Best DIY Mini Split Heat Pump Heating in 2026: 12,000 BTU Cold Climate DIY Install Guide

Heating a single room or zone in a cold climate with a 12,000 BTU DIY mini split heat pump, without tearing into your walls for ductwork, is a solved problem in 2026. The right system is one rated for sub-zero operation, and the best one available today is from Zone Air.

Answer First: Best 12,000 BTU DIY Mini Split Heat Pump for Cold Climates in 2026

The Zone Air 12,000 BTU 230V cold climate wall-mounted mini split is the best DIY mini split for heating-focused installs in 2026. It is built for cold-weather performance, with a heating floor of −13°F, an HSPF2 of 10.0, and a SEER2 of 24.0.

This unit wins for cold climates because of how it is set up and what you get in the box.

• Cold climate performance down to −13°F outdoor temperature, so it covers most northern U.S. and Canadian-border winters, where design temps rarely dip below that floor.
• It has an HSPF2 of 10.0, which puts it among the most energy efficient 12k DIY models on the market for heating-dominant climates.
• A pre-charged quick connect line set comes in the box, and Zone Air will cut a pre-charged line set to the exact length you measure, any whole foot from 5 to 75 ft. You do not need a vacuum pump, you do not need a refrigerant license, and you do not need EPA Section 608 certification.
• 5-year parts / 7-year compressor warranty with no registration deadline, and installing it yourself does not void it. Several flare-connection brands, Senville among them, tie their warranty to a licensed installer.

This guide focuses on single zone 12,000 BTU DIY mini split systems that are set up to put heating first and cooling second, in cold climates and the seasons on either side of winter.

For context, a professionally installed Mitsubishi Hyper Heat is built for even colder weather, but it needs a licensed HVAC contractor, it costs $5,000 to $10,000 installed. It's not a DIY option. Zone Air delivers strong cold climate performance at a fraction of that cost. You can do the install yourself in a weekend if you are a handy homeowner.

Quick Picks for Best DIY Mini Splits for 12,000 BTU Heating Use Cases

If you want an answer before the deep dive, here are the concrete picks for 2026. All are 12,000 BTU or close to it, and each serves a specific use case.

Best overall cold climate DIY 12k BTU: Zone Air 12k 230V. It heats to −13°F, with HSPF2 10.0 and SEER2 24.0. The line set is pre-charged, and you get a 5/7 warranty with DIY install allowed. $2,199.99 in November 2026. Zone Air rates it for roughly 400 to 600 square feet, though in a cold climate you should plan toward the low end of that range.

Best plug-and-play 115V DIY mini split: Zone Air 12k 115V. It's got SEER2 23.0 and HSPF2 10.0, the same −13°F heating floor as the 230V model, and it runs on a dedicated 15A circuit. With the optional 3-prong power cord kit it plugs into a dedicated GFCI outlet where local electrical code allows a plug-in install (never an extension cord). It was $1,999.99 in November 2026. This one is good for a small apartment or room where 230V wiring is impractical.

Best widely available retail DIY alternative: MRCOOL DIY 5th Gen 12k. The 12K 5th Gen is a 115V hardwired unit with 23.5 SEER2 and 10.2 HSPF2. MRCOOL's Easy Pro heats to 5°F. MRCOOL's standard DIY 5th Gen is rated to about −13°F, and higher-tier DIY models are rated lower. It's got pre-charged quick-connect lines, and it was around $2,359 at Home Depot when last checked in September 2026. The tradeoffs vs Zone Air are lower SEER2 than Zone Air's 230V model in cooling (23.5 vs 24), but its 12K wall head dips to about 18 dB against Zone Air's 30 dB. It's a solid choice among the best diy mini splits if noise in a small bedroom is the top priority.

Best budget DIY-adjacent 12k for cold climates: Senville Aura 12k. It's got strong cold climate output at 5°F and retains ~96% of rated capacity in some configurations, but it requires a vacuum pump and flare connections. This is a half-DIY approach, and the warranty may require a licensed installer. It's one of the budget brands worth considering if you have HVAC tools and experience.

Best off-grid / solar focused 12k DIY: Airspool HS12. The Airspool HS12 mini-split is rated to −22°F for cold climates. It's got direct DC solar input and EVI technology for sub-zero heating. This is a niche pick for off-grid cabins or homesteads.

Zone Air is the best diy choice for most homeowners who want reliable cold climate heating with the fewest install headaches. A 12,000 BTU unit typically heats spaces up to 500 to 550 square feet, though actual coverage depends on insulation and how severe your winters get.

What Is a DIY Mini Split Heat Pump?

A ductless mini split system has one outdoor unit (the condenser) and an indoor air handler. A refrigerant line set, a control cable and a condensate drain connect the two together. You don't need any ductwork. Mini-splits can go from 9,000 to 24,000 BTU, and 12,000 BTU is the size you'll see most often for single-room DIY projects.

Here are the key parts of a ductless mini split:

• Outdoor condenser: this is where the compressor and outdoor coil are. It sits on a concrete pad or on a wall bracket.
• Indoor unit (air handler): this is the part that goes high on an interior wall and sends heated or cooled air into the room.
• Line set: these are insulated copper refrigerant lines. They run through a hole in the wall to connect the indoor and outdoor units.
• Condensate drain: this is the part that takes moisture from the indoor head to the outside or to a drain.
• Control cable: this is the low-voltage wire that runs between the two units to connect them.

Heat pumps transfer heat from outdoor air into your home, even when it is cold outside. This is the opposite of electric resistance heating (baseboard, space heaters), which generates heat by running electricity through a wire. A heat pump moves 2 to 4 times more energy than it consumes, which is why it can cut heating bills so much compared to resistance heat.

The difference between DIY models and conventional mini splits is that true DIY systems use pre-charged quick-connect lines. With conventional mini splits, you need a vacuum pump, gauges, refrigerant charging and usually a licensed technician. With true DIY systems, you connect the fittings, tighten them and the refrigerant is already sealed inside. This means you don't need specialized HVAC certification for the installation.

A 12,000 BTU single zone system is the right size for bedrooms, offices, bonus rooms, a small apartment or a heavily used living space where you want independent temperature control.

Why Zone Air Is the Top DIY Mini Split in 2026

With cold weather ratings, efficiency and homeowner-friendly installation all in one package without cutting corners on any of them, Zone Air is the best diy mini split for 2026.

• Cold climate performance: The 12k unit heats down to −13°F, which is enough to cover the vast majority of winter nights in states like Minnesota, Wisconsin, Maine and New York. When outdoor temperatures are low, the unit's variable-speed DC inverter compressor changes its output rather than cycling on and off, so it keeps you comfortable. It is also rated to cool in outdoor temperatures up to 131°F, where MRCOOL publishes 122°F.
• Efficiency ratings: SEER2 is 24.0 for cooling and HSPF2 is 10.0 for heating. At 24 SEER2 on 230V, Zone Air has the highest efficiency of any pre-charged quick-connect DIY system from the brands we compared here (MRCOOL's best single-zone is 23.6). HSPF2 is the number that matters most in heating mode, and Zone Air's 10.0 is better than most budget brands while sitting within 0.2 points of MRCOOL's 10.2. That gap is so small that it only adds up to single-digit dollar differences on your annual heating bill.
• DIY installation design: The kit ships with a pre-charged line set and quick-connect fittings. You don't need brazing, evacuation or gauges. Of the brands compared here, Zone Air is the only one that'll cut your pre-charged line set to the exact length you measure, any whole foot from 5 to 75, as of November 2026. MRCOOL ships fixed 11.5, 16, 25, 35 and 50 ft sets plus couplers and has you coil the excess. Zone Air provides a written DIY manual, an install video library and install guides written for homeowners, not HVAC technicians. Easy installation is what they designed it for.
• Warranty and support: You get 5-year parts, 7-year compressor, with no registration deadline and DIY installation does not void it. Senville says DIY installation will void its warranty, and Pioneer's longer coverage depends on registering within a week of install. MRCOOL's DIY 5th Gen has the same 5/7 term with no registration required. You can get live technical support from 8 AM to 6 PM MT.
• Zone Air vs competitors: Compared to MRCOOL DIY, Zone Air offers higher cooling SEER2 on its 230V model (24.0 vs 23.5) and a 230V 12K option, which MRCOOL's standard 5th Gen line does not offer at 12,000 BTU. MRCOOL's indoor unit runs quieter at its lowest fan setting (18 dB vs 30 dB), so it's nice to have in a small bedroom. Budget brands like Pioneer or Senville often need a vacuum pump and professional charge. That adds complexity. Zone Air hits the sweet spot: it's cold climate capable, efficient and genuinely DIY.

How to Size a 12,000 BTU Mini Split for Heating

Many buyers go with 12,000 BTU because it's the most popular single zone size. That guess is usually correct, but you still need to verify it against your space.

• Square footage guidelines for a 12,000 BTU unit in heating mode: A 12,000 BTU unit covers 350 to 550 square feet. In well-insulated, tight homes with modern insulation, double or triple pane windows and little air leakage, plan for 400 to 600 sq ft. In older or poorly insulated homes in cold climates, limit coverage to 250 to 400 sq ft.
• Adjust for variables: ceiling height above 8 feet increases the volume of air that you need to heat. Large window areas and high air leakage raise the amount of heat that the space needs. Your local winter design temperature matters. A home designed for −10°F lows needs more capacity per square foot than a home designed for +15°F.
• Use a Manual J calculator to get the right size for your mini split. Zone Air's free mini split sizing calculator and many local energy programs offer sizing guidance. Online calculators from ACCA or equipment manufacturers get you close.
• Oversizing is worse than undersizing. Oversizing mini-splits causes short-cycling and humidity issues; the compressor cycles on and off rapidly, wears faster and fails to dehumidify in summer. Proper sizing prevents common comfort complaints in mini-splits. Undersizing means the space never fully warms up during deep cold snaps, but a properly sized unit running continuously at full output is more comfortable than an oversized unit cycling every few minutes.

SEER2, HSPF2 and Cold Climate Performance Ratings That Matter

Spec sheets list a dozen numbers. Here are the ones that actually determine whether a mini split system will heat your home well in winter.

SEER2 (Seasonal Energy Efficiency Ratio 2): measures cooling efficiency across a season. Higher is better for summer electricity bills. Zone Air's 24.0 and MRCOOL's 23.5 are both strong. But in a heating-dominant climate, SEER2 is secondary.

HSPF2 (Heating Seasonal Performance Factor 2): HSPF2 measures heating efficiency for heat pumps. This is the number to compare when heating is your primary reason for buying. Look for HSPF2 ratings of 10 or higher for cold-climate units. Zone Air hits 10.0; MRCOOL's 5th Gen 12k hits 10.2. Both are well above the minimum thresholds set by most rebate programs (typically 7.8 to 9.0).

Cold climate heating floor: the lowest outdoor temperature at which the unit still provides meaningful heat. Zone Air and MRCOOL standard 12k models both bottom out at −13°F (MRCOOL's operating range), and MRCOOL's higher-tier DIY models are rated lower. Cold climate heat pumps typically require performance ratings below freezing temperatures to earn cold climate certification.

Capacity at low temperatures: cold-climate heat pump criteria include maintaining at least 70% of nominal capacity at 5°F. MRCOOL's 5th Gen 12k delivers 8,400 BTU/h at 5°F, 70% of its 12,000 BTU/h rating at 47°F, with a COP of 2.08 (ENERGY STAR data). That is a capacity figure, not a floor: the standard 5th Gen keeps heating to about −13°F, MRCOOL's Easy Pro stops at 5°F, and higher-tier DIY models are rated lower. Zone Air publishes a COP2 of 2.1 at 5°F for its 12k, about the same efficiency at that temperature, but does not publish a 5°F capacity figure. ENERGY STAR recommends checking heating capacity at lower temperatures for heat pumps; always look beyond the nameplate 47°F rating.

Certification and rebate listings: ENERGY STAR certification and cold climate listings (NEEP ccASHP) are increasingly required for rebate eligibility. Zone Air units are AHRI Certified; if your program requires an ENERGY STAR or NEEP listing, check the exact model number against that list before you buy.

Voltage: Zone Air's 115V and 230V 12k models carry the same −13°F heating floor and 10.0 HSPF2, so the choice comes down to your electrical panel and the 1-point SEER2 gap in cooling (23 at 115V, 24 at 230V).

Cold Climate Performance: What to Expect from a 12,000 BTU DIY Mini Split in Winter

What if you had a 400 sq ft insulated bonus room in Minnesota? It's January, the outdoor temperature is −5°F. You're using a 12,000 BTU DIY heat pump to get warmth. Here's what happens.

Output drops as temperature drops. At 47°F (the standard rating point), Zone Air's 12k is rated at 12,600 BTU/h of heat and MRCOOL's at 12,000 BTU/h. At 5°F, the output from MRCOOL's unit has fallen to 8,400 BTU/h (70%). In freezing weather, a 12,000 BTU unit will lose some of its capacity. By −13°F, you can expect about 50 to 60% of nameplate output. Cold climate systems can maintain heating capacity well below freezing, but "maintain" does not mean "at full power." Standard 12,000 BTU units may drop output at low temperatures. This is physics, not a defect.

Defrost cycles. When frost has built on the outdoor coil, the system will switch briefly to melt it. During a defrost cycle (usually 2 to 10 minutes), the heating output will stop or drop. In humid cold climates, this may happen every 30 to 90 minutes when there is heavy frost on the coil. Below 0°F, cold-climate mini-splits can struggle because defrost cycles happen more often.

Backup heat. For regions where the design temperature drops below −13°F, treat the DIY mini split as your primary heat source above that threshold and pair it with backup heat (electric baseboard, wood stove, pellet stove) for deep cold snaps. This hybrid approach will keep heating bills low for 90%+ of the winter while covering the coldest nights.

Planning Your 12,000 BTU DIY Mini Split Installation Project

This is the planning stage, not a manual that shows you every step of the process. Good planning will prevent 80% of install problems.

• Indoor air handler placement: it should be mounted high on an exterior wall, centered on the room if possible. Keep it clear of curtains, shelves and ceiling corners. The indoor head needs open airflow to distribute heat evenly across the space.
• Outdoor unit placement: set the outdoor condenser on a stable pad or put mounting brackets on the wall. Make sure outdoor units have enough clearance so snow and ice don't get in the way. Put it away from roof edges where snow falls off, and where defrost water can drain freely without freezing on paths. Don't put the unit in direct sunlight on the south side if you can help it in hot-summer climates.
• Electrical planning: confirm whether you need 115V or 230V. Most DIY mini-splits are going to need a dedicated electrical line. You can't share a circuit with other appliances. Usually a 115V unit is going to need a dedicated 15A or 20A single-pole breaker. A 230V unit will need a double-pole breaker. Cold weather installs need you to plan carefully for the electrical and refrigerant connections. If your panel cannot support the load, you will want to hire an electrician. Many manufacturers need specific installation setups to preserve warranty coverage, including the correct wire gauge and breaker size.
• Tools and materials: a typical diy install is going to need a drill with a 3-inch hole saw, a level, a wrench set, a torque wrench, a stud finder and basic hand tools. For pre-charged systems like Zone Air, you are not going to need a vacuum pump or a gauge set. Non-precharged systems (Senville, Pioneer) are going to need a vacuum pump, manifold gauges and flaring tools.
• Permits and codes: check local building codes before you start. Some jurisdictions require a permit for HVAC work or electrical modifications. Improper DIY install can void warranties and reduce cold climate performance.

Step-by-Step Overview: Installing a 12,000 BTU DIY Mini Split Heat Pump

This overview gets you up to speed on the process, but actual installation must follow the specific manual for your Zone Air or other chosen mini split system.

Typical order of operations:

1. The indoor bracket gets mounted and the wall penetration gets drilled. Secure the mounting plate to wall studs, then drill a 3-inch hole through the exterior wall at a slight downward slope toward the outside for the line set, condensate drain and control cable.
2. Prepare and mount the outdoor condenser. It's set on a level pad or attached to a wall bracket. You'll check the space around it in your manual. In climates with a lot of snow you'll want to elevate the pad above the snow depth you expect.
3. Run the line set, control cable and condensate drain through the wall penetration. Protect the exposed lines with a line set cover to shield them from UV and weather.
4. Connect fittings. For Zone Air or MRCOOL DIY style units, attach the quick connect line sets per the manual and tighten to specified torque. For conventional systems you'll need to flare the copper, evacuate the lines with a vacuum pump, leak-test and charge with refrigerant.
5. Make electrical connections. Wire the disconnect box and breaker panel with power off, match polarity, and double-check wire gauge against what the manual needs.
6. Commission the system. Open service valves if applicable, power on and run an initial test cycle in both cooling and heating mode. Check that you have airflow, listen for unusual sounds and confirm the indoor air temperature rises in heating mode.

Safety: always lock out electrical breakers before you do any wiring. Use eye protection when you are drilling through walls. Do not try to do refrigerant work on non-DIY systems if you do not have the proper tools and training.

Time expectations: Zone Air's FAQ puts a single-zone wall install at 4 to 6 hours for two people who are doing it the first time. In cold climates, add an extra half-day to build a solid outdoor mounting base and to run the line set cover in a clean way.

DIY Mini Split vs Central AC, Baseboard and Space Heaters for Heating

A 12,000 BTU DIY mini split replaces or adds to resistance heating, and it does this more efficiently than any other single-room option.

• Operating cost: a baseboard heater that's running at 1,500 watts produces about 5,100 BTU/h at a COP of 1.0. At 30°F outdoor, a 12k heat pump at COP 2.5 is typical, and it produces 12,000 BTU/h while it's using about 1,400 watts. For the same heat delivered to a room, the mini split costs about 40% of what the baseboard costs in electricity. Window ac units do nothing for you in winter, and portable space heaters max out at COP 1.0.
• Central AC and ducts: it is rarely cost-effective to run new ducts to a single room. A ductless mini split system gets around that problem completely. Multi zone systems with multiple indoor air handlers exist for larger spaces, but for a single room, one outdoor unit and one indoor unit is all you need.
• Comfort: an inverter mini split changes its compressor speed to hold a steady temperature. Baseboard radiators have hot and cold layers. Space heaters blow and cycle. The mini split delivers heat that is even and quiet, and you get precise thermostat control.

Zone Air's 12k publishes a COP2 of 3.81 at 47°F and 2.1 at 5°F, so it delivers about 2 to nearly 4 times the heat of resistance heating per watt, depending on outdoor temperature.

Costs in 2026: DIY Install vs Hiring a Pro for a 12,000 BTU System

Here is what you would actually pay in 2026 for a 12,000 BTU cold climate mini split, with the costs broken into DIY and professional paths.

DIY 12k Zone Air project budget:

You can get a DIY mini-split for about $2,250 for equipment and supplies at the low end. You can save $1,500 to $3,500 in labor costs with DIY mini-split installation compared to hiring a contractor.

Professionally installed alternative:

Professional installation usually runs from $1,500 to $5,500 for labor alone. Professional installers may charge $3,000 to $6,000 for a single-zone unit including equipment. Depending on local rates and how easy it is to get to the spot, a pro-installed cold climate system like a Mitsubishi hyper heat 12k can run $5,000 to $10,000 total.

Tradeoff: DIY saves thousands but it may limit your access to certain utility rebates that need a licensed installer. With a hybrid approach, you do the mount and line-set yourself and you hire an electrician for the wiring. This keeps your costs low while it satisfies some program requirements.

Rebates and Incentives for DIY Mini Splits in 2026

The incentive landscape changed in 2026. Here is what actually applies.

• Federal tax credits: the federal 25C credit for heat pumps ended for equipment that was placed in service after December 31, 2025. There are no new federal credits that apply to mini split purchases in 2026.
• State HEAR (Home Electrification Appliance Rebates): state HEAR rebates pay up to $8,000 for heat pumps in some programs. Rebates can cover up to 100% of the costs for low-income households. Eligibility varies by state, and many programs are still giving out IRA-funded rebates through 2026. Check your state energy office or DSIRE list for the current listings.
• Utility rebates can provide $1,000 to $4,000 for installations. For example, Minnesota Power offers a $400 rebate for ENERGY STAR certified ductless mini splits, but it needs installation by a participating contractor. DIY installs do not qualify for that program. Most rebate programs follow this pattern: rebate eligibility often needs a licensed installer.
• DIY and rebates: DIY mini-split systems often lose their chance at utility rebates. Some programs focus only on equipment specs (SEER2/HSPF2 minimums) and do not specify installer type, but these are the exception. Always confirm the rules in your area before you count on rebate money. With Zone Air's free rebate calculator, you can do a quick first check.

Noise, Comfort and Daily Use of a 12,000 BTU DIY Mini Split

Beyond specs and install, day-to-day comfort determines whether you are happy with the system.

• Noise: most units produce indoor noise in the mid-20s to low-40s dB range when the fan is on low to medium. Zone Air's quiet mode floor is 30 dB, about the volume of a whisper. MRCOOL dips to ~18 dB at its lowest. For comparison, window ac units usually run 50 to 60 dB. In a home office or living room, 30 dB is effectively too quiet to hear over normal ambient sound.
• Air handler placement and drafts: in heating mode, set the vane to direct warm air downward and outward. Use auto fan rather than locking it on high. The inverter compressor will ramp up output as needed without blasting air. This prevents the "cold draft" feeling that some users report when the indoor air handler blows at full speed.
• Controls: Zone Air units include a remote with Follow Me sensing and app control, plus Alexa and Google Home voice control. Set the temperature for comfort (68 to 72°F is typical for heating), use programmable timers to reduce output overnight or when you are away, and let the system adjust itself. In humid climates or during the in-between seasons, the dehumidification function is useful when you need to deal with high humidity.

Maintenance Tips: Keeping Your DIY Mini Split Efficient in Cold Climates

Routine maintenance takes 15 minutes per month and it protects your investment for years.

• Indoor unit: clean or rinse the filters every 2 to 4 weeks when you're using the unit a lot. Once a year, gently brush or vacuum the coils and the blower wheel. Clogged filters are the number one cause of poor heating output and high electricity bills.
• Outdoor unit: clear snow and ice around the condenser after storms. Check that defrost water drains freely and does not refreeze on the pad. Keep leaves, grass clippings and debris away from the coil. Maintain the clearance zone you established at install.
• Preseason check each fall: check that the wall bracket or pad is stable and level. Look over the line set insulation for cracks or damage from animals. Verify condensate drain slope. Run a brief test in heating mode before the first cold night. Buying supplies during the off season often means you get better prices on pads, covers and replacement filters.
• Common problems: poor heating, ice buildup on the outdoor coil, and rising bills are almost always caused by airflow restrictions or blocked outdoor units. Both are easy to stop with regular DIY inspection.

With washable filters on every unit, Zone Air's DIY mini splits also include a manual plus a one-page spec sheet that covers upkeep.

When a DIY Mini Split Makes Sense, and When to Call a Pro

A 12,000 BTU DIY mini split isn't for everyone, so here's how to decide if it's right for you.

DIY makes sense when:

• You're comfortable using power tools, a drill and doing basic wiring.
• You're willing to read the manual from cover to cover and follow the steps with care.
• You've got a simple single zone layout: there's one room, there's one outdoor wall and the line set has clear access to run through.
• You want the right system for a bonus room, garage workshop or an extra indoor head for a space your central AC doesn't reach.

It's time to call a pro (or at least an electrician) when:

• Your electrical panel needs an upgrade or the wire run is longer than 30 feet.
• You're drilling through masonry, stone or a wall that's structural.
• You live where local codes require permitted HVAC work even for ductless systems.

If you later want to heat more than one room, a multi zone system with several indoor units off one outdoor unit can stay DIY too: Zone Air is the only DIY mini split that lets you mix wall-mount, ceiling cassette and concealed ducted units on one outdoor unit (as of November 2026), all on pre-charged line sets.

Zone Air is the best DIY-oriented brand for homeowners who choose to install themselves. We still encourage safe practices, permits and professional help where the project demands it. A professionally installed system is better than a poorly DIY-installed one. If the unit arrives and you change your mind before installing it, Zone Air takes returns on uninstalled units for 30 days.

Your next steps: choose the right 12,000 BTU model (Zone Air 12k for most cold climate buyers), confirm its cold climate performance matches your winter design temperature, size it against your square footage and heat load, plan the diy install and start heating your space for a fraction of what baseboard or resistance heat costs. The best diy mini split is the one that is installed correctly, sized properly and rated for your winters.

Related guides

• Best DIY mini split for heating - cold-climate picks for winter heat
• Best DIY heat pump for cold climates - MRCOOL Gen 4 vs 5th Gen and Zone Air
• Best 2-zone DIY mini split heat pump for cold climate - two rooms on one outdoor unit
• MRCOOL vs Zone Air - the two quick-connect systems side by side

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Specs and warranty terms are manufacturer-published as of November 2026, subject to change; verify before purchase. MRCOOL® and DIY 5th Gen are trademarks of their owner; Zone Air is a trademark of its owner. HVAC On Sale is not affiliated with or endorsed by MRCOOL.