have to replace evap coil on this self contained cooler. It blows cold air on patient at doctors office. athe compressor has 404 and 507 stamped on it. it currently runs on 507. we have a full jug of 404. I hate to buy a full jug of 507 for 33 ozs. the factory subcontractor says it is ok.wasnt sure
Both gases use the same tev element for low temp. For medium they are different. For example: a sporlan tev valve will use a "PC" charge for medium temp 507 and an "SC" charge for medium temp 404a. Other than that it will be fine.