Great article! But I am still doubting myself. Located in central California where we get some heat 90’s-100’s most of the summer. I have a 20×30 detached garage with 8′ ceilings. The ceiling and walls are insulated. The 12×7 garage door is insulated. There are (3) 4×4 Windows and (2) door standard entry doors. The building gets sun for most of the day. No stove or oven, but there are several arcade games and pinball machines that generate some heat, though not nearly as much as an oven. I was thinking a 24,000 btu single zone minisplit? Or would 18,000 be sufficient. Would like to keep the building at 70-72 in the summer. Reply As far as I can tell, based on square footage alone I would be looking for a 5000 btu unit, but I am wondering if 6000 might be better given the location of the room and those additional factors. I definitely do not want to cause moisture issues by getting too big a unit, but do not want to undersize and have a unit not work either. You’ll find below a pretty handy chart that will help you pinpoint the right model. You’ll notice that room size and heat load are the two variables within this chart. Step one is simply figure out the room size in square feet of the room you would like to keep cool. Next, figure out the amount of heat or "heat load" that the room receives. For example, if the room has a lot of windows or is next to a kitchen, that room would probably have a high heat load. The source of sound in portable AC units is compressor and airflow. For higher BTU’s the compressor has to work harder and the airflow is higher; that’s why portable air conditioners with higher BTUs. You can see that very well in our article about the quietest portable air conditioners. Reply

Hello Annabelle, you’re looking for about a 6,000-7,000 BTU unit. Unfortunately, the smallest portable AC unit has 8,000 BTU ASHRAE.your best choice is 6,000 b t u for each bedroom and a 12,000 b t u for the living room kitchen and dining room Hello Bob, the space-wise structure you have there is quite complex. You should probably talk with an HVAC installation expert who can also recommend the best mini split to use, in addition to AC capacity (BTU). We have 1000s of experienced HVAC expert across the US, you can use this link to get an HVAC expert in your area to help you out. They’ll certainly know how to calculate that ceiling slope. Reply The wall ac just died since it is 13 years old and landlord isn’t going to replace it, so, it is up to me, but all i see are window ac units and 5,000btu is too big for the wall opening. Reply It is a 137 square foot bedroom with 8 foot ceilings. There is also an additional raised platform space that is about 4 feet high from the platform to the ceiling and is 135 inches wide and 27 inches deep. Don’t want to use the BTU calculator above? No worries. Here’s a reference chart that will give you a pretty good idea of how many BTU’s you will need, based on the total size of your room. BTU Chart Based on Room Size

Hello Selena, 20,000 BTU unit has the right size, and will deal both with hot and humid indoor air. However, 15,000+ BTU units require 220V voltage. If you will have to upgrade your electrical grid just for that, it might make more sense to buy an additional 12,000 BTU or 15,000 BTU unit. Together, they will also create a more homogenous cooling (without hot spots); this might be a problem with 1 20,000 BTU unit if it has a low airflow (measuring in CFM). ReplyPlease be aware that we currently cannot arrange for delivery of this product to the following postcodes: AB, FK, HS, IV, KA, KW, PA, PH, ZE, LL58-LL78, IM, TR, BT, PO30-41. The cooling capacity of the AC-5670 Air Conditioner is 7000 BTU and 2.1 kW, making the air conditioner suitable for a room up to 60 m³. The air flow produced by the air conditioner is up to 320 m³ / h. You can of course set the temperature yourself from 16⁰C to 31⁰C. Because the air conditioner has three options, you can also use the air conditioning to dehumidify the air or as a fan. Enjoy coolness when you go to sleep. With the handy timer function you can leave the air conditioning on for a while, while you fall asleep in a cool room. The air conditioning then switches itself off after a considerable time. My question relates to how the kitchen bump up intersects with the common advice that if you oversize your unit, then it can lead to short cycles that leave you with humidity and wear out the equipment. No article online seems to makes clear how much wiggle room you have before that might happen, and often it’s simultaneously encouraged to go one higher than you need. Hence this 4000BTU kitchen bump comes to mind and whether that’s enough to amount to a harmful oversize during the majority time the kitchen is not used.

sounds like your electrical supply for both appliances are connected together. Use a dedicated circuit for your a/c. I am living in the Caribbean, my entire house is 30 * 20 ft, one bed room is 11 * 9 ft floor to ceiling throughout the building is 9 ft. The house is elevated and has wooden floors now can you advise say if i should buy the 4000 BTU for my room or splurge and buy the 12,000/14,000 BTU for the entire house?

Hello, I have a tiny 100 sq ft room in the garage that I am trying to turn into a hair salon. Do they make a mini split small enough for a/c and heat or what is my best option for that small of space? Thank you Reply Hello Michael, 16×16 bedroom has a total area of 256 sq ft. That means a 5,000-6,000 BTU would be enough. You are right; the 15,000 BTU unit is definitely an overkill for a single room. Conservative choice would be the old Frigidaire FFRA051WAE 5,000 BTU. However, given that you have problems with high humidity, a stronger Frigidaire FFRE0833U1 8,000 BTU makes sense (it comes with 1.7 pints per hour dehumidification; it can draw more than 40 pints of water per day). Hope this helps. Reply For smaller spaces (example: camping air conditioners for tents), you can use portable battery-powered AC units.

The living room unit is 6,500 BTU and the bedroom unit is 6,000 BTU. I use them only for those rooms. The BTUs are more than adequate for the spaces, but the units are too old to work properly and need to be replaced. Trying to figure out what I’d need for my enclosed patio. It has 2 (one exterior) doors, 6 windows, and 2 skylights. It’s 20ft by 15ft with 10 ft ceilings. There are 3 oaks but midday does get a lot of sun through the skylights. Live in Savannah, GA. Reply Hello there, you’re right, you have quite a complex situation and therefore the BTU estimate is not a piece of cake. 5,000 BTU unit might be adequate but with so many variables the safer option would be 6,000 BTU (San Diego, raised platform space, and so on). Hope this helps. Reply

Particularly in the case of heat pumps and air conditioners, the cooling capacity of appliances is often given in BTU. Therefore, BTU is defined as how much heat energy is needed to raise one British pound of water by 1 degree Fahrenheit.