Artificial vacuum is very useful to increase the sap flow from your aerial tubing system. Commercial vacuum systems will cost several thousand dollars to set up but homemade systems can be produced for a few hundred dollars or less. Vacuum systems can be set up both in areas with or without electricity. Gasoline driven systems may cost twice as much; however, the payback period when adding artificial vacuum on well designed tubing systems can be very fast (for some a year or less). During years when the weather is moderate to poor for sap production, vacuum can dramatically increase sap flow. A sap extractor is shown below.