Is 3-ton ac big enough for 2400 sq ft house?

If you have a lot of windows, are an older house, or live in a very hot city (like Las Vegas), you may need to cover 400 or even 300 square feet per ton. Then, to take into account the size of the house, we could divide the load or capacity by the floor area, but the numbers would be minuscule. For example, a 3000 square foot house with a 3 ton air conditioner would have 3 ÷ 3000 = 0.001 tons per square foot. By investing, we get a nicer number, 1000 square feet per ton.

Of the 167 zones, only 53 were less than 1000 square feet per ton. Only 20 areas were less than 700 square feet per ton. That means that only 12% of the areas in this group could have been close to having refrigeration equipment of the appropriate size according to the 400 to 600 square feet per ton rule. The average load of the 75 homes, as you can see in the graph, was about 1200 square feet per ton.

In those 63 homes, we selected 151 individual heating and cooling systems. As you can see, here the columns have been shifted to the left, indicating that the air conditioning equipment we chose was larger than the loads. That's why the average capacity of the systems we selected was 856 square feet per ton, making our average capacity 28% higher than the average refrigeration load (1192 square feet per ton). The design of an air conditioning system starts with the right size.

Look at the number of square feet per ton you can see if you're in the stadium. If the number is less than 1000 square feet per ton for newer homes, the number is wrong or the house isn't as efficient as it should be. With a 1-ton Midea modular vibrator (basically a minisplit in a can) mounted on the window of the office loft high up the stairs of my approximately 2400 foot vintage house from the 1920s, while all the interior doors remain open, it covers 100% of my 1% cooling load (1% local temperature container = 83°F) at an average indoor temperature of the mid-70s F. That's a ratio of tons to 2400 feet under design conditions. Without the window unit turned on, running the ridiculously oversized central air with 5-ton ducts, the duty cycle never exceeds ~ 50%, even when outdoor temperatures are around 90°F (like now), implying a load ratio of one ton per 1000 feet at outdoor temperatures of 10 °F or more ABOVE the design temperature of 1%.

If you have a 1200 square foot home, you'll need a two-ton unit. A 2,400-square-foot house would need a four-ton unit. Once again, there are 2.5 ton and 3.5 ton units in case your square footage isn't perfect for a two- or three-ton unit, for example. One of those variables is insulation, and another complete set of variables is the type and number of windows in the space, the number of floors in your house, the type of construction, etc.

In a 3000 square foot house, for example, the installer using the general rule could place 6 tons of capacity.