HVAC Load Calculator

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When buying a new air conditioner, choosing one with the right capacity for your space is a crucial factor. There are two main elements to consider for the new equipment: temperature and humidity. If the new A/C is too small for the area that needs to be cooled, the A/C will struggle to reach the desired temperature and, as for the humidity, it will remove much more humidity than what is necessary. All this translates to higher energy costs and loss of comfort. “However, an oversized air conditioner is actually less effective — and wastes energy at the same time. Air conditioners remove both heat and humidity from the air. If the unit is too large, it will cool the room quickly, but only remove some of the humidity. This leaves the room with a damp, clammy feeling. A properly sized unit will remove humidity effectively as it cools.

Here are the steps that will help you figure out which unit size is best for your cooling needs:

1- Identify the Region of the US in which you are located according to the provided map.
2- Determine the square footage of the area to be cooled.
3- Determine the height of the rooms to be cooled, a standard height is 8 feet.
4- Insulation is a very important aspect for your calculation load, we give you five options to choose from, being the US standard the average.
5- Sun exposure: refers to the amount of area that is exposed towards the sun. There are partition walls inside the home as well as sun exposed walls, so the tool we provide has set options to guide you in choosing the correct exposure in regards to the area you wish to have cooled: shaded/or interior, average or strong. This setting will influence a lot the final answer.
6- Number of windows in your area is another aspect to consider, since glass has a lesser insulation grade than a wall.
7- Since temperature and humidity need to be controlled, air tightness for the doors and windows is a matter to look into. What kind of windows do you have installed?
8- Knowing if you are trying to cool a glass sunroom or not is a huge deal. As explained before, glass has a lower insulation factor than other materials, so we need to know if the area to be treated is a glass sunroom or not.
9- Another factor to consider are the number of people that are normally present in the room. This will impact the calculation load.
10- The type of illumination that is used in a room is a source of heat, especially incandescent light bulbs are installed.
11- Kitchen appliances that generate heat, such as the stove, refrigerator, microwave, etc. Knowing if we are including a kitchen in the load calculation is a must.
12- Finally, we need to include any additional equipment that will generate heat and input its capacity in watts.
13- Once everything has been entered the final step is to press the FILTER RESULTS button.

For example: If we are located in Region #1, with a square footage of 400 and height of 8 feet, with US Standard Insulation Grade, and average exposure to the sun, and average amount of windows, average design in air tightness, no glass sunroom, 2 or less occupants, 3 led light bulbs, no kitchen and no additional devices, the result recommendation is a 12,000 BTU A/C. Now the next step would be choosing the efficiency (SEER).