Geothermal Alliance of IllinoisGetting 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 12-15 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 920.180• 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?