What Size Air Conditioner Should You Have in a 2000 Square Foot House?

Window units are the most common form of zone specific cooling.

Sizing an air conditioning (AC) unit for a 2,000 square foot house requires more than just the basic square footage of the living area. A properly sized AC unit takes into account the use of specific rooms, such as bathrooms and kitchens, and the type of cooling desired, such as zone cooling or general climate control.

Measuring Square Footage

A realtor may list a house as 2,000 square feet based upon the areas of the house determined livable. Determining the square footage for heating and cooling follows slightly different methods. The key thing to remember is to individually measure each room that is or will be impacted by the AC unit. Multiply the length of the room by the width of the room. Do not measure rooms that are sealed off from the unit or that will not be cooled by the unit, such as basements, attics or closets. Keep each room's square footage separate.

Converting Square Footage to BTUs

British Thermal Units (BTUs) are the measurement of how much heat is pulled from the air by an air conditioner. Converting BTUs for large rooms or general measurements requires multiplying the total square footage of the room or area by 25. A 2,000 square foot area would equate to 50,000 BTUs. However, smaller rooms have much different needs. A 100 to 150 square foot room needs 5,000 BTUs. A 150 to 250 square foot room needs 6,000 BTUs. A 250 to 350 square foot area needs 7,000 BTUs. Add 4,000 BTUs for kitchens and 1,000 BTUs for laundry, bathrooms or other warm and humid rooms that will be connected to the system.

Split System Sizing

Split-systems, more commonly known as central air conditioning, are measured by tonnage. Split-systems provide overall climate control for the whole area. The initial costs for installation can be very high if ductwork and electrical wiring installation is necessary. Monthly costs for a properly sized unit have the highest potential for savings compared to ductless or window units. To convert BTUs to tonnage, divide the total house BTUs by 12,000. For the 2,000 square foot house, a total of 50,000 BTUs minimum equates to 4.1 tons. A 4.5 ton AC unit would be the bare minimum size needed.

Ductless and Window Units

Ductless systems and window units may be more ideal. The systems offer specific zone control. A 2,000 square foot structure may only have one room that is used frequently. The other rooms may be used only on rare occasions. To cool only one zone, a ductless unit or window unit can be cheaply installed. The smaller unit does not hold the cooling capacity of a split-system but is more than capable of cooling a specific zone. Installation is cheaper and monthly costs can be cheaper if limited zones are cooled. Ductless and window units are measured in BTUs.

References

• Go Ductless: Help
• Alpine Home Air: Selecting Air Conditioner Size
• Spot Cooling: Calculating Server Room Heat Loads