Parallel piping installation with air by-pass apparatus

A piping installation placed in the earth for use with a heat pump which utilizes a liquid fluid medium for heat transfer, comprising:

• a supply header for carrying said fluid medium to a branch conduit array,
• a return header for carrying said fluid medium away from said branch conduit array,
• said branch conduit array having a plurality of individual branch conduits, wherein each branch conduit has two ends with one of said ends being connected to said supply header and with the other of said ends being connected to said return header such that said branch conduits are connected in parallel to each other across said supply and return headers,
• said branch conduit array having a last branch conduit, said last branch conduit being that branch conduit which is connected to the supply header at a location downstream from the other branch conduits,
• by-pass conduit means having two ends and being connected between said supply header and said return header,
• adapter means for connecting said respective ends of said by-pass conduit means to the respective headers,
• said by-pass conduit means being connected to said supply header at a position close to the supply header end of the last branch conduit of said array and said by-pass conduit means being connected between said headers such that said by-pass conduit means allows a portion of said fluid medium to flow directly from the supply header to the return header and by-pass the branch conduit array,
• said by-pass conduit means having a length and an inside transverse cross-sectional area so as to present substantially more resistance to the flow of said fluid medium than to the flow of air trapped within said piping installation, wherein a substantial portion of the fluid medium in the supply header at the last branch conduit enters the last branch conduit with the remaining portion of the fluid medium entering the by-pass conduit means,
• said length of said by-pass conduit means being sufficiently large so as to allow proper spacing between said supply and return headers, wherein thermal interference between said supply and return headers may be reduced.