We are working on an extreme fixer upper, 130 year old farm house. Installed a new oil furnace and 3 ton central air with a conventional condensing unit.

Can anyone point me in the right direction to obtain information and possibly dimensions to properly size a water to freon heat exchanger to replace the freon to air condenser on the present compressor unit?

I suppose that buying one already made is OK too. I'm wired up backwards so that my default inclination is to design and build my own. I can be talked out of it, but there is that satisfaction of knowing you built it with your own hands.

I have welding and machining capabilities. I'll let a professional HVAC tech handle removal and recharge of freon while the exchanger is being installed.

There are three wells on the property, so ground source water shouldn't be a problem.