I have my new EKO 40 outside in my dedicated boiler shack 130' from the house. My 490 gallon pressurized insulated storage tank that I bought from new horizons is located in my basement next to my forced air furnace. My wife and I have very inconsistent schedules so may not be able to avoid antifreeze for freeze projection. I know antifreeze should be the last choice but lets assume its the most reasonable option due to my situation. I am having a hard time swallowing the price of 250 gallons of antifreeze. I am contemplating on using a water to water plate exchanger to separate the inside storage tank from the boiler. I would then use antifreeze only on the outside boiler side which would probably less than 50 gallons of water. My concern is efficiency of the plate exchanger and the negative impact that this would have on the capability of my system.