With the wide range of consumer electronic brands in the market today, little known, good quality manufacturers may struggle to get a following of their own. This may be one of the reasons why a company like Keystone may not be as well known, but this is not in any way to imply that it\u2019s not a company that pushes out sub standard products. The Keystone 450 Sq Ft wall air conditioner for example has been known to be a favourite among some American buyers, especially those who are in the market for the best air conditioner for sliding window. Make sure to get to the end of this review to find out what it has to offer.\r\nWhy We Like It - Keystone 450 sq ft\r\nThe Keystone 450 Sq Ft Casement window air conditioner is a perfect pick for anyone that\u2019s looking for a unit that\u2019s got an easy to use control panel, and also allows for quick window installation. It\u2019s decent 10000 BTU is great for a 450 Square ft area, so if this sounds like your room, go ahead and see what it\u2019s got to offer.\r\n\r\nPerformance\r\nWith a 10000 BTU rating, the Keystone window air conditioner is easily capable of servicing a room that\u2019s up to about 450 square feet in size. The AC unit boasts an airflow rate of 200 cubic feet per minute, and a 4 directional top louvre that\u2019s essential for airflow control. Based on its looks, it would be very easy to confuse it with the Frigidaire 10000 btu air conditioner, as they\u2019re both suited for a vertical window, and have a top segment that\u2019s separated from the larger bottom half. The window air conditioner is also capable of dehumidification, as it is able to remove up to 1.1 litres of moisture from the air per hour.\r\nEnergy Efficiency\r\nThe Keystone 10000 BTU window air conditioner does not really have an Energy Star rating, but what it does have is an energy saver mode, which you can activate if you would want it to not consume a lot of power as it would on a normal setting. It\u2019s got an Energy Efficiency Ratio of 10, which makes the Frigidaire 8000 BTU air conditioner a better pick since it\u2019s got a higher ratio of 13. Just so you know, the higher the ratio, the less you\u2019ll need to spend on energy costs.\r\nFiltration\r\nMost if not all window and wall air conditioners have a filter included inside that\u2019s key for ensuring that no unwanted substances get circulated through the air in the room that the AC unit is in. This is important so as to ensure that the cool air that is disseminated is clean and harmless. The Keystone AC has got a slide-in, slide-out, washable air filter that\u2019s easy to remove, and unlike the Honeywell MN10CESWW, it features a clean filter alert that lets you know when it\u2019s time to clean or replace it.\r\nDurability\r\nYou should be able to spend at least a solid year with the Keystone 10000 BTU AC working in perfect condition before it starts developing problems, and if it does within this period, you shouldn\u2019t hesitate to reach out to the customer care team from Keystone and let them know of your predicament. This is because the unit is backed by a 1 year warranty that covers both parts and labour.\r\nValue\r\nUnfortunately, the Keystone 450 Sq Ft doesn\u2019t come with a remote control, so you\u2019ll have to always walk to it to make any adjustments to the settings. The LED display allows you to see the current settings, and if you so wish, you can switch into special modes like sleep mode where the unit increases the temperature gradually so as to maximize energy savings.\r\nKeystone 450 sq ft Wrap Up\r\nThe brand Keystone may not be as popular as some other household names, but it is still a worthwhile option to look into. Go ahead and hop over to their Amazon page to see what first time buyers had to say about their products.