Gas and Oil Home Heating Furnaces - relocating HVAC condensor unit

We are replacing a 24 yr old heat/cooloing unit. We want to move the condensor unit about 40 feet. Contractor claims that adding that much refrigerant line to the condensor will jeapordize efficiency. Do you agree?

Your contractor is right there is an efficency loss. I would say only a few percent though. Long lineset runs can be made but you need to follow the manufactors recommendations.The sizes of the lines usally need to be increased to correct for the resistance created by the length.If you have the manufactors name and the size of your unit we could help you size it.

Longer regrigerant lines will decrease performance to a degree but I do believe (if it's done right) that you can get a satisfactory installation. I'm assuming that you meant that your new condensing unit would be 40 feet from your furnace? That's not really that far, we did it all the time. But (here comes the but) always be aware of warranty considerations on your new unit. Your contractor should contact the mfg anytime there is a question about lengths of ref lines. (he probably already has a chart and many mfg's have recomendations in their installation instructions that come with the unit.) As a contractor I set equipment many time with 75' to 100' of refrigerant lines, used mfg recomendations (which included resizing the lines) and the warranty requirements were met and the customer's needs were met too.
Good luck!