B, and C. So I have w going from the thermostat to airhandler to condenser and I have constant B going from thermostat also to air handler and then condenser and finally I have O orange going from thermostat to air handler and to condenser. And it’s not working. I’ve tried emailing support but I have no response. The idea of DIY is so I do not have to involve the hvac pros so I’m trying to avoid this.

  73. I have a mini-split ac system. The evaporator failed and I have a new evap. Problem is the condenser is 24vac to feed the evap however the evap is 24vdc. Can I make these 2 items work together ? I know the 230v will work between them but am concerned about the communication wire.
    Please help.

  74. I have a 3200 sq ft two story home in Manhattan Beach, CA. Temps here range from high 40s in winter to high 80s in the summer. I know you state that a 5 ton unit is designed for homes up to 2500 square feet, but would it also work for my home given the moderate temperature range?

    Also, have any customers had success using a MRCOOL Universal in a dual zone system? Would I need to buy a third party air handler?

    1. While it might be able to do that, you would likely benefit much more from two smaller systems rather than one large system. The Universal is not specifically designed for zoning, but you could do something similar with two units. If you would like, you can give us a call at 270-366-0457 so you can get the best advice from our tech support team.

  75. Is the thermostat split from thermostat , or jumped from air handler to condenser ? and is it five wire ?

  76. When can we expect the downflow model to be released? Saw late June in the prior comments, but I can’t find any retailers with a downflow air handler.

  77. I have a problem room for heating, currently use space heater to bump up the temperature. The room is about 300 sq ft and I am wondering if the 12000 btu would be a good choice for heating/cooling. I live in Minnesota so need something that can work in cold temperature. Thanks

  78. Does the MRCOOL Universal work with an air handler with an electronic expansion valve (EEV), or does it only work with a TXV valve?

  79. I have a 3 level house with 2600 sq. ft. This house was built in 2008. I have downflow duct work with the main duct from plenum has a size of 16 inches diameter(round flex). Currently this has Trane XB80 (80K BTU) furnace. Looking at the sq. ft. I bought the 120K BTU signature series furnace, 5 TON universal compressor 17 SEER and 5 TON downflow signature coil 16 SEER.

    A local HVAC installer said,

    1. My duct size is small for this big of a system and it will cause the furnace to fail.
    2. signature series coil with 16 SEER cannot be paired with 17 SEER condenser as it will freeze the coil.

    What should I do here? I do not see the universal A-coil with higher SEER ratings released yet.

    Should I go with 70K BTU furnace and a 3 TON system?

    1. The 16″ round duct is adequate for a 3 ton system but not a five ton, and it will cause the blower motor in the furnace to fail if used at high volume/ static pressure. The coil would be acceptable for use with a 5 ton condenser if it is installed with a TXV and the ductwork is adequate sized. It will not produce maximum efficiency, but it will work. You can discuss this with your installer, however it might be possible to operate the AC system on 4 ton capacity and still stay within reasonable static pressure levels with the blower set for the proper volume for 4 tons, and set the furnace for 1st stage only for heating capacity if needed.

  80. I recently installed a 2400 btu Mr. COOL with 2 12’s in my upstairs loft mother-in-law suite. I live in south Louisiana, is it normal for the drain hose to release over 2 gal of water in a few hours. The units are working great. They are set on 70°, I just want to make sure I’m not over working the units. One drains out on to my driveway but I can direct it away with a little more work and $ if this is normal

    1. South Louisiana is a high humidity environment, so a significant amount of condensate creation would not be unusual. It doesn’t sound like it is a problem.

  81. Can the Universal 2-3 Ton Air handler be configured for either Horizontal-Left or Horizontal-Right operation?

      1. Thanks– but to clarify, I don’t see any procedure in the manual for reconfiguring for horizontal-left vs. horizontal-right? Is it just moving the secondary drain pan to the opposite side?

  82. hello- I purchased the universal 2/3 tons package with 50′ lineset. I plan on installing the two units myself. I’m also planning on replacing the existing duct-work and plenums. A couple questions:
    – What’s the size of two plenums- Supply & return?
    – Are there any prefabricated ones that I can buy online or do I have to customize them?

    1. The physical sizes are: Supply- 11 5/8 D, 20 W; Return (base size) 21 1/4 X 21 1/4. HOWEVER, most areas have code requirements for ductwork size and types. Kentucky requires a minimum of 6 sq in per 1000 btu capacity. Therefore at the 3 ton setting the minimum cross sectional area for both the main supply as well as the main return would have to be 216 sq in. There are no prefabricated items that can be purchased. The adapters for both supply and return would need to be fabricated by a local sheet metal shop.

  83. Can you tell me what size the lineset is, for example, 1/4 inch and 3/4? And also can I use traditional lineset and not the precharged lineset.

      1. Please correct me if I am wrong but we need the heat pump primarily for heat. My understanding is the universal A Coil is cooling only.

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