The Toshiba RAC-WK0512CMRU is a basic window-mount A/C intended for small rooms, with an advertised coverage of 150 ft² (14 m²). It's a simple unit with a mechanical thermostat and physical knobs to adjust the desired cooling and fan speeds.
Our Verdict
The Toshiba RAC-WK0512CMRU is only a satisfactory option for large rooms. Its low capacity means it'll struggle to cool spaces like an open-concept living area or a larger playroom. Its compressor also runs constantly in larger spaces. This gives it ample time to draw in ambient moisture and maintain consistently low humidity levels, but unfortunately, this constant operation places unnecessary wear and tear on its components. It thankfully doesn't consume much power when maintaining a consistent temperature, and it's decently quiet, too, with operating noise low enough to be masked by music or television.
Low overall power consumption.
Maintains consistent temperature and humidity levels as unit runs continuously in larger spaces.
No remote control, so you'll need to change settings on the unit itself.
Continuous running can put more wear and tear on components.
Not suited to cooling larger spaces.
The Toshiba RAC-WK0512CMRU is a great option for use in small rooms. It's a relatively compact unit that fits in smaller windows and can be stowed in a closet when not in use. It's effective at maintaining a desired room temperature and a reasonable humidity level, ensuring you won't wake up feeling overly clammy. While its limited fan speed adjustment range makes it a little louder than other alternatives at its lowest setting, it's still pretty quiet overall, similar to low traffic from a street outside.
Cooling capacity is well-suited to smaller rooms.
Compact, lightweight design makes it easy to install.
Low overall power consumption.
Louder than comparable window models at lowest setting due to high fan speed.
No remote control, so you'll need to change settings on the unit itself.
The Toshiba RAC-WK0512CMRU's cooling capacity is okay. It's more than capable of cooling smaller offices or bedrooms, but it'll struggle to cool anything larger than that within a reasonable span of time.
Cooling capacity is well-suited to smaller rooms.
Not suited to cooling larger spaces.
The Toshiba RAC-WK0512CMRU's overall efficiency is very good. It's a fairly low-output unit, so it isn't ideal for cooling larger spaces like living rooms or large playrooms within a reasonable timeframe. That said, its power draw is impressively low. Despite using a less sophisticated fixed-speed compressor and having to constantly cycle it on and off to maintain the desired temperature, that low power draw helps keep overall energy consumption reasonably low.
Low overall power consumption.
The Toshiba RAC-WK0512CMRU does an excellent job of maintaining ambient conditions. Its low capacity means its compressor runs almost continuously to maintain the desired temperature, giving it time to pull moisture from the air and resulting in very stable ambient perceived humidity levels. This constant running will also subject its components to greater wear and tear, potentially reducing the unit's lifespan.
Maintains consistent temperature and humidity levels as unit runs continuously in larger spaces.
The Toshiba RAC-WK0512CMRU is decently quiet. It offers only two fan speed settings and has somewhat low operating noise, which can be mostly masked by watching TV or listening to music. That said, its limited adjustment range means its lowest fan speed is a little louder than some alternatives, which could be disruptive if you're running it while you sleep.
Louder than comparable window models at lowest setting due to high fan speed.
The Toshiba RAC-WK0512CMRU is a very compact air conditioner. It's considerably narrower and shallower than higher-capacity window units, which makes it both easier to stow away in the winter and better suited to fitting in smaller windows. It's also lightweight, making solo installation considerably easier than with a higher-capacity unit.
Compact, lightweight design makes it easy to install.
Performance Usages
Changelog
- Updated Sep 15, 2026: We've updated this review to Test Bench 1.1. which changes how we measure and score performance as a whole. The Capacity, Efficiency When Cooling, Efficiency When Maintaining Temperature, Temperature Stability, and Humidity Stability boxes have been updated. If you're looking for further details, see the Changelog.
- Updated Jun 06, 2025: Review published.
Check Price
Differences Between Sizes And Variants
The Toshiba RAC-WK0512CMRU is only available in one color variant: 'White'. Those interested can see the first product label, as well as the second one.
Let us know in the comments if you come across another variant of this air conditioner.
Popular Air Conditioner Comparisons
The Toshiba RAC-WK0512CMRU is a cheap, simple window-mounted A/C designed for small spaces. It's an entry-level model in Toshiba's lineup of window A/Cs, with a lower advertised capacity of 5,000 BTU/hr versus the slightly larger and pricier Toshiba RAC-WK0612CRRU. It's a bit of a standout in the 5,000 BTU class, being a little quieter and better at minimizing temperature swings compared to the Frigidaire FFRA051WAE.
If you're looking for alternatives, see our recommendations for the best small room air conditioners, the best air conditioners for bedrooms, and the best window air conditioners.
The Frigidaire FHWC054TE1 and the Toshiba RAC-WK0512CMRU are both compact window A/Cs with similar overall capacity and efficiency. Broadly speaking, though, the Frigidaire offers a slightly more premium user experience, with a remote control and an LED display for setting the desired temperature. Meanwhile, the Toshiba does a better job of maintaining your desired temperature and minimizing humidity fluctuations while running.
The Toshiba RAC-WK0512CMRU and the Frigidaire FFRA051WAE are very similarly designed entry-level window A/Cs. Despite the Frigidaire's on-paper advantage in advertised coverage, both units deliver all but identical cooling performance. The Toshiba operates a little more quietly and experiences slightly lower swings in ambient humidity once it reaches your desired temperature.
The GE AHEF06BC and Toshiba RAC-WK0512CMRU each have their strengths. The Toshiba is the better option for smaller rooms. Thanks to its shorter, more frequent compressor cycling, it does a much better job of maintaining the desired temperature and perceived ambient temperature levels. That said, the GE offers slightly greater cooling capacity and will chill the air in most rooms a little faster. It also provides a slightly more upmarket user experience, with a digital control scheme that allows you to input your desired temperature with more finesse, not to mention an included remote control.
The Toshiba RAC-WK0612CRRU and Toshiba RAC-WK0512CMRU are both window-mounted ACs with slightly different capacities. The WK0612CRRU is the fractionally larger, pricier option with an advertised capacity of 6,000 BTU/hr, compared to the WK0512CMRU's 5,000 BTU/hr. This gap in capacity isn't sufficient to run the risk of cooling an equivalently sized room too quickly and causing a buildup of humidity. The WK0612CRRU's somewhat greater capacity also means its compressor cycles less rapidly, resulting in larger, more frequent swings in humidity and temperature. On the upside, the WK0612CRRU, unlike the WK0512CMRU, has a digital thermometer that lets you set the desired temperature and comes with a remote control to operate the unit from a distance.
Test Results
It's worth noting that this unit's height with the window bracket installed is 34 cm (13.4"). The shorter height measurement provided is to account for storing the unit or for wall installations.
The Toshiba RAC-WK0512CMRU has adequate overall cooling capacity. It's well-suited to cooling smaller rooms like an office or bedroom, but it'll struggle to cool bigger living spaces in a reasonable amount of time.
This is an impressively efficient unit. It has a low power draw, but it'll have to run longer than higher-capacity units to achieve your desired temperature.
Despite being a non-inverter unit and having to cycle its compressor to maintain the desired temperature, its low power consumption makes it relatively efficient at maintaining that temperature.
This A/C does a fantastic job of maintaining a stable temperature level once the setpoint is reached. Its compressor cycles rapidly enough in standard operation as not to generate any big swings in ambient temperature.
This unit does an excellent job of maintaining humidity levels. In standard operating conditions, its compressor cycles on and off rapidly to maintain the desired temperature. These cycles are too rapid to cause moisture to re-evaporate from the unit's coils, keeping the air in your room consistently cool and dry, so humidity will remain at a comfortable level even in areas where the moisture level of the surrounding air is already quite high.
