A garage without windows turns into an oven the moment summer hits. Standard window units are useless, and the heat soak from concrete floors and metal doors makes the space unbearable for working, storing sensitive gear, or simply walking into without breaking a sweat. The only workable solution is a powerful portable air conditioner paired with a creative through-wall or through-door venting strategy that seals the heat out and the cold in.
I’m Mohammad Maruf — the founder and writer behind Gardening Beyond. I spend my time comparing the real-world performance specifications of portable HVAC gear, studying how BTU ratings degrade without proper intake venting, and analyzing aggregated owner feedback from hundreds of buyers who have already solved the same windowless challenge.
This guide covers the cooling power, hose configurations, and noise levels that define the best ac for garage with no windows. You will learn exactly which models handle sealed environments and how to install them so your garage stays cold without a single window pane.
How To Choose The Best AC For Garage With No Windows
Selecting a portable AC for a sealed garage is different from buying one for a bedroom with a standard window. You need to prioritize venting efficiency, continuous drainage, and the raw BTU output needed to overcome the heat load from uninsulated walls and large garage doors. These are the critical factors to consider.
Single Hose versus Dual Hose Venting
In a windowless garage, the air the AC exhausts outside must be replaced by air pulled from somewhere. A single-hose unit draws replacement air from inside the conditioned space, creating negative pressure that pulls hot outdoor air in through every gap under the garage door. A dual-hose unit uses a second hose to bring outdoor air directly to the condenser for cooling, so it does not depressurize the garage and leaves your cold air where it belongs. Dual-hose is the only reliable choice for a sealed workshop or garage.
BTU Rating and Garage Square Footage
Standard BTU sizing assumes a moderately insulated room with windows. A garage with thin walls, concrete slab, and a large metal overhead door loses cold much faster. You need to oversize the unit by roughly 20 percent. For a typical two-car garage around 500 to 600 square feet, a 14,000 BTU ASHRAE unit is the baseline. For larger garages approaching 800 square feet, step up to 16,000 BTU ASHRAE models to maintain a comfortable temperature during peak afternoon heat.
Self-Evaporating Drainage
Garages rarely have a floor drain or easy access to a sink for emptying a condensate bucket. A unit with a self-evaporating system uses the hot condenser coil to evaporate collected moisture back into the exhaust air stream. This eliminates the need to drain water manually during normal operation. In high-humidity environments above 85 percent, even the best self-evap systems may need a gravity drain hose, so check for a rear drain port that can be routed to a shop sink or outside.
Noise Level in a Workspace
A garage AC runs for long hours, often while you are trying to work or rest. Look for units that advertise 45 dB or lower in sleep or inverter mode. Compressor noise in traditional fixed-speed units creates a constant drone, whereas inverter-driven compressors ramp down when the target temperature is reached, dropping the noise floor significantly. If you plan to run the AC overnight for a garage gym or guest room conversion, an inverter model is worth the premium.
Venting Strategy for No Windows
Without a window, you need a plan for the exhaust hose. A through-wall vent kit requires cutting a 6 to 7 inch hole in the wall and installing a louvered vent cover. A through-door solution uses a plywood panel fitted into the garage door track with a cutout for the hose adapter. Drop-ceiling installations route the hose into the attic space above, provided the attic itself has soffit vents for heat escape. Make sure the unit you choose comes with a long enough hose — at least 59 inches — to reach your chosen vent location without requiring extension pieces that reduce cooling performance.
Quick Comparison
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| Model | Category | Best For | Key Spec | Amazon |
|---|---|---|---|---|
| Whynter ARC-1230WN | Premium Dual Hose | High-efficiency inverter cooling | 14,000 BTU, 12.3 CEER | Amazon |
| ZAFRO 16,000 BTU | Inverter Dual Hose | Largest coverage with app control | 16,000 BTU, 42 dB | Amazon |
| Gasbye 14,000 BTU | Inverter Dual Hose | Peak energy efficiency (13.6 CEER) | 14,000 BTU, 13.6 CEER | Amazon |
| Garvee 14,000 BTU Inverter | Dual Hose Heat Pump | Year-round heating and cooling | 14,000 BTU, 42 dB | Amazon |
| DREO 516S 14,000 BTU | Premium Single Hose | Quiet operation and smart controls | 14,000 BTU, 45 dB | Amazon |
| YLEOOB 16,000 BTU | Mid Range Single Hose | High BTU for budget-friendly price | 16,000 BTU, 42 dB | Amazon |
| Augsmile 16,000 BTU | Mid Range Single Hose | Coverage up to 850 sq ft | 16,000 BTU, 40 dB | Amazon |
| QLF 16,000 BTU | Mid Range Single Hose | No-drain cooling for large rooms | 16,000 BTU, 40 dB | Amazon |
| DREO 318S 8,000 BTU | Entry Level Single Hose | Small workshop or personal cooling | 8,000 BTU, 45 dB | Amazon |
| EUHOMY 14,000 BTU | Value Single Hose | All-season cooling with heat mode | 14,000 BTU, 7.9 CEER | Amazon |
| Garvee 14,000 BTU | Budget Single Hose | Affordable entry for small garages | 14,000 BTU, 48 dB | Amazon |
In‑Depth Reviews
1. Whynter ARC-1230WN 14,000 BTU
The Whynter ARC-1230WN is the gold standard for garage cooling because its dual-hose inverter design completely eliminates the negative pressure issue that plagues single-hose units in sealed spaces. The hose-in-hose exhaust and intake system pulls combustion air from outside rather than borrowing your cooled garage air, which keeps the temperature stable even when the unit has been running for hours. With a 12.3 CEER rating, this unit uses 40 percent less energy than a typical fixed-speed portable AC, making it a strong choice for long work sessions.
The self-evaporating auto-drain function handles up to 87 pints of condensate per day without requiring a bucket, which is critical for a garage floor that lacks a drain. The NetHome Plus app gives you scheduling capability so you can pre-cool the garage before you step into it, a huge advantage for early morning workshop use. Owners report that the unit holds a steady temperature even in Arizona garages where outdoor temps exceed 110°F, though the compressor noise becomes noticeable at maximum fan speed.
The window installation kit extends up to 82 inches, but for a windowless garage you will need to build a through-wall or through-door panel. The unit itself weighs nearly 80 pounds, so plan for two-person setup. The three-year warranty and Forbes Vetted award reinforce its reliability for demanding environments where cheaper units would fail within one season.
What works
- Dual-hose design maintains neutral pressure in sealed garages
- Inverter compressor delivers exceptional energy efficiency at 12.3 CEER
- Self-evaporating system handles condensation without manual draining
- Smart app enables scheduling for pre-cooling before use
What doesn’t
- Very heavy at 80 pounds, requires two people to move
- Window kit needs modification for non-standard openings
- Remote sensor range can be finicky in direct line-of-sight
2. ZAFRO 16,000 BTU Dual Hose Inverter
The ZAFRO 16,000 BTU dual hose unit brings inverter technology to a higher BTU bracket, making it one of the strongest options for oversized garages up to 800 square feet. Its dual-hose configuration with 500 cubic meters per hour airflow ensures that even a poorly insulated garage gets blasted with cold air quickly. The Extra mode locks the compressor at full power and drops the set point to 61°F, which is exactly what you need when the garage door has been baking in direct sun all afternoon.
Noise sits at 42 dB in normal operation, and the inverter compressor ramps down frequency rather than cycling on and off, so the sound profile is a consistent low hum rather than disruptive rattling. The 72-hour drainage-free claim holds up in most environments below 90 percent humidity, meaning you can run the unit all weekend without touching a drain hose. The ZAFRO app controls all six modes including Cool, Dry, Fan, Sleep, Extra, and Eco, plus four-way oscillation distributes air horizontally and vertically to eliminate hot corners.
The main downside is the physical footprint — at 66 pounds and with dual hoses, it takes up more floor space than single-hose competitors. The included window panels work for standard sliding windows, but owners report that the plastic brackets feel lighter than the unit itself. For a permanent through-wall installation, you will need to reinforce the vent panel or build a dedicated plywood adapter plate to prevent the heavy hose assembly from pulling the seal loose.
What works
- 16,000 BTU capacity handles large, uninsulated garages effectively
- Dual-hose inverter design prevents negative pressure and saves energy
- Extra mode provides maximum cooling on demand at 61°F set point
- Four-way swing ensures even air distribution across the space
What doesn’t
- Plastic window brackets feel less durable than the unit itself
- Unit is large and heavy, difficult to reposition frequently
- Requires careful through-wall sealing for permanent garage installation
3. Gasbye 14,000 BTU Dual Hose Inverter
The Gasbye 14,000 BTU unit achieves a 13.6 CEER rating — one of the highest verified efficiency scores in the portable AC market — which translates directly into lower electricity bills for a garage that runs the AC eight to ten hours a day. Its full DC inverter compressor adjusts output between 500 and 1,300 watts depending on cooling demand, so it uses half the power of a traditional fixed-speed unit when the garage has already reached a comfortable temperature. The dual-hose system with two 59-inch hoses eliminates the negative air pressure that would pull hot air in through the garage door gaps.
In inverter mode, the compressor drops to 50 percent load within two minutes and noise falls to around 45 dB, which is quiet enough for a garage gym while you are lifting or stretching. The backlit remote and display-off feature make it easy to use with the lights dimmed for overnight cooling. Gasbye backs the unit with a three-year quality guarantee that includes full replacement units, not refurbished models, and customer reports confirm that support typically responds within 12 hours if an issue arises.
The thermostat sensor sits above the hot discharge line, which can cause the unit to overcool the space before cycling off. A simple piece of foil taped over the discharge area fixes this without voiding the warranty. The window kit uses thin plastic that does not seal as tightly as a custom plywood panel, so for a garage installation you will want to build your own vent board for the door or wall cutout.
What works
- 13.6 CEER is the highest efficiency in this class, saving significant energy
- Inverter mode provides whisper-quiet operation at 45 dB
- Full DC inverter adjusts power from 500W to 1,300W as needed
- Three-year warranty with full replacement units, not refurbished
What doesn’t
- Thermostat placement near hot discharge line can cause overcooling
- Window kit plastic is thin and does not seal tightly
- Unit is large and heavy, requires planning for placement
4. Garvee 14,000 BTU Inverter Dual Hose
The Garvee 14,000 BTU inverter unit stands out because it includes a heat pump mode that provides heating down to 50°F, making it a true year-round solution for a garage that doubles as a workspace in both summer and winter. The dual-hose system with two 59-inch hoses ensures the intake and exhaust stay separated so the condenser never recirculates hot air back into the garage. The smart inverter compressor maintains temperature without the loud start-stop cycle of traditional units, and the 42 dB sleep mode is quiet enough for a garage converted into a guest bedroom.
The dehumidifier function removes up to 84.5 pints per day, which is useful for garages that collect moisture from rain-soaked cars or humid outdoor air pulled in when the main door opens. The follow-me remote has an I-Sense feature that measures temperature at the remote location rather than at the unit, so the AC cools to the temperature where you are actually working. The 24-hour timer and auto-swing louvers add convenience for scheduling and airflow distribution.
At 66 pounds and with two hoses plus a drain hose for continuous dehumidifier operation, this is not a unit you will move daily. The window kit fits openings from 52 to 100 centimeters, but for a windowless garage you will need a custom through-wall or through-door panel. Some owners note that the heat pump struggles when garage temperatures drop below 50°F, so in cold climates you may still need a separate heater for deep winter months.
What works
- Integrated heat pump provides supplemental warmth in cool weather
- Dual-hose design maintains neutral pressure in sealed spaces
- Follow-me remote measures temperature at your location
- Inverter compressor runs quietly at 42 dB on sleep mode
What doesn’t
- Heating capacity drops significantly below 50°F outdoor temperature
- Heavy 66-pound chassis requires planning for permanent placement
- Window kit plastic does not provide a tight garage-grade seal
5. DREO 516S 14,000 BTU
The DREO 516S is a premium single-hose unit that leverages DREO’s patented IceCool system and noise isolation to deliver strong cooling with very low sound output. The 14,000 BTU ASHRAE rating translates to 10,000 BTU SACC, which is enough for a garage up to 400 square feet, and the airflow reaches up to 16 feet from the unit. The patented drainage-free system uses sensors and a pump to evaporate condensate automatically in environments up to 90 percent humidity, which keeps the garage floor dry without a drain hose.
Noise levels stay at 45 dB thanks to the rotary scroll compressor and acoustic isolation, making this one of the quietest single-hose options for a garage where you want to run power tools or listen to music without AC interference. The DREO app integrates with Siri, Alexa, and Google Home, and the sleep curve feature lets you set temperature adjustments over time rather than a single static set point. The magnetic remote holder and dimmable LED display are small touches that make nighttime use more convenient.
As a single-hose unit, the DREO 516S will create negative pressure in a sealed garage, pulling hot air in through door gaps. This is acceptable for a garage that has some air leakage or if you run the unit only when the main door is partially cracked for venting. The 16-foot reach means placement matters — you need to position the unit centrally or use a fan to circulate air to the far corners. The setup requires extra foam sealing around the window kit to prevent hot air infiltration, and the hose connection can be difficult to seat properly on the first attempt.
What works
- IceCool system delivers strong cold airflow within 30 minutes
- Patented drainage-free design works up to 90% humidity
- Very quiet at 45 dB, suitable for work or sleep environments
- Smart app integrates with Alexa and Google Home for hands-free control
What doesn’t
- Single-hose design creates negative pressure in a fully sealed garage
- Setup requires extra foam for airtight window or door sealing
- Hose connection can be difficult to seat without gaps
6. YLEOOB 16,000 BTU Portable AC
The YLEOOB 16,000 BTU portable AC offers the highest raw BTU output in the mid-range category, making it an attractive option for large garages that do not require the efficiency premium of an inverter. The rotary scroll compressor cools spaces up to 730 square feet, and the self-evaporation system eliminates the need to drain water during normal cooling cycles. The 42 dB sleep mode is genuinely quiet for a non-inverter unit, allowing overnight use in a garage that serves as a secondary living space.
The 5-in-1 functionality includes cooling, fan, dehumidifier, sleep mode, and a 24-hour timer, and the WiFi app integration lets you monitor energy usage and pre-cool the space before arriving. The auto-swing function distributes air across a wide arc, which helps mitigate hot spots in rectangular garages where the AC must be placed off-center. The hidden handles and 360-degree wheels make it easy to roll into position despite the unit’s size.
Being a single-hose configuration, this unit will depressurize a fully sealed garage. In a space that has a standard garage door with bottom weatherstripping that allows some infiltration, the negative pressure effect is less pronounced, but it is still present. The window kit includes a variety of panel combinations, but for a garage installation you will want to build a custom vent panel to ensure a tight seal. The 900 kWh annual energy consumption is higher than inverter models, which matters if you plan to run the unit more than eight hours daily during summer.
What works
- 16,000 BTU provides powerful cooling for large garages
- Self-evaporating system eliminates manual drainage in normal use
- WiFi app allows pre-cooling and schedule management
- Auto-swing louvers help distribute cold air evenly
What doesn’t
- Single-hose design pulls in hot air through garage door gaps
- Energy consumption at 900 kWh per year is higher than inverter models
- Window kit panels need modification for custom through-wall setups
7. Augsmile 16,000 BTU Portable AC
The Augsmile 16,000 BTU portable AC claims coverage up to 850 square feet, making it a strong candidate for oversized garages or workshops where a single unit must condition the entire space. The 450 cubic meters per hour airflow ensures that cold air reaches the far corners even when the unit is placed against a wall. The noise-reduction compressor operates at just 40 dB in sleep mode, which is quieter than many library-rated units and suitable for a garage that doubles as a recording space or home gym.
The 5-in-1 mode selection covers cooling, fan, dehumidifier, sleep, and a 24-hour timer. The WiFi connectivity via the Smart Life app allows full remote control, and the leak-proof construction is a welcome detail for a garage where water spills can damage stored equipment. The casters and side handles make rolling the 43-pound unit manageable, though the weight is still significant for frequent repositioning.
The single-hose design is the primary limitation for a windowless garage application. Owners report that the unit cools quickly in rooms with some natural air exchange, but in a fully sealed garage the negative pressure effect will pull hot air through the garage door weatherstripping. The included window kit fits 25 to 50 inch sliding windows, so for a garage installation you will need to fabricate a wall or door panel. The 1,158 kWh annual energy consumption is on par with other non-inverter 16,000 BTU units, but it is noticeably higher than dual-hose inverter alternatives in this guide.
What works
- Claims the largest coverage area at 850 square feet
- Operates at a genuinely quiet 40 dB in sleep mode
- Leak-proof structure provides peace of mind on concrete floors
- WiFi app control with Smart Life integration
What doesn’t
- Single-hose design is not ideal for fully sealed garages
- Energy consumption is higher than dual-hose inverter models
- Window kit requires custom adaptation for no-window installation
8. QLF 16,000 BTU Portable AC
The QLF 16,000 BTU portable AC is a solid mid-range option that balances high cooling output with very low noise, operating at a minimum of 40 dB in sleep mode. The no-drain technology automatically manages condensation, which is a practical advantage in a garage without a floor drain. The 550 to 800 square foot coverage range fits most two-car garages, and the airflow reaches up to 18 feet to cool the far workbench area.
The 5-in-1 modes include cooling, three-speed fan, dehumidifier, sleep, and a 0.5 to 24 hour timer. The Smart Life app provides full scheduling and temperature management, and the 35 to 80 degree auto-swing helps distribute air when the unit is placed in a corner. The 360-degree casters and side handles enable quiet movement across the garage floor, and the child lock safety feature is useful if the garage is accessible to children.
The single-hose configuration is the same limitation as other mid-range units in this category. In a sealed garage, the negative pressure effect will be noticeable, and you may need to crack the man-door or install a passive vent to allow makeup air. The 577 kWh annual energy consumption is surprisingly low for a 16,000 BTU unit, but this figure may reflect a specific test condition rather than real-world usage in a hot garage. The included window kit works for sliding windows, but for a windowless garage you will need to build a custom adapter panel.
What works
- High 16,000 BTU output for large garages up to 800 sq ft
- Operates at an impressively low 40 dB in sleep mode
- No-drain technology eliminates manual water removal
- Smart Life app provides full scheduling and remote control
What doesn’t
- Single-hose design not suited for fully sealed spaces
- Stated energy consumption seems optimistic for real-world garage use
- Window kit needs custom adaptation for wall or door installation
9. DREO 318S 8,000 BTU
The DREO 318S is the smallest unit in this lineup at 8,000 BTU ASHRAE, but it brings the same patented IceCool and noise isolation technology found in the larger 516S model. For a small single-car garage or a dedicated workshop space up to 150 square feet, this unit delivers rapid cooling that owners consistently describe as colder and faster than larger units they have owned previously. The smart inverter compressor adjusts output continuously, so it does not cycle on and off like a fixed-speed unit, maintaining a steadier temperature with less energy waste.
The 45 dB noise floor is quiet enough for concentration-based work like woodworking design or electronics assembly. The DREO app integrates with Siri, Alexa, and Google Home, and the sleep curve customization lets you program gradual temperature changes throughout the night. The true drainage-free system works in environments up to 90 percent humidity using a patented algorithm that senses moisture levels and adjusts evaporation rate, which is excellent for garages in humid climates where condensation would otherwise pool.
The 8,000 BTU capacity is simply too low for a large two-car garage or any space over about 250 square feet. In a larger garage, the unit will run continuously without ever reaching the set temperature, which wastes energy and wears out the compressor faster. The single-hose design still creates negative pressure in a sealed garage, but the effect is less severe at lower airflow volumes. The 150 square foot rated coverage area means you need to be realistic about what this unit can handle — it is a spot-cooler for a small garage area, not a whole-space solution.
What works
- Inverter compressor delivers faster cooling than many larger fixed-speed units
- DREO’s noise isolation keeps operation at a low 45 dB
- True drainage-free system works in up to 90% humidity
- Smart app with sleep curve customization for overnight use
What doesn’t
- 8,000 BTU is only suitable for small garages under 250 sq ft
- Single-hose design still creates negative pressure in sealed rooms
- Not powerful enough for whole-garage cooling in larger spaces
10. EUHOMY 14,000 BTU Portable AC
The EUHOMY 14,000 BTU portable AC offers both cooling and heating capability in a single-hose package, making it a versatile option for a garage that experiences both summer heat and winter chill. The 500 CFM airflow covers spaces up to 650 square feet, and the dehumidifier function removes up to 140 pints per day, which is exceptional for a unit in this tier. The inverter compressor provides smoother temperature regulation than non-inverter competitors, and the 7.9 CEER rating is reasonable for the price bracket.
The 5-in-1 modes cover cool, heat, dry, fan, and sleep, and the app and remote controls make operation convenient from across the garage. The sleep mode dims the display and reduces fan speed for quieter overnight operation. The window kit fits sliding windows from 19.6 to 50 inches with no professional installation required, which is helpful for renters who cannot make permanent wall modifications.
The single-hose design is the main weakness for a windowless garage, and owners have reported that the plastic window kit feels flimsy and does not seal tightly against the frame. The 47.2 dB noise level on low speed is higher than the quietest units in this guide, though still acceptable for a workshop environment. Some owners note that the sleep mode raises the set temperature by 4°F, which may result in a warmer garage than expected in the morning. The heat mode works well for taking the edge off a cold garage but is not sufficient as a primary heat source in freezing climates.
What works
- Integrated heating mode provides supplemental warmth in cool weather
- Dehumidifier removes up to 140 pints per day for damp garages
- Inverter compressor offers smoother temperature control
- App and remote control for convenient operation
What doesn’t
- Single-hose design limits effectiveness in sealed garages
- Plastic window kit feels flimsy and does not seal tightly
- Sleep mode raises set temperature by 4°F
11. Garvee 14,000 BTU Portable AC
The Garvee 14,000 BTU portable AC is the most accessible entry point for cooling a garage, offering a straightforward 3-in-1 system with cool, dehumidifier, and fan modes. The self-evaporating system eliminates manual draining in most conditions, and the washable filter traps dust from garage air to maintain performance. The 750 square foot coverage rating is generous for the price tier, and the 64°F to 90°F temperature range covers the typical cooling needs of a hot garage.
The sleep mode keeps operation below 48 dB, and the three fan speeds give you airflow control for different work activities. The compact design on smooth-rolling casters makes it easy to move around the garage for spot cooling at a workbench or near a parked vehicle. The adjustable window kit fits openings from 20.47 to 39.8 inches, and setup can be completed without special tools.
The single-hose design and lower build quality are the trade-offs for the budget-friendly price. Owners report intermittent clicking and clunking noises in addition to the normal operating sound, and the window adapter has significant gaps that let hot air back in unless you add extra foam sealing. The 48 dB noise level is higher than most competitors in this guide, and the lack of WiFi or app control means you cannot pre-cool the garage before heading out. For a small garage with a door that allows some natural air exchange, this unit provides workable cooling at a minimal investment.
What works
- 14,000 BTU provides usable cooling for garages up to 750 sq ft
- Self-evaporating system eliminates manual drainage
- Compact wheeled design for easy repositioning
- Washable filter traps dust from garage air
What doesn’t
- Single-hose design pulls hot air into sealed garages
- Intermittent clicking and clunking noise reported by owners
- Window adapter has gaps that require extra foam sealing
- No WiFi or app control for pre-cooling schedules
Hardware & Specs Guide
CEER and Inverter Efficiency
CEER stands for Combined Energy Efficiency Ratio and represents the total cooling output divided by total power input including standby. A higher CEER means lower electricity bills. Most portable ACs are required to meet a minimum CEER of 7.83 by the Department of Energy. Inverter models like the Whynter ARC-1230WN (12.3 CEER) and Gasbye (13.6 CEER) far exceed this minimum by using variable-speed compressors that adjust power output rather than cycling on and off. For a garage that runs the AC six to eight hours daily, every point of CEER matters — a unit with 12.0 CEER uses roughly 35 percent less energy than one at 8.0 CEER.
SACC versus ASHRAE BTU
The BTU number you see on the product page is usually the ASHRAE rating, which is measured in a lab without an exhaust hose. The SACC (Seasonally Adjusted Cooling Capacity) rating is more realistic because it factors in the heat that the exhaust hose adds back into the room. A typical 14,000 BTU ASHRAE unit may have an SACC of only 10,000 BTU. For garage sizing, use the SACC number to calculate coverage — divide the garage square footage by 20 to get the minimum SACC BTU needed. A 500 square foot garage needs at least 10,000 BTU SACC, which corresponds to roughly a 14,000 BTU ASHRAE model.
FAQ
Can I use a portable AC in a garage with no windows at all?
What happens if I use a single-hose AC in a sealed garage?
How do I vent a portable AC through a garage wall?
What BTU do I need for a two-car garage?
Can I use an extension cord for a portable AC in my garage?
Final Thoughts: The Verdict
For most garage owners without a window, the best ac for garage with no windows winner is the Whynter ARC-1230WN because its dual-hose inverter design eliminates the negative pressure problem that ruins performance in sealed spaces, and its self-evaporating drain system keeps your garage floor dry. If you need a higher BTU output for a larger or poorly insulated garage, grab the ZAFRO 16,000 BTU dual hose inverter. And for the absolute best energy efficiency with a three-year warranty, nothing beats the Gasbye 14,000 BTU with its 13.6 CEER rating.