Talk to your dad. Hire one of those HVAC techs and get an Abatement Technologies portable. We've done retirement apts with the portable and it does a great job on smaller systems. Its easier to work with on above ground level work than the gas fired.If I got the training and man power, I'd jump into this.... A lot of hack work done here... I'd have a nice referral network as I know a lot of refrigeration guys...