Bryant 50YEW Design Manual page 43

Horizontal (Trenched or Bored) Loop
Pond/Lake Loop
Pond or lake loops are one of the most cost-effective closed
loop installations because of the limited excavation required
(supply and return line trenches to the pond). Pond loops
require a minimum of about 1/2 acres [0.2 Hectares] of land and
a minimum depth of 8 to 10 feet [2.5 to 3 meters]. Like other
Bryant Geothermal Heat Pump Systems
Part III: Source Side Design / Closed Loop Design
Horizontal loops may be installed with a trencher, backhoe or
horizontal boring machine. Excavation costs are usually less than
comparable vertical loops, but signifi cantly more land space is
required. For rural installations, horizontal loops can be very cost
effective. Pipe is typically buried around fi ve feet [1.5 meters]
deep, and may be confi gured in a variety of layouts, depending
upon available space and the cost of pipe versus the cost of
excavation. Between one and six pipes per trench are buried
and connected to a header system. Closed loop design and
installation guidelines (later in this section) provide details on
horizontal loop designs.
closed loop installations, pond loops utilize polyethylene pipe,
but are typically laid out in a coil or "slinky" arrangement. Closed
loop design and installation guidelines (later in this section)
provide details on pond loop designs.
Water-to-Water System Design Guide
41