Ductless Mini-Split Heat Pump Buying Guide

A ductless mini-split heat pump is a compact and versatile heating and air conditioning alternative to conventional HVAC systems reliant on ducts to distribute conditioned air throughout an environment. Ductless technology is ideal for applications in which installing a conventional product would be too costly or technically difficult to be worthwhile. Are you interested in mini-split technology, but don't know what you need to get for your home?
Don't worry, this buying guide can help.
Ductless Mini-Split Heat Pump Overview
Ductless split systems might be smaller than central heating and air units, but they're just as sophisticated. Let's start with the basics:
- Ductless units rely on the same refrigeration cycle as regular air conditioners.
- All ductless mini-splits are electric. None need natural gas or other fuels.
- Unlike window air conditioners, ductless mini-splits can be very energy efficient.
- Overall, ductless units need a much smaller installation footprint than central HVAC units.

Types of Ductless Split Systems
Ductless Split System Air Conditioner
A ductless split system air conditioner is the most basic ductless unit you can find. These are cooling-only systems. They typically feature an interior wall-mounted air handler and an outside condenser. These are lightweight, and easy for a trained professional to install. If you will only ever need cooling, a ductless a/c unit could be a great choice for your home.
Ductless Split System Heat Pump
Ductless split system heat pumps are typically the product we recommend to customers who want a total comfort ductless solution. Like a ductless air conditioner, a ductless heat pump can cool, but it can also heat. That flexibility is really valuable, and typically does not increase the sales price by a large margin. Generally, ductless heat pump heating is good for early spring, late fall, and mild winter conditions. They are not designed to heat at maximum capacity below freezing or below zero.
Ductless Hyper Heat Units
Many manufacturers sell ductless "Hyper Heat" units. These are ductless heat pumps made to optimize their cold weather heating potential. In this regard, the developers have been fairly successful in fielding a heat pump that can produce significant heat below freezing and even below zero. While a Hyper Heat ductless unit is no replacement for a traditional gas furnace in extreme cold weather regions, these are the most effective ductless heating tools available.
Ductless Multi-Zone Systems
A ductless multi-zone system is a ductless heat pump that connects multiple interior air handling units to a single outside condenser. Typically, a ductless system is installed to service a single interior zone. Multi-zone systems can provide heating and cooling for up to five different interior zones. That is often sufficient to distribute conditioned air throughout an entire home of average size.
Ductless Air Handler Configuration
While ductless condensers are all very similar in design, ductless interior air handlers are available in different shapes and sizes. The most common wall-mounted air handler is a lightweight rectangular box that hangs on an inside wall. Ceiling-mounted cassette units can be installed in ceiling spaces when desired or when wall mounting is not an option. Ceiling-mounted concealed duct units are another option for homeowners who do not find either wall-mounted air handlers or cassettes to their liking.

Common Ductless Components & Features
SEER
SEER stands for Seasonal Energy Efficiency Ratio. Long story short, SEER is a measure of how efficient your heat pump or air conditioner will cool your home through a long hot summer. Just like conventional products, ductless mini-split heat pumps measure their cooling efficiency with SEER.
HSPF
HSPF stands for Heating Season Performance Factor. Like SEER, HSPF is a measure of efficiency. Unlike SEER, HSPF measures winter heating performance as opposed to summer cooling. The better the HSPF, the more efficiently your ductless unit will heat.
Compressor
The compressor is the heart of any heat pump or air conditioner. That is as true for ductless units as it is a big central a/c. Previous generation systems tended to use rotary or scroll compressors. Many of the newest ductless units use inverter compressors. Inverter compressors are definitely a superior choice, and when possible you should opt for a ductless unit that relies on one. They allow the heat pump to operate more effectively and efficiently.
Blower Motor
A blower motor is an interior air handler component. Quite simply, it is the part that blows air over a hot or cold coil to make the interior zone either hotter or colder. It's really that simple.
Coil
The evaporator coil and condenser coil are two parts of the same device that allow a heat pump or air conditioner to cool, heat, or dehumidify. Most ductless coils are smaller than their conventional counterparts due to the compact size ductless applications require. Whenever possible, opt for a coil that is corrosion-resistant, since corrosion is always a major long term coil concern.
Wireless Capability
The vast majority of ductless mini-splits (or conventional HVAC systems) do not have any wireless or smartphone compatibility. However, this is changing. The latest generation of ductless products allow homeowners to control their ductless units with smartphone apps. Some top-of-the-line units are even compatible with common smarthome products like Alexa, Google Assist, Nest, and others.
Refrigerant Line Set Connection Type
The most common ductless lineset you will find are flared connections. Any experienced professional will find these easy to work with. The newest lineset on the market are precharged lines often sold as DIY products. These lines are precharged with refrigerant, and are usually only compatible with certain products.
Air Filters
Just like any central air conditioner, a ductless mini-split heat pump will have an air filter or filters that it uses to keep dust, pollen, and other contaminants away from the coil. Always refer to your owner's manual, but these usually need to be cleaned regularly. Which means every month or two, and not every year or two.
Warranty
Ductless mini-split heat pump warranty terms and conditions can vary, so be sure to read any warranty before you buy a product. However, most ductless units come standard with a warranty that will last anywhere from 5-10 years. Sometimes you may need to register the warranty to get the full terms. You typically have 60 days to do that from the date of installation. Don't forget!
Ductless Mini Split System Top Sellers

Want to Know More About A Ductless Mini-Split Heat Pump?
Do you still have questions about ductless mini-split heat pump or air conditioner systems? Just ask us in the comments below.
Can I heat and cool a 700SF apartment with this type system? what BTU & system would work best? How do I find an installer in my area? Portsmouth, VA 23707
You can potentially heat and cool any space with a ductless mini-split, but there may be some limitations. If you have a single zone, or only one interior air handler, then it will only be able to heat and cool any space open to it. In other words, if it is placed in a living room, it will not be able to heat and cool a bedroom if the door is shut. If this is not a concern, then depending on multiple factors like insulation, sun exposure, and the number of people normally in the space, either an 18K BTU system (typically covers ~750 square feet) or a 24k BTU system (typically covers ~1,000 square feet) might work. This being said, the only way to know exactly what size of system you need is to have an HVAC tech perform a Manual J load calculation on your space.
If I was going to install at 12,000 BTU mini split, does it matter if I get 120V or 240V? Is one more efficient, quieter, better, less costly to operate and/or maintain?
One is not necessarily more efficient or better running than the other. This is simply based off of your electrical requirements.
I live in DFW Texas area. I have a metal building with 2" closed cell foam, 1 rollup door, 2 windows. concrete floor . I'm curious about what ductless mini split size I should be looking at for heat and ac
It depends on your space's square footage. A 12k BTU system might be a good fit for a 500 square foot space, an 18k would cover around 750 square feet, 24k could handle 1,000 square feet, and a 36k could work well for around 1,500 square feet. Multiple factors can affect this, though, such as climate, insulation, and sun exposure.
What is the difference between 4 gen and easy pro series?
The Easy Pro is essentially an economy version of the 4th Gen DIY Ductless Mini-Split. While you can install the Easy Pro yourself like you can install the DIY yourself, it has a lower price point, lower efficiency, and a shorter warranty. There are pros and cons to the system, allowing you to make the best choice for yourself.
How do I calculate the size mini-split that I need. This unit will be for a garage that is 27x44x12.
An HVAC professional performing a Manual J load calculation is the best way to ensure you know what BTU capacity you need, because it takes multiple factors like insulation, sun exposure, and a number of other variables to come up with a precise number for what you need. For an estimate, which won't take multiple factors that do affect the size you need into account, a 36k might do the trick for this space, but once again, this doesn't take affecting factors into account.
Do any multi-zone ductless mini-splits, VRF or non-VRF, simultaneously heat and cool? I can't find anything on the Internet about separate zones running cool and heat at the same time.
Since all of a multi-zone mini-split system's air handlers are connected to the same condenser, nearly all multi-zone systems will have to cool OR heat at the same time. Heating and cooling at the same time on the same system is a goal for HVAC, though, and some companies seem to be developing tech to do this, but it may be a while, and it will likely be much more costly.
Hi! I am renovating a detached garage. R15 walls, R38 ceiling, insulated overhead door, 5 double pane new windows, 420 sq ft. I am in climate zone 5. I am primarily interested in using MrCool DIY heat pump but don’t really know which BTU rating I should pick. I will have auxilliary heat for when it is really cold ( less the 10 degrees) outside. Can you suggest a BTU rating for me?
For that space, we might recommend a 12k BTU DIY Ductless Mini-Split, which can typically handle spaces up to 500 square feet.
I have a new pole barn with a 36x60 main shop area with 12' ceiling and an additional 10x30 room with 9' ceiling on the side. The walls are insulated with R-19 and the ceilings are R-30. I was looking at a MrCool DIY 48K BTU unit with 3 12K wall units for the main shop and a 9K for the smaller room. Would this system be adequate for my situation or is there something else you would recommend? I am located in Tennessee.
It seems that the main shop space might be too large for three 12k air handlers. You might want to go with two larger systems, like a 24k and a 36k system depending on a variety of different factors. To cover the secondary room, the 36k could instead be a 48k condenser with a 36k air handler in the shop and a 9k air handler in the secondary room. Ultimately, it is up to you and what works best for your needs.
Need to heat/cool 660 sq ft metal building, steel frame, with 1" foam board insulation, and concrete floors.
1) What diy product would be recommended?
2) Can the indoor air handlers be ceiling mounted?
3) Do these plug in or are they hard wired?
4) Do they run on 110 or 220?
We might suggest the 18k BTU DIY ductless mini-split, depending on the climate you're in. The wall-mounted air handlers cannot be mounted to the ceiling, but MRCOOL recently announced a DIY ceiling cassette as an addition to their DIY series. It is not available at IWAE yet, but it will be available soon. These systems are hard wired. The 18k runs on 220V.
I am looking at the Mr Cool 24,000 btu diy. It is for a 950 sq ft well insulated garage. There is already a 20 amp 230 vac circuit run to an outdoor disconnect. I am seeing conflicting information between the 3rd and 4th gen units. What if the difference between the units and will they work on the existing electrical circuit?
The unit is more efficient, and comes with a DIYPRO cable, which eliminates the need for electrical conduit and protects the electrical lines. This system is also entitled to a limited lifetime compressor warranty, a 7 year unit replacement warranty, and a 5 year parts warranty if the customer registers their unit and signs up for the MRCOOL Care Kit program. The 4th Gen's max overcurrent protection is 35A.
Hello. I have a open 36X60 garage with 16 ft ceiling (2,040 square ft). What size do you recommend for that?
Depending on what you want, we might recommend more than one single-zone unit, or a 48k BTU multi-zone system. If you were to go with a single-zone system, we might recommend two 36k BTU systems, especially if the space isn't insulated all too well, or if you live in a climate that tends to have more extreme temperatures.
How long is the lineset
It really depends on the system you get. Some come with a 16' line set, others come with a 25' line set, others may not come with a line set at all.
I have a condo in Maui. Not well insulated. It has concrete walls. I am looking to cool the living room 300 sq feet and bedroom 200 sq ft with no windows. What do you recommend? Thanks
We might recommend a multi-zone system that has a 12k BTU air handler for the 300 square foot space and a 9k air handler for the 200 square foot space.
I am building a 720 sq ft guest house with one bedroom, bathroom, and living room with kitchen area. I am thinking of buying MrCool two zone 18k unit with a 9k and 12k. Is this the correct unit or would you suggest something else.
Sizing greatly depends on climate, insulation quality, sun exposure, and a number of other factors. If you have good insulation and live in a slightly more temperate climate, it seems as though this system could work well for your space.
I am building a 720 sq ft guest house with a bathroom, bedroom, and open concept kitchen and living room. I am thinking of getting a MrCool Dual Zone 18k heat pump unit. The two zones would be the bedroom 9k, and the kitchen/living room 12k. does that sound about right or would you suggest something else?
This could work, but the air handler sizes may depend on the size of the spaces you want to heat and cool with them. A 9k air handler typically heats and cools around 350 square feet, and a 12k air handler normally covers around 500 square feet.
I have a 30 x 40 pole barn. It has R-19 wall insulation and right now it has R-19 ceiling insulation. So this is one room that is 1200 sf. With 12 foot ceiling. Will a Mr Cool single zone 36000 btu be enough. This building has one insulated 16x8 overhead door. And 3 windows. And one man door. This building is just 2 years old so everything is very well sealed yet.
It seems like a 36k BTU DIY ductless mini-split could do the job, but if you wanted a little extra BTU power, you could get two systems like an 18k and a 24k, which can each handle around 750 square feet and 1,000 square feet respectively.
I forgot to add that we have lots of windows. Thanks!
Hi Kyle, We have a two story house on the Olympic Peninsula in Washington. (Similar weather to Seattle) The upstairs spaces we want to heat/cool are 360 sq ft and 462 sq ft with cathedral ceilings that are 16 feet. The downstairs rooms are 305 sq ft and 576 sq ft with 11 foot ceilings. We want to split them up so that one condenser handles the upstairs 462 sq ft space and the downstairs 576 sq ft space and the other condenser will handle the upstairs 360 sq ft and the downstairs 305 sq ft. Can you recommend sizes for us? Thank you in advance!
We might recommend a DIY dual-zone system with two 12k BTU systems for the two 300~ square foot spaces, and another DIY dual-zone system with an 18k air handler for the 576 square foot space and a 12k air handler for the 462 square foot space. You'll be able to find configurations for both these applications at https://iwae.com/shop/heating-air-conditioning/full-systems/ductless-split-systems/?manufacturer=173!
Suggestions on system (heating and air) for older farmhouse (built in two parts, 1859 and 1929). It is insulated but the newer side is 3 story, would need system(s) on 1st & 2nd stories only. Rooms that would need heat and cooling are 19 x 20 each with hallway on each floor, so hallway would either need heat/air to flow out to that area, or a unit specific to hallway(s). Upper hallway has propane stove between rooms but does not heat enough when very cold and 1st story rooms (except hallway) have propane stoves. Would this type of system work in a house of this age and size? What type of system and estimated cost? Is this something that a certified HVAC individual would need to install?
A ductless mini-split system works well in old houses, because they don't usually have ductwork, and it is hard to install. Cost depends on the specific system you get. If you just want one space heated and cooled, you'd likely get a single-zone unit, which, depending on the size, can be cheaper than a multi-zone unit. However, a multi-zone unit can provide great versatility when it comes to heating and cooling, because it means that you only have to install one condenser for up to five air handlers. You don't necessarily need an HVAC professional to install a ductless mini-split system for you either! MRCOOL has some great DIY ductless mini-splits. Take a look at their units here: https://iwae.com/shop/heating-air-conditioning/full-systems/ductless-split-systems/?manufacturer=173.
I have two bedrooms side by side on the front side of my home. They are both 204 square feet each, total 408 square feet. What size DIY min-spit would be best? I read something about having to use at least 2/3’s of the units capacity for it to run correctly? I would like to use a 2 zone system. Eastern North Carolina.
Depending on sun exposure, insulation, and a number of other factors, we might recommend a 9k air handler for each room. The MRCOOL DIY 4th Gen has a system that can accommodate this.
We need to cool a c .1877 2 story, uninsulated summer cottage. About 450 sq ‘ (not including the kitchen , bathroom extensions.). It is just balloon framed simplicity, open joists and rafters, barn-type sliding windows on sides. Ceilings were put up but I’d like them down someday and have fans hung from the rafters- ceilings much too low for them now in the bedrooms but use them on the first floor.
Downstairs open, enclosed steep stairway to upper level. Three small bedrooms open to the narrow hall.
The neighboring cottages are no more than 22” away on either side but there is a small back yard and a open side area beside the kitchen extension.
I think the heat can generally be tolerated by using blinds, fans and attitude but am alone in this and most family and visitors insist on cooled air. Allergies. Zoned split ductless system seems our answer - please comment. Maybe the heater would be good to have too , is it worth it for minimal total usage?
Because of use patterns, I am wondering if a unit for LR and DR, one for upper hall to serve two rooms and one for the larger bedroom that is often the only one used. Could they really be set individually? Could they be set to a reason temp so renters don’t ice it down all day long while they are away at Cedar Point?
What if the old joists are different from 24”oc? I don’t recall now, they may be more, may be less.
We might recommend a multi-zone DIY ductless mini-split system, if you would like to put air handlers in the bedrooms. These units can support up to four air handlers, although since the cottage is so small, you may not need all of the air handlers. If you do not want to put air handlers in the bedroom, you may be able to get by with a single-zone. The smallest DIY single-zone system, a 12k BTU unit, is able to cool and heat around 500 square feet. However, since you said this space is not insulated, you may want to go with a larger system, as this can affect the size you need. The mini-split can be controlled via a phone app for off-site control. If you would like, you could even remove the physical remote control that comes with the unit. If you'd like, you can also give us a call at 270-575-9595 so that we can assist you in choosing the best system for your needs.
I have a 1500 sq ft home in Missouri, single level 3 bedrooms ,2 bathrooms, it is a longer home and I don't believe I can get away with 1 condenser as it is farther than 25ft. i want heat and ac. what would be the best?
If you have ductwork, you might be interested in the Universal central heat pump split system. This is an extremely efficient system with an impressive range of operable temperatures. It must be connected to ductwork. If you're more interested in a mini-split, then you might want a multi-zone system. MrCool's DIY ductless mini-split can be installed without any HVAC professional's help, and you can link line sets together so that your line set is longer than just 25 feet by using Quick Connect couplers. You likely wouldn't want to install any air handlers in bathrooms, because they are high humidity areas, and that might negatively affect the operation of the system over time. The specific system that you get depends on the square footage of each space you want to heat and cool.
I'm building a 28'x30' cabin in central WV. Half of the cabin will be lofted with a bedroom and bath on each level. The remaining half is open to cathedral ceiling. I'm thinking that the Mr. Cool multizone with 9k units in each bedroom and an 18k unit in the main living area would be sufficient. What do you think?
It depends on the square footage of each of the areas. A 9k unit will be able to handle spaces under 500 square feet, and an 18k BTU air handler can cool and heat 750 square feet. The 27k BTU DIY mini-split condenser is able to support up to 3 air handlers, and the 36k is able to support up to 4 condensers.
How does the inside unit drain condensation from itself when using AC in the summertime
The air handler has a drain line attached to it that typically gets routed outside alongside the line set bundle.
Which is the appropriate DIY unit for a small, 250-square-foot studio apartment above a garage? Heating is more important than cooling, and it can get quite cold up here (Vermont). We are handy, and would like to install it ourselves.
A 12k BTU MrCool ductless mini-split might work for you. This size typically covers spaces around and under 500 square feet, but the extra BTU capacity can come in handy for heating. The DIY, however, won't be able to heat in temperatures lower than 5° Fahrenheit.
I have a 50’x50’ shop with 15’ ceiling, r49 insulation in the ceiling and r30 in the walls. Do you have a system that would work for me? I’m in eastern Wa.
The largest ductless mini-split system that we offer is a 48k BTU multi-zone Olympus ductless mini-split system, which is able to cover around 2,000 to 2,400 square feet depending on multiple factors, and would need to be installed by an HVAC professional. For that large of a space, we might recommend instead installing two DIY ductless mini-splits, like a 24k and a 36k.
Can you route the refrigerant line through the bottom center of a 24000 btu mini split. I would need to surface mount and cover with pvc ductwork.
Technically, that would be possible. We would recommend extreme caution when bending the line.
Do you know of any ceiling cassette mini-split options compatible with wood framed ceilings with 24" on center spacing? I've found Daikin and Fujitsu options that are slightly too large... We hope to avoid a larger carpentry project.
I'm sorry, but I don't. The units we have available are larger than 24 OC spacing will accommodate.
I'm looking at adding a mini split for our den (14' x 20' with 10' ceiling). The best wall for the indoor unit would be over our TV (toward the back of the house), which, I believe, is an issue because the unit would be blowing on the TV. The other three walls are the front, which is mostly windows, an interior wall and a wall to the attached the garage. I was wondering the best solution would be for an air handler. Our home is a ranch style house in New York (central Long Island).
Yes, it would be best to keep an interior air handler away from a TV. In terms of where else to put the unit, remember that it is possible to route the lines up and out through an attic. That would require a condensate pump for the condensate drain hose, but it's definitely an option. That might make an interior wall installation more viable.
Hello I live in southeast Tennessee looking at the Mr Cool mini split system , I live in a 1997 double wide with cedar siding , we have since added house wrap , plus foam board insulation , and vinyl siding. On the inside we have added D log siding over the existing Sheetrock- the home is 1900 square ft under roof - great room is cathedral type ceiling 10’ in middle approx 14 x26 - lg master bedroom 10x26 thinking I need a four zone - what would you recommend - definitely wanting the heat and air
A 4-zone could definitely work. You would likely want the 36k multi-zone condenser. Give us a call at 270-575-9595, and we can help you put together the system that will work right for you.
We are redoing our approx. 800 sf cabin in eastern, NE. Summers can get HOT, and winters can easily get below zero. There are 2 small bedrooms, like 100 sf each, and the rest of the space is living area / kitchen. Currently, each bedroom has a window unit and baseboard heating, but those are going away. What would be best to cool each bedroom and the main living area. Would the bedrooms each need their own unit, or could they possible share one, since they are so small? Also, does it matter where the interior unit is placed for the main room? The area is a rectangle - should it be centered on the long side, or on the short side, blowing the length of the area? Any insight into what type of system to get would be extremely helpful! Thanks so much.
I would recommend a single mini-split that can blow air throughout the length of the cabin. Given the information provided, you probably want an 18k unit.
Heat and air in 3 separate 480sf zones, I live in eastern WV. what would you recommend. Thanks
An Olympus or DIY multi-zone. Depending on your winter weather, you could do multiple single-zone Olympus Hyper Heat units.
building a two story home, 1384 sq ft lower, 1450 sg ft upper. want ot install two multi zone units. what size will be needed?
You would probably want between 24k and 36k BTUs on each level depending on climate and insulation.
I want to buy a 12000 btu and run it on solar/batteries. Do you have info on how many amp draw on low , med, high ? So I can figure out if I have enough amp hours to run it and for how long. Thank you
We could be able to get that for specific equipment. Give us a call at 270-575-9595.
I live in the Dallas/Ft Worth area, I have a 10 X 16 building that is insulated with closed-cell spray foam. I will use it as an office and want to heat and cool it. The building currently has 110 V run to it, I was considering a 110V, 9K BTU split system to heat and cool the building. In your opinion, would the 9K Split system do the job in the hot summers we have here in Dallas/Ft Worth, or is this too large for the area to heat and cool?
In general, a space that size would not be considered too large for a 9k.
I have an insulated room above my garage. It measures 19' x 19' with 8' ceilings. I live in MD. I am more interested in heating in the winter. (feb 20deg) although I do like the cooling in the summer. (aug high 90's). I looking at the 18k DIY. Is this overkill? Would a 12K BTU work, or would the unit be struggling?
For heating in Maryland in a space that size, an 18k would probably not be overkill.
Our cabin is located in Michigan's northern lower peninsula, the cabin is only 600 square feet well insulated. We rarely would go up in the winter. Our hope is to extend the fall and early spring seasons. Any suggestions?
A Hyper Heat mini-split.
I’m looking for a system to heat and cool a 900sq foot shop with 10 ft ceiling. I love in southwest middle Tennessee. What unit (byu’s) would you suggest?
You likely need at least 18k BTUs for air conditioning. You might need more depending on insulation and other factors. The only way to really know for sure is with a Manual J load calculation.
what size disconnect whip conduit is needed, 1/2" or 3/4" for a 12k single zone 115 volt mini split outdoor unit?
For the MRCOOL DIY 12k 120v, we recommend a 1/2". This one: https://iwae.com/shop/1-2-x-6-ft-non-metallic-electrical-whip-with-10-wire-ha12023.html
I have a detached steel garage. S.F. is 720. Ceiling is 12 feet. Will a 18K unit heat/cool. I'm not looking for house comfort, just decent temp in which to work and play.
There are a lot of factors at work in determining the right load for a particular space. In your situation it would come down to local climate. If you live somewhere particularly hot, I'd go with a 24k. If you have more mild weather, an 18k could be enough.
I’m in San Diego Ca - 10
miles inland. I’d like to put a 110 split in a 8x20 conventional framed tiny home. It has a 13 foot high open ceiling with an 8x7 loft. What size unit would you recommend? Minimal heating but maximum cooling needs. There is also very little wall space- is ceiling mount for the interior unit possible?
For a space that small, a 9k ductless heat pump could be sufficient. You would need to have a Manual J done to know exactly the right load. But you could start looking at units like this Mitsubishi with a ceiling cassette: https://iwae.com/shop/9k-btu-19-5-seer-mitsubishi-m-series-ductless-heat-pump-split-system-ceiling-cassette-ha18517.html
I have. 671 sq ft basement beneath a garage in kansas city mo. Concrete walls and 8 ft or less concrete ceiling. I'm looking at mr cool diy 12k or 18k. Which size would you recommend for both heat and cooling?
The only way to know for sure what you need is with a Manual J load calculation. An 18k would generally be considered the right choice for a space that size. The fact that it is underground, and therefore likely more stable in terms of temperature change, could reduce your requirements.
I live in northern California in a redwood forest, so the AC would only be needed a handful of times in the summer, heating needed most of the winter to replace a single wall furnace that is used to heat the whole house. The house is roughly 700 sq.ft total.
I tried to calculated my total required BTU's for our small house to be 9000 BTU for cooling and 14.100 BTU for heating, though I'm not 100% sure. The two bedrooms are small, 195 sq.ft and 150 sq.ft, but with high sloped ceilings. The sloped ceiling are 8.5' at lowest to 12' at highest point. The downstairs is all open plan (no doors except for the bathroom), roughly 352 sq.ft, with 9' ceilings.
The smallest Mr Cool DIY multi zone compressor unit is 27,000 BTU, and the smallest indoor air handler is 9000 BTU.
Will a 9000 BTU air handler and a 27,000 BTU outdoor unit in such small bedrooms be crazy/inefficient?
I am thinking of installing 27,000 BTU multi zone DIY outdoor unit, with two 9000 BTU air handlers for the bedrooms and one 12,000 BTU air handler for the downstairs.
Any feedback would be great!
We're not an engineering firm, so I can't say definitely, but what you suggest does not seem unreasonable given that mini-split systems use variable speed compressors that can operate at less than maximum load. It's a guess, of course, but it sounds right.
Also a tech question. Does the outside condenser need to be installed lower than interior air handling unit for any flow or gravity reasons? Im considering installing the outside unit higher for security reasons
An outside condenser can be installed higher than the interior air handler. The condensate drain from the air handler would need to be run down to allow for gravity removal of condensate.
Im renovating a house in NW Alabama. Very damp. I have a couple of questions. How well does the mrcool diy heat pump minisplit remove moisture from the air in heat and or cool mode? Second question since im renovating myself and going relatively slowly is it practical to buy a 4 zone unit and add air handlers to it as i finish off rooms or do i have to buy 4 handlers with a 4 zone unit
The DIY will dehumidify in cooling mode. It also has Dry Mode that will improve dehumidification ability. A multi-zone unit can be installed piece by piece. However, the initial installation must account for at least 50% of capacity.
What is the advantages between the DIY and ANVANTAGE units? Also looking at DuctlessAir units if you care to comment.
The DIY has pre-charged lines and simple connections. It doesn't have to be vacuumed or charged in the field. The Advantage units are not pre-charged, but they have a lower price tag. I'm not terribly familiar with DuctlessAir units, but the last time I looked at them they had very basic warranty coverage (only 1 year). The DIY is 5-year parts, 7-year compressor.
Have a two level, two zone structure. 1st level = 600SF, 2nd level = 700Sf. Need best rated, best priced Dual Zone DIY Heat Pump. Thank you
We'll have a member of our team reach out to you soon with some options.
Hi, Building detached garage workspace in middleTN; 2 stry 1200sq ft/level one big room each level 2x6 studs and closed cell foam. manual J calcs from software come up with 14k cooling 36k heating which i find a little odd because its freaking hot down here. looking to DIY w heat pump. With a heat pump, how do you consider the disparity in heating/cooling BTU? second, its one big room on each fllor but kinda long, was thinking about 2 air handlers per floor. Can you advice
It is not too unusual to see a significant disparity between the BTU requirements for heating vs cooling. When a heat pump is being used then normally there must be some additional source of heat if the unit is properly sized for cooling. If the system is sized for heating then there will be complications for AC operations. In general a large room will be better conditioned with multiple air handlers with the increased circulation.
Do these DIY kits come with everything you need? Or do you have other parts you need to buy, and if so what are they? I am looking at your 27K BTU 22SEEp Multi Zone MrCool DIY 3 Zone Ductless heat Pump Split system 9K, 12K, 12K. I am looking for it to heat three bedrooms that are each about 15x12
They come with most of what you need. They don't include a base pad or bracket for the condenser, disconnect box, or electrical whip. You also might need additional refrigerant lines depending on your installation requirements.
Can you shut off zones in a ductless Multi-Zone System when the rooms aren't in use? Are there time of day schedule controllers for each zone?
Yes, you can shut off individual zones. You can also set zones at different temperatures. Whether or not zone schedule control is available would depend on the features of the particular model.