About Twister

TWISTER(tm) Geothermal Heat Exchanger Technology
Proven technology with a “twist” - reduces the cost of the vertical loop field by an average of 20%!

  • Four 3/4” loops
  • Cut drilling up to 50%
  • 70 % lower BTR
  • Centralized tremie system
  • Continuous reels or coils
  • No field assembly

TWISTER(tm) Geothermal Heat Exchangers are patent-pending systems that allow the simultaneous installation of 4 loops around a central Tremie conduit in a single vertical bore hole.

Borehole with one loop and a Tremie pipe

Borehole with TWISTER Pipe (4 loops and a central conduit)

TWISTER exchangers use 3/4” ASTM D3035/D3350 Cell Classification 445574C SDR 11 or 13.5 HDPE (IGSHPA Requirement) pipe spirally wound around a central 2” center pipe used to guide the Tremie pipe. Supplied on coils or reels, with factory prepared u-fittings, installation is quick and easy. Performance Characteristics are shown in the table:

Formation Thermal Conductivity      Grout Conductivity       6” Borehole Thermal Resistance (BTR)      Bore Depth per Ton.     
TWISTED Pipe:    1.6 0.4 .085 130'
Standard:    1.6 0.4 .276 210'

Gaia Geothermal Ground Loop Design software has demonstrated that up to 50% reduction in loop length is possible.*
*Results will vary by installation. Follow IGSHPA guidelines

O.D.        Center Pipe         Loop Pipe             Loops           ASTM           Cell Classification      
4.475          2 HDPE            3/4” HDPE (SDR 11/13.5)         4        ; D3035/D3350         445574C    


"I have used Agreenability's TWISTER product on several jobs. In each case the TWISTER was easy to install and because of the reduced amount of drilling I saved thousands of dollars on the cost of each loop field. I will continue to use the TWISTER for all my vertical jobs in the future."

Antonio Poccia, Perfection Contracting, Newton, NJ

"TWISTER is, on a foot by foot basis compared to conventional loops, the best high-density polyethylene U-bend ground heat exchanger that can be installed. It ensures quality grouting, great heat transfer and circulator pump energy savings. This is the premium product for closed loop ground coupling devices. It will prove itself as teh monitoring data unfolds."

Peter Tavino, PE, Certified Geothermal Designer, IGSHPA Trainer