Air conditioner BTU requirements: this article provides an air conditioner BTU chart shows how to choose a room air conditioner for window or through-wall mounting. We provide room air conditioner or window air conditioner BTU sizing & choice charts. We also show how to actually calculate how much BTU cooling capacity you need based on building area or square feet, and we warn about dehumidification problems if you buy an air conditioner that is too big for the space you are cooling. Portable, window, or through-wall air conditioners are typically described by their manufacturer as suited for: The table below gives recommended air conditioning BTU's necessary to cool a single room. The data in the table assumes that the ceiling over the room is insulated and that the room is not over or is not itself a special heat-producing area such as a kitchen or boiler room. Table 1: Base BTUs - Recommended Air Conditioner BTUs Calculating BTU Requirements: instead of using the table above, and particularly where factors may make the table inadequate (examples are given just below) you may want to CALCULATE the BTU COOLING REQUIREMENT using the procedure given below in this article.

Ceiling height variations: BTU capacity tables for air conditioner selection typically assume typical 8 foot ceiling heights in residential spaces. If your ceilings are significantly higher, say 14 feet or more, you may want to use the next larger room area size when selecting the BTUh capacity needed for your air conditioner, particularly if your building is located in a hot climate with higher heating loads.charge my ac unit my car Building heat gain rate variations: in locations of high heat gain or high solar gain such as a significant exposure to direct sunlight or many sun-facing windows, or for buildings with little insulation, you may need to select a higher-capacity air conditioner than given by the table.ac unit isn't runningof a typical home can be cooled per ton of cooling capacity: that is, one ton (or 12,000 btuh) of air conditioning can cool about 500 sq.ft. how to install an air conditioner wall unit

But the real answer is, it depends. Some of the factors that affect the ability of an air conditioner to cool a space need to be considered besides just the number of square feet. These include at least the following questions about air conditioning load and cooling requirements: Watch out: Do not buy an air conditioner which is oversized (too many BTUh) for the area you need to cool. You may think that bigger is better, but not in the case To make a room comfortable the air conditioner needs to both cool the room air AND dehumidify the room air. If the air conditioner is too large for the space to be cooled, the temperature will drop quickly and the A/C unit will shut off before the air has become adequately dry. The room will be either too cold or too humid for comfort. More detail about how to diagnose and cure an air conditioner that is not dehumidifying can be found at DEHUMIDIFICATION PROBLEMS Continue reading at BTU SIZING FAQS for AIR CONDITIONERS or select a topic from the More Reading links or topic ARTICLE INDEX shown below.

Or see DEHUMIDIFICATION PROBLEMS Or see PORTABLE AIR CONDITIONER BTU CHART for portable room air conditioner BTU sizing advice.Window air conditioners are cost-effective and can provide relief quickly. Window-mounted air conditioning units are a cost-effective alternative to central air when renting or when installing central air is cost-prohibitive or otherwise inconvenient. A window air conditioner can also provide immediate relief on a hot day if central air installation is in your future plans but not yet a reality. Make sure that your window unit is installed properly, especially when it has the potential to fall from several stories up. Installing these units is not difficult, but there are some common installation mistakes you should avoid. Sizing The most common problem when installing a window air conditioner is often simply installing a unit of the wrong size. To operate efficiently and effectively, a window air conditioner should have a cooling capacity of 20 British thermal units per square foot of space in the room.

A unit that is operating in a room with high ceilings or in direct sunlight may need to have a slightly larger capacity, but it is important to understand that bigger is not always better. An oversized window unit running in a small room will not cool better than a smaller unit. A smaller unit running for a longer period of time is more efficient than a larger unit continually turning itself on and off. The most practical and economical way to stay cool is to make sure the window unit is the right size for the space. Weight Distribution When installing a window air conditioner, many people simply open the window, slide the air conditioner into it, and close the window as far as it will go. This installation method forces the window itself and the window sash to bear the weight of the air conditioning unit and could potentially damage the window. This is especially true with vinyl replacement windows, which can be easily broken or warped by a heavy air conditioner. When installing your unit, take the time to attach a strip of wood to the outside of the house just underneath the window to help support and distribute the air conditioner’s weight.

If the unit is extremely heavy, use L-brackets to install a shelf for it to sit on. Make sure the shelf is constructed of expanded metal or another porous material so it does not block the water draining out of the unit. Keep It Level Air conditioners remove water from the air as part of the cooling process, much like a dehumidifier. This causes condensation to collect inside the unit and drain from a hole in the back. Many people incorrectly believe that window air conditioners should be installed at an angle to help facilitate this drainage. In reality, air conditioners are built with gutters and channels that direct the water where it needs to go when the unit is level. Tipping the unit can direct the water away from the proper channels and into parts of the air conditioner where it should not be. This may actually make it more difficult for the unit to drain. Always make sure that the air conditioner is level when it is installed and allow the internal channels to direct the condensation to the drain on their own.