Heating and cooling
Window
A window A/C unit has the lowest price tag with a range of $340-$1150. Units require no ductwork and can be installed with a DIY installation kit which the manufacturer typically includes with the product.
| Pros | Cons |
| Low Price Easy Installation (Possible DIY) | Blocks Window(s) Unattractive |
Central
In a central A/C system cool air is delivered throughout interior zones from an exterior condenser/compressor through a series of ducts, usually concealed within walls and ceilings.
A central A/C system is typically the most expensive option, ranging from $2650-$15,000. Due to the complexity of the project a professional contractor, and possibly an electrical subcontractor, is required.
| Pros | Cons |
| Most Efficient Hidden Interior Components | Most Expensive Option Contractor(s) Required Wall Penetrations Required |
Ductless
Ductless A/C systems are used to retrofit homes that were not originally built with a central air conditioning system. Overall cost may range from $1800-$7000 depending on the work required. Ductless systems also require a professional contractor, and possibly and an electrical subcontractor.
| Pros | Cons |
| System Also Includes Heat Unobtrusive Equipment | Requires Some Wall Penetrations May Require Electrical Upgrades Contractor(s) Required |
BTUs
The cooling capacity of an A/C unit is measured in British Thermal Units (BTUs), which is a traditional unit of work equal to 1055.06 joules. It is the amount of work needed to raise the temperature of 1 pound of water by 1 degree Fahrenheit. Energy Star, a division of the Environmental Protection Agency, recommends installing a unit with the appropriate amount of BTU’s for the zone square footage to obtain the most effective cooling possible:
Square Feet to be Cooled BTUs Recommended
100 up to 150 5,000
250 up to 300 7,000
400 up to 450 10,000
700 up to 1,000 18,000
1,000 up to 1,200 21,000
1,500 up to 2,000 30,000
2,000 up to 2,500 34,000