Ever needed to get a hydronic heating system up and running before the building it serves has domestic water
service? Perhaps there've been times you've hesitated to fill a sparkling new system with cloudy water from the
site's newly drilled well. Or maybe you've pondered the best way to add antifreeze to a system. These are all
situations in which a "purge cart" can be a valuable tool.
I built my purge cart out of necessity in 1987. I needed it to fill, purge and add antifreeze to the buried tubing
loop supplying a newly installed geothermal heat pump system. The earth loop consisted of two parallel
circuits of 1-inch polyethylene pipe, each 500 feet long. The pressure and flow available from my well pump
just wasn't up to ridding the piping loops of entrapped air.