How long does it take to install a window A/C unit? Less than 1 hour 100% Get Free Quotes Today! Question: How long does it take to install a window A/C unit? Top Answer (100% of 1 votes): Less than 1 hour. Get Free Quotes Today! Find Local Pros Free Window A/C Unit Installation Cost Estimates Related Questions How Often Should I Have My Central Air Conditioner Serviced?Top answer: Every year Can I have central air if I have baseboard heat?Top answer: In most cases Do central air conditioners need to be covered in the winter?Top answer: No Can central air run on natural gas?Top answer: In some cases Can central air be installed without a furnace?Top answer: Yes, always