If new A/C equipment is needed, then choosing the right equipment for the application is part of the process as well as duct design and installation parameters. High efficiency equipment is always a good choice; however budget limitations and payback to investment are factors to consider, your budget should also include post installation service and warranty. Be sure to check out the company you choose to install your comfort system, the Arizona Registrar Of Contractors and the Better Business Bureau are two excellent resources for that purpose here in Arizona. Make sure your contractor performs a proper job-site survey prior to start of the work, checking all parameters required for proper installation. Upon completion of the comfort air conditioning system installation, all equipment should be tested and all readings confirmed to be within operational parameters. A commissioning checklist should be filled out with recorded readings, procedures practiced, and system condition to give you the actual system performance and for verification of proper procedures. Air Conditioning Houston TXThis message has been edited. Last edited by: adah1256,