Keystone Air Conditioners not only cool a room, but also remove unwanted moisture so your room won\u2019t feel as hot in the humid summer. And as long as you\u2019re not standing directly beside it it\u2019s quiet enough to make sure you remain undisturbed. We consider it a best through the wall air conditioner because of its certifications and efficiency features.\r\n\r\nWhy We Like It - Keystone Air Conditioner\r\nThe Keystone Air Conditioner is an excellent choice of air conditioner if you\u2019re looking to cool a medium-sized room or one on the precipice of being a large room. It\u2019s excellent EER Rating has earned it an Energy Star certification, and although it\u2019s on the heavy side you\u2019ll be happy to know that it\u2019s also more stable.\r\n\r\nPerformance\r\nThe Keystone Air Conditioner boasts an impressive cooling power of about 12,000 BTU\u2019s. This is more than enough to cool a room of about 550 square feet. And like its cousin, the KSTAT10-2C Keystone Air Conditioner, you can get different models with more or less BTU\u2019s if you desire. It can also remove up to 2.5 pints per hour of moisture out of the air too! Great for those hot and humid summer days.\r\nEnergy Efficiency\r\nWith an Energy Efficiency Rating (EER) of 10.5 it\u2019s easy to see why the unit has earned the strict Energy Star Certification from the EPA. See the Friedrich Wall Air Conditioner if Energy Star Certification is important to you. Unfortunately, there\u2019s no word on if the Keystone Air Conditioner is also UL Listed which would have been a nice extra certification to have.\r\nFiltration\r\nIt\u2019s cumbersome to clean the filter on almost all in-wall air conditioners, and this Keystone Air Conditioner is no different. However, at the very least it\u2019s a front-access filter. Simply pull it out and clean it, and slide it back into place. And unlike other air conditioners that ask you to rinse the filter, this air conditioner makes a point of saying you can vacuum the filter instead if you so please.\r\nDurability\r\nAt 76 pounds, the unit is a little on the heavy side when it comes to in-wall air conditioners. But at least this means there will be less rattling noise. And it\u2019s still lighter than the Emerson Air Conditioner. But speaking of sound, the Keystone Air Conditioner is rated at 56.5dB. For reference, human conversation ranks at 60dB. So as long as you aren\u2019t standing right next to it, the unit can operate without disturbing you.\r\nValue\r\nSome conveniences included are a remote control so you won\u2019t have to walk across the room to adjust fan speeds. The Auto Restart function is another handy feature that allows the unit to reboot itself in case of a power outage. And if you like to take customer reviews into account when making a purchase, the unit has a 4\/5 star rating based on 533 reviews over on Amazon.\r\nKeystone Air Conditioner Wrap Up\r\nKeystone produces fine in-wall air conditioners, and this model is no different. It\u2019s cumbersome to clean the filter, but that\u2019s a theme across all in-wall air conditioners so we\u2019re not going to penalize it too much. Think about the units programmable modes and certifications and quietness and you\u2019ll realize cleaning a filter isn\u2019t so bad.