Calculate the square footage of your home. You may be able to find the square footage by asking the landlord, consulting a deed of sale or asking the tax assessor's office. If those don't get you the answer, multiply the length and width of each room to get the square footage. Add the figures to get a rough estimate of square footage.
Count the number of windows in your home. Windows will affect the rate of power output, or BTUs, that your Trane air conditioner should have. Windows are a point of weakness with little insulation. Cold air can escape and heat can enter through them.
Log onto the Trane website and select the system customizer. This will prompt you with a dialogue box to enter your square footage, ZIP code, number of windows and a few other details. Fill in all required fields and click "Submit". The system customizer will perform the calculations and suggest the best-sized air conditioner for your home and your needs.
- You can contact a Trane dealer or technician to assist you with home air conditioner sizing if you're having trouble finding the system right for you.