Table of Contents
Summer heat that turns your home into a sauna isn’t just uncomfortable—it can feel downright oppressive, especially during those relentless multi-day spikes where the sun beats down from dawn until well past dusk. You might find yourself constantly battling sticky air, sky-high energy bills from an overworked central system, or struggling to cool specific rooms like a sun-drenched addition or a converted garage. The frustration of uneven temperatures or the noise of old window units can make finding relief feel impossible, leaving you desperate for a smarter, more efficient way to reclaim comfort without breaking the bank or sacrificing peace.
This is where ductless cooling systems, often called mini-splits, step in as a transformative solution for modern homeowners. Forget the limitations of ductwork-dependent setups or the inefficiency of portable units. Ductless technology offers targeted, whisper-quiet cooling tailored precisely to your living spaces, providing remarkable energy savings and customizable comfort zones. Understanding how to navigate the key features and considerations for selecting the right system for your unique home and climate is crucial—it’s not about chasing the “hottest” model, but finding the perfect fit that delivers reliable, efficient coolness exactly where and when you need it most.
Top 10 Ductless Cooling Systems
Detailed Product Reviews
1. MRCOOL 12000 BTU 115V Ductless Inverter Mini Split Air Conditioner & Heat Pump System, Easy Pro Series - Wall-Mounted AC Unit w/Heating and Cooling for Home, Office & Commercial Space
Overview: This 12,000 BTU ductless mini-split delivers year-round climate control for spaces up to 550 sq. ft., combining heating and cooling in a single wall-mounted unit designed for residential or light commercial use. Its 115V compatibility makes it accessible for standard household circuits.
What Makes It Stand Out: The 115V operation eliminates the need for complex 230V electrical upgrades, significantly simplifying DIY installation. MRCOOL’s focus on streamlined setup with pre-charged refrigerant lines reduces professional labor costs, while the inverter technology ensures quiet, efficient operation down to -4°F heating capability.
Value for Money: Priced competitively against professional HVAC installations, it offers substantial long-term savings through energy efficiency (up to 30% less power than non-inverter units). Though initial costs exceed window ACs, the dual heating/cooling functionality and DIY potential justify the investment for permanent solutions in small-to-medium rooms.
Strengths and Weaknesses: Pros include easy 115V installation, robust all-season performance, whisper-quiet operation, and space-saving design. Cons are the 550 sq. ft. limitation (unsuitable for larger areas) and lack of smart connectivity or advanced air filtration compared to premium models.
Bottom Line: An excellent DIY-friendly choice for efficiently heating or cooling compact spaces like bedrooms or offices, offering strong value through energy savings and simplified setup—ideal for budget-conscious homeowners avoiding electrical overhauls.
2. MRCOOL 18000 BTU 230V Ductless Inverter Mini Split Air Conditioner & Heat Pump System, Easy Pro Series - Wall-Mounted AC Unit w/ Heating and Cooling for Home, Office & Commercial Space
Overview: Targeting larger areas up to 800 sq. ft., this 18,000 BTU unit provides versatile heating and cooling for open-plan living spaces, garages, or small commercial zones. It operates on 230V and leverages inverter technology for consistent temperature management.
What Makes It Stand Out: The higher 18,000 BTU capacity bridges a critical gap between smaller and large-room units, efficiently covering spaces where 12k BTU models fall short. MRCOOL’s DIY-friendly design with pre-charged lines remains a standout, though 230V wiring requires basic electrical knowledge or minimal professional assistance.
Value for Money: While demanding a 230V circuit (a minor added cost), it delivers exceptional value for mid-sized areas by avoiding costly ductwork installations. Energy savings from inverter efficiency offset electricity bills faster than conventional ACs, making it cost-effective for常年 use in zones like sunrooms or workshops.
Strengths and Weaknesses: Strengths encompass powerful coverage for 800 sq. ft., reliable sub-zero heating, and quiet operation. Weaknesses include the necessity for 230V power (limiting retrofit ease) and the absence of smart features like app control, which some competitors now offer.
Bottom Line: A top recommendation for efficiently conditioning moderate-sized spaces where 12k BTU units are insufficient, balancing robust performance with DIY accessibility—perfect for homeowners upgrading from portable ACs seeking permanent, efficient solutions.
3. Mountman 12000 BTU Mini Split AC/Heating System,19 SEER2 110/120V Energy Efficient Ductless Inverter System,Cools Up to 750 Sq.Ft with Pre-Charged Condenser,Heat Pump & Installation Kits
Overview: This 12,000 BTU system cools up to 750 sq. ft. with 19 SEER2 efficiency, featuring R32 refrigerant and comprehensive DIY kits. It emphasizes user-friendly operation through multiple modes and maintenance innovations for residential comfort.
What Makes It Stand Out: Mountman excels with its four specialized modes (including ECO and Turbo Boost), ultra-quiet 26dB sleep operation, and intelligent self-cleaning/defrost functions. The pre-charged R32 refrigerant line set simplifies installation, while the washable filter and auto-maintenance features reduce long-term upkeep.
Value for Money: Offering broader coverage (750 sq. ft. vs. typical 550 sq. ft.) at a competitive price, it provides premium features like ECO mode (30% energy savings) without smart-tech premiums. The included installation kit and low maintenance needs enhance cost efficiency over time.
Strengths and Weaknesses: Pros are expansive room coverage, exceptional quietness, self-maintenance features, and strong energy savings. Cons include no WiFi/smart controls and reliance on manual remote operation, which feels outdated next to app-enabled rivals.
Bottom Line: Highly recommended for those prioritizing quiet, low-maintenance comfort in medium-large rooms; its ECO mode and self-cleaning justify the price, though tech-focused users may miss smart integrations.
4. MRCOOL 24000 BTU 230V Ductless Inverter Mini Split Air Conditioner & Heat Pump System, Easy Pro Series - Wall-Mounted AC Unit w/ Heating and Cooling for Home, Office & Commercial Space
Overview: Engineered for substantial areas up to 1,050 sq. ft., this 24,000 BTU unit delivers powerful heating and cooling for open-concept homes, basements, or commercial spaces using 230V power and inverter-driven efficiency.
What Makes It Stand Out: Its standout feature is high-capacity coverage—rare for DIY-focused mini-splits—without sacrificing MRCOOL’s signature easy installation. The unit maintains consistent comfort in extreme temperatures (down to -4°F) while operating quietly, ideal for larger zones where multiple smaller units would be impractical.
Value for Money: Though requiring 230V, it eliminates the expense of installing multiple systems for expansive areas. Energy savings from inverter technology make it economical for常年 use, particularly compared to central AC retrofits, offering long-term ROI through reduced utility bills.
Strengths and Weaknesses: Strengths include impressive 1,050 sq. ft. capacity, reliable all-weather performance, and DIY-friendly assembly. Weaknesses are the essential 230V circuit (limiting easy placement) and minimal smart features, lacking modern conveniences like app control.
Bottom Line: The go-to solution for efficiently conditioning large single zones; its robust output and installation simplicity make it invaluable for open layouts, though voltage requirements may deter some DIYers.
5. IDEALHOUSE 24,000 BTU Mini Split Air Conditioner and Heat Pump, 21 SEER2 Ultra Quiet 208-230V Ductless AC with WiFi & Alexa Control, Cools/Heats up to 1500 Sq.Ft, Easy Installation Kit
Overview: This premium 24,000 BTU system heats/cools expansive areas up to 1,500 sq. ft. with 21 SEER2 efficiency, featuring smart controls and ultra-quiet operation. It targets tech-savvy users needing powerful, connected climate management.
What Makes It Stand Out: Smart integration is key: WiFi/Alexa control enables remote adjustments and scheduling via app, while 28dB operation ensures near-silent comfort. The high 21 SEER2 rating and 40% energy savings over conventional units enhance its appeal for eco-conscious buyers.
Value for Money: Despite a higher upfront cost and mandatory professional installation (for warranty), its smart features, superior efficiency, and vast 1,500 sq. ft. coverage deliver exceptional long-term value. Energy savings and convenience justify the investment for large, tech-integrated homes.
Strengths and Weaknesses: Pros include best-in-class coverage, smart connectivity, whisper-quiet performance, and high efficiency. Cons are the non-negotiable professional install requirement and dual-box shipping, complicating setup versus true DIY models.
Bottom Line: Ideal for smart-home enthusiasts needing powerful, connected climate control in large spaces; prioritize it if budget allows for pro installation, but consider DIY models if hands-on setup is essential.
6. 9000 BTU Mini Split AC w/Remote Control19 SEER2 Cools Up to 450 Sq. Ft,Ductless Inverter Mini Split System w/0.75 Ton Heat Pump Pre-Charged & Installation Kit, Ultra-Quiet
Overview: This 9000 BTU ductless mini-split system delivers year-round climate control for spaces up to 450 sq. ft., featuring inverter-driven cooling and heating. ETL and AHRI certified, it targets bedrooms, garages, and small commercial areas with a pre-charged refrigerant setup and included installation kit.
What Makes It Stand Out: Its standout features include exceptional cold-weather performance (-4°F startup), ultra-quiet 23 dB operation, and a comprehensive 6-mode system (Cool, Heat, Dry, Eco, Auto, Fan) with advanced air purification via negative ions and PM2.5 removal. The all-weather design handles extremes up to 140°F and includes Wi-Fi compatibility and a 50-foot airflow range.
Value for Money: Priced competitively for its class, it offers strong value through energy savings (35% claimed), a robust installation kit, and dual cooling/heating functionality. While professional installation is required, the included components reduce setup costs versus bare-bones systems.
Strengths and Weaknesses: Strengths: Industry-leading quiet operation, versatile climate adaptability, thorough air purification, and rich feature set. Weaknesses: Requires professional installation (adding cost), ships in two packages (potential delay), and lacks explicit warranty details beyond certifications.
Bottom Line: An excellent choice for small-space comfort seeking quiet, efficient, and feature-rich performance, especially in variable climates. Ideal for users prioritizing air quality and willing to invest in professional setup.
7. MrCool Easy Pro 24k BTU 18.9 SEER2 Ductless Heat Pump Split System 5th Generation - DIY Mini Split w/ 16ft Lineset & 1 YR Labor Warranty by IWAE
Overview: The MrCool Easy Pro 24k BTU system is a DIY-focused ductless heat pump designed for areas up to 1,200 sq. ft., featuring 18.9 SEER2 efficiency and 11.2 HSPF2 heating performance. It emphasizes simplified installation with pre-charged refrigerant and includes a 16-foot lineset.
What Makes It Stand Out: Its defining trait is true DIY accessibility via MrCool’s “Easy” line valves, eliminating vacuum-pump requirements. Gold Fin corrosion-resistant coating enhances outdoor unit longevity, and the 1-year labor warranty (rare for DIY units) significantly reduces installation risk.
Value for Money: Outstanding value for competent DIYers, as the included labor warranty and pre-charged design bypass costly professional fees. Higher upfront cost than basic kits is justified by time savings, durability features, and peace of mind from warranty coverage.
Strengths and Weaknesses: Strengths: Genuine DIY installation capability, robust corrosion protection, valuable labor warranty, and broad coverage (500–1,200 sq. ft.). Weaknesses: Still technically demanding for novices, slightly lower SEER2 than premium models, and limited smart features.
Bottom Line: Highly recommended for experienced DIYers needing reliable, large-space heating/cooling. The labor warranty and user-friendly design make it a cost-effective, low-risk investment for hands-on homeowners.
8. Cooper & Hunter 24,000 BTU, 230V, 17 SEER Ductless Mini Split AC/Heating System Pre-Charged Inverter Heat Pump with 16ft Installation Kit
Overview: This commercial-grade 24,000 BTU (2-ton) Cooper & Hunter system delivers powerful cooling and heating for large areas (up to 1,200 sq. ft.), featuring 18 SEER2 efficiency, smart app control, and a pre-charged refrigerant setup. UL and AHRI certified for reliability.
What Makes It Stand Out: It excels in heavy-duty applications with robust build quality, smartphone-enabled smart control via app, and reliable operation down to 5°F. The pre-charged design with included 16ft line set, drainage, and communication cables streamlines professional installation.
Value for Money: Premium pricing aligns with its commercial durability and smart features. While not DIY-friendly, the comprehensive kit reduces labor time, and the energy-efficient inverter justifies long-term operational savings for high-usage environments like offices or server rooms.
Strengths and Weaknesses: Strengths: Excellent for large/commercial spaces, smart app integration, high-quality pre-charged installation kit, and strong cold-weather performance. Weaknesses: Requires professional installation (no DIY option), lacks explicit noise specs, and higher voltage (230V) limits outlet compatibility.
Bottom Line: A top-tier solution for commercial or large residential spaces prioritizing durability, smart control, and efficient performance. Best suited for users with access to professional HVAC services.
9. YITAHOME 12000 BTU Mini Split Air Conditioner Heat Pump System, Wifi Enabled 20 SEER2 115V Inverter Ductless AC Cool Up to 750 Sq. Ft, Compatible with Alexa, Complete Installation Kit, White
Overview: The YITAHOME 12k BTU system offers 750 sq. ft. coverage with 20 SEER2 efficiency, 115V convenience, and Alexa/Wi-Fi smart control. ETL and AHRI certified, it includes a complete installation kit and targets bedrooms, living areas, and light commercial use.
What Makes It Stand Out: Key highlights are its 115V compatibility (simpler wiring), Alexa integration, and sub-41 dB quiet operation. Advanced features include negative ion air purification, PM2.5 removal, and wide temperature tolerance (-4°F to 118°F), all manageable via smartphone.
Value for Money: Competitive pricing for its smart capabilities and high SEER2 rating. The included installation kit and energy savings (25% claimed) enhance value, though professional installation costs remain a factor. Beats pricier brands on features per dollar.
Strengths and Weaknesses: Strengths: User-friendly 115V setup, excellent air quality features, strong smart-home integration, and quiet operation. Weaknesses: Professional installation mandatory, lacks explicit labor warranty, and missing shut-off valves in kit.
Bottom Line: Ideal for tech-savvy homeowners seeking quiet, air-purifying comfort in medium spaces. The smart features and voltage flexibility make it a compelling, efficient choice despite installation requirements.
10. MEPTY 12000BTU Mini Split AC/Heating System, 19 SEER2 Energy Efficient Mini Split Air Conditioner with Heat Pump, Cools Up to 750sq.ft, Ductless Inverter AC Unit with Pre-Charged Condenser
Overview: MEPTY’s 12k BTU system provides 750 sq. ft. cooling/heating with 19 SEER2 efficiency, R32 refrigerant, and a pre-charged design. It emphasizes rapid temperature changes (30s cooling/60s heating) and quiet operation, targeting residential and light commercial use.
What Makes It Stand Out: Its rapid cooldown capability, eco-friendly R32 refrigerant, and 4-in-1 functionality (cooling, heating, fan, dehumidifying) with 4D airflow stand out. The 35 dB “mute mode” and 41°F low-temperature heating expand usability in diverse climates.
Value for Money: Strong value proposition with 36% energy savings claims and included essentials. R32’s efficiency and lower environmental impact justify cost versus older refrigerants, though professional installation remains necessary.
Strengths and Weaknesses: Strengths: Exceptional speed, eco-friendly refrigerant, versatile 4-mode operation, and ultra-quiet mute mode. Weaknesses: No smart/Wi-Fi features, basic remote-only control, and lacks detailed air purification specs.
Bottom Line: A practical, efficient pick for users prioritizing fast, quiet climate control without smart tech. Best for budget-conscious buyers wanting reliable performance and environmental benefits from R32 refrigerant.
Understanding Ductless Cooling Technology
How Ductless Systems Differ from Traditional AC
Unlike central air conditioners that rely on extensive duct networks to distribute cooled air throughout an entire house, ductless systems operate on a fundamentally different principle. They consist of an outdoor compressor unit connected via refrigerant lines to one or more discreet indoor air-handling units mounted on walls or ceilings. This direct connection eliminates the significant energy losses (often 20-30%) common in ducted systems, especially those with older or poorly insulated ductwork running through unconditioned spaces like attics.
The Core Components Explained
Every ductless system has two essential parts working in harmony: the outdoor condenser/compressor unit, which expels heat outside, and the indoor evaporator unit(s), which blows cool air into your living space. These are linked by small, insulated refrigerant lines and a conduit carrying power and drainage. The absence of ducts is the defining feature, allowing for flexible installation in locations where traditional systems are impractical or prohibitively expensive to install.
Why Inverter Technology Matters Most
The heart of modern ductless efficiency lies in inverter-driven compressors. Unlike older systems that simply turn the compressor on and off at full blast, inverter technology continuously adjusts the compressor speed to match the precise cooling demand. This means the system runs quieter, avoids uncomfortable temperature swings, and uses significantly less energy—especially during partial-load conditions, which occur most of the time in real-world use.
Key Factors for Choosing Your System
Accurately Sizing Your Cooling Needs
Oversizing is a common and costly mistake. A unit too large for the space will cycle on and off too frequently (“short cycling”), failing to properly dehumidify the air and wasting energy. Undersizing leaves the system struggling to reach the desired temperature. Proper sizing requires a detailed calculation (Manual J load calculation) considering room dimensions, ceiling height, insulation levels, window size/orientation, and local climate—not just square footage.
Decoding Efficiency Ratings: SEER and HSPF
The Seasonal Energy Efficiency Ratio (SEER) is the primary metric for cooling efficiency; higher SEER numbers indicate greater efficiency. For ductless systems, look for models starting around 18 SEER, with premium options exceeding 25 SEER. If considering a heat pump (providing both heating and cooling), the Heating Seasonal Performance Factor (HSPF) is equally important. Higher ratings mean lower operating costs, though often at a higher upfront price—calculate the long-term savings for your usage patterns.
Single-Zone vs. Multi-Zone Configurations
Single-zone systems connect one indoor unit to one outdoor unit, ideal for cooling a single room, garage, or small apartment. Multi-zone systems connect multiple indoor units (typically 2-8) to a single outdoor condenser, allowing independent temperature control in different rooms or zones. Multi-zone offers greater flexibility and potential cost savings on the outdoor unit, but requires careful planning of refrigerant line lengths and capacities for optimal performance.
Installation and Environmental Considerations
Evaluating Your Home’s Suitability
Ductless systems excel in homes without existing ductwork (like older homes, additions, or converted spaces), but are also excellent retrofits for supplemental cooling or zoning in ducted homes. Consider wall or ceiling space for indoor units, accessibility for mounting, and the path for running the small refrigerant lines (typically 3-4 inches of wall penetration). Attic or crawlspace access for line routing is often beneficial.
The Critical Importance of Professional Installation
While the concept seems simple, ductless installation is highly technical. Refrigerant line charging, vacuuming lines to remove moisture, proper mounting, drainage setup, and electrical connections require specialized tools and expertise. Poor installation is the leading cause of performance issues, reduced efficiency, and premature failure. Always choose a certified, experienced installer—this is not a DIY project.
Noise Levels: What to Expect Indoors and Out
Modern ductless indoor units are remarkably quiet, often operating between 19-42 decibels (dB) on the lowest fan setting—quieter than a whisper or library. Outdoor unit noise varies but generally ranges from 45-55 dB, comparable to moderate rainfall. Pay attention to the specific dB ratings at different fan speeds, especially if installing near bedrooms or living areas, and discuss placement options with your installer to minimize sound impact.
Features Enhancing Comfort and Control
Smart Connectivity and App Control
Many modern systems integrate seamlessly with Wi-Fi, allowing control via smartphone apps from anywhere. Schedule temperature changes, monitor energy usage, receive maintenance alerts, and integrate with smart home ecosystems (like Alexa or Google Home). This level of remote management significantly enhances convenience and potential energy savings through precise scheduling.
Advanced Air Filtration and Purification
Beyond cooling, indoor units often incorporate multi-stage filtration systems. Look for features like washable pre-filters, antimicrobial treatments, and sometimes advanced options like plasma or photocatalytic filters that capture dust, pollen, pet dander, and even neutralize odors or certain airborne contaminants, improving overall indoor air quality.
Customizable Airflow Patterns and Fan Settings
Sophisticated indoor units offer multiple airflow directions (up/down, left/right) and fan speeds. Features like “Comfort Airflow” gently sweep air across the room to prevent drafts, while “Turbo” mode provides rapid cooling. Auto-reviving airflow settings ensure even temperature distribution without constant manual adjustment, enhancing comfort in various room layouts.
Long-Term Value and Maintenance
Calculating True Cost of Ownership
Look beyond the initial purchase price. Factor in installation costs, potential electrical upgrades, estimated annual energy costs (based on SEER rating and your usage), and expected lifespan (typically 15-20 years with proper care). A higher-efficiency model might cost more upfront but often pays for itself through lower utility bills over its lifetime, especially in regions with long cooling seasons.
Essential Maintenance for Peak Performance
Ductless systems require surprisingly simple upkeep for homeowners: regularly cleaning or replacing the easily accessible washable air filters (monthly during peak season) prevents airflow restriction and maintains efficiency. Professional maintenance (annually) is crucial and includes checking refrigerant levels, cleaning coils, inspecting drainage, and verifying electrical components—keeping the system running smoothly and efficiently for years.
Warranty Coverage: What Really Protects Your Investment
Warranties vary significantly. Standard coverage is often 5-7 years on the compressor and 5 years on parts. Some manufacturers offer extended warranties (up to 12 years) on the compressor with registration. Pay close attention to what’s covered (parts, labor, refrigerant), exclusions (like improper installation), and whether the warranty is pro-rated. A strong warranty reflects the manufacturer’s confidence in their product.
Environmental and Practical Advantages
Significant Energy Savings Potential
By eliminating duct losses and utilizing inverter technology, ductless systems can reduce cooling energy consumption by 20-50% compared to older central systems or window units, particularly in mild or shoulder seasons where they run at partial capacity. This translates directly to lower electricity bills and a reduced carbon footprint for your home cooling.
Zone Control: Cooling Only Where You Are
The ability to heat or cool individual rooms independently is a game-changer. There’s no need to cool unoccupied bedrooms or the guest room, drastically cutting wasted energy. This personalized comfort means everyone in the household can enjoy their preferred temperature in their own space, enhancing overall satisfaction without overcooling the entire structure.
Ideal Applications Beyond Whole-House Cooling
Ductless systems shine in specific scenarios: adding air conditioning to room additions without extending ductwork, cooling sunrooms or finished basements, providing efficient climate control for garages or workshops, and serving as a primary solution for tiny homes or historic properties where duct installation is impossible. Their versatility solves cooling challenges other systems simply can’t address.
Frequently Asked Questions
How much does a typical ductless system installation cost?
Installation costs vary widely based on system size (single vs. multi-zone), number of indoor units, brand efficiency, and home specifics, but generally range from $3,000 to $10,000+ before potential rebates. Get multiple detailed quotes from certified installers.
Can ductless systems provide both heating and cooling?
Yes, most modern ductless “mini-splits” are heat pumps, capable of providing efficient heating (often down to -15°F or lower with newer models) and cooling from a single outdoor unit, making them a year-round solution.
How long do ductless cooling systems typically last?
With proper installation and regular maintenance (including annual professional check-ups), a quality ductless system can reliably operate for 15 to 20 years.
Are ductless systems noisy inside the house?
No, indoor units are designed for quiet operation, typically ranging from 19-42 dB on low settings—much quieter than traditional window units or central system blowers. Higher fan speeds increase noise slightly.
Do I need a separate system for each room?
Not necessarily. Multi-zone systems allow one outdoor unit to connect to multiple indoor units (usually 2-8), each controlling a separate room or zone independently, offering flexibility without multiple outdoor condensers.
How often do ductless systems need professional servicing?
At minimum, schedule a professional tune-up once a year, ideally before the peak cooling season. Homeowners should clean the air filters monthly during heavy use.
Can I install a ductless system myself to save money?
No. Refrigerant handling requires EPA certification, electrical work must meet code, and improper installation severely impacts performance, efficiency, and safety. Always use a licensed, experienced professional.
Will a ductless system work well in a very hot climate?
Yes, modern high-efficiency ductless systems are specifically engineered for demanding climates and often outperform traditional central AC in extreme heat due to their precise capacity control and lack of duct losses.
How do ductless systems handle humidity control?
By running continuously at lower speeds (thanks to inverter technology), they remove moisture more effectively than traditional systems that cycle on/off, leading to a more comfortable, less clammy environment.
Are there rebates or tax credits available for ductless systems?
Yes, frequently! Check DSIRE (Database of State Incentives for Renewables & Efficiency), federal tax credits (like the Inflation Reduction Act provisions), and local utility company programs for potential significant savings on high-efficiency models.
See Also
- 10 Best Ductless Cooling Systems for Humid Summers This Year
- 10 Best Ductless Cooling Systems for Sunrooms and Additions This Year
- 10 Best Ductless Cooling Systems for Summer Relief This Year
- 10 Best Ductless Cooling Systems for Hot & Humid Regions in 2026
- Top 10 Best Ductless Mini Split Systems for Home Cooling and Heating in 2026