Geothermal Alliance of Illinois Getting it Right the First Time
Things I have heard I don’t know anything about drilling I don’t know were to find a qualified Driller How do I know the driller did it right It takes up too much room It makes a mess of a nice yard
The Basic Ground Source Heat Pump System The earth loop is placed in the ground either horizontally or vertically, or it can be placed in a pond. Water and anti-freeze is circulated through the pipe, transporting heat to the heat pump during the heating mode and away from the heat pump during the cooling mode. The heat transfer takes place inside the heat pump in a water-to-refrigerant heat exchanger.
CLOSED LOOP SYSTEMS (Revision:9/15/09)
Ground Loop Options: Closed Loop Systems (Re-circulated) Vertical loop configurations Horizontal loop configurations Race Track Slinky Directional Bore Pond loop configurations Open loop – not re-circulated or closed
Ground Heat Exchanger Configurations Horizontal, Vertical or Pond? If designed and installed properly, no one system is superior to another. Criteria involved in decision Available land and/or body of water Soil conditions Excavation & Drilling costs Local regulations Fusion & Flushing equipment
Loop System Materials Ground loop piping (250+ year life) –Plastic pipe – high density polyethylene (HDPE) which is a higher grade than natural gas pipelines –Heat fusion method of joining pipe & fittings – very reliable method which makes one continuous pipe (DR11) –Antifreeze heat transfer solution-Food grade –50 year Manufacturer warranty on pipe
Vertical Loop Systems
Bullet Style U-bend
Drill and Install Loop
Vertical loop rules of thumb Minimum of foot between bores Hole depths vary between 300’ and 500’ deep Typical size is 6” or smaller Grouted with Bentonite to prevent aquifer contamination and aid in heat transfer Typically 200 to 400 pounds of sand is added to each bag of bentonite
Grout loop
Why Grout? It protects the groundwater It adds in the transfer of heat It required by code Grout ranges between.45 – 1.1btu/hr/ft Permeability of 10 x -7 cm/hr
Horizontal Loop Systems
Typical Horizontal Loop Configurations
Slinky Loop System
Typical earth slinky dimensions (600’ coil)
Directional Bore System
Pond Loop Systems
Typical Pond Loop Configurations
The Present and Future Geothermal regulation is currently a mess New regulations are in process The bill is passed JCAR Not sure what forms will look like Can’t regulate pipe or grout Start Date?????????????
Illinois State Water Well Drilling Code Defines “Closed Loop Well” “a sealed, watertight loop of pipe buried outside a building foundation which is intended to reticulate a liquid solution through a heat exchange.” This is the only definition of a loop in the code Loops must be grouted from bottom up
Water Well Drilling Code States that in Section A) Shall be grouted from the bottom up B) No closer than 200’ from water well C) If same owner 75’ D) Liquid must be under pressure Must be methanol, ethanol, propylene, Calcium chloride or ethylene glycol Maximum of 20% solution
States Water Well Code Defines grout as: Bentonite Grout: “…mixture of sodium bentonite and water….minimum of 20% solids and water.” Neat Cement Grout: “…94 pounds of cement to not more than six gallons water. Additives … may be added up to 6% to control shrinkage Geothermal grout with sand is not addressed
DuPage County Requires Permits and a licensed driller Only allows propylene glycol “food grade” Submittals on all materials Fees Grout inspections Follows code to the letter
Cook County Requires Nothing at this time
Lake County Requires Permits by a licensed driller or IGSHP installer Fees Site plans Follows the state for anti-freeze Does grout inspection on occasion
Winnebago Requires: Registration fee Licensed driller Construction reports Does inspect grouting Submits paperwork to the E.P.A. and considers all geo loops Class 5 injection wells
Will County A quote for one of the inspectors, “Just do a good job…”
The future Once the new code takes effect: All projects except open trench will require permits Must be done by licensed Companies Permit drawings showing loops and lateral distances Anti-freeze type on permit Fees: $100 for first 10 then $10 each
How to pick driller Ask for references and licenses Ask for Certifications, IGSHPA, GAOI Tell the driller what you want Require they provide insurance cert Require that the flush, purge, and test field Look at the loops Get a DETAILED contract
Questions?