Ok,
A/c & dehumidifier compressors need oil for lubrication. Refrigeration circuits of which the compressor is a part are hermetically sealed. The compressor is charged with oil at the factory. Unless there is a very serious refrigerant leak oil does not leave the ref. circuit and therefor it isn't necessary to add oil. Dehumidifier compressors are the same as a/c compressors.
Pumping air there will not be much oil loss but it could possibly be enough to cause problems in a small coi pond?
Dave,
Refrigerants (Freon is Dupont brand name) are solivents containing no lubrication properties. Manufactors have to match oils to specific refrigerants. If intrested I will elaborate but don't want to bore.
