Procedures – Geothermal energy

Since 2004, we offer geothermal drilling services for residential and commercial projects. Till this day, we have accomplished many commercial projects (see our achievements). We are able to refer you qualified and competent designer-installers that will know how to guide you trough your new construction or during the renovations of an existing building.

While realizing a commercial project, you will need the assistance of different specialists to analyze the annual heat reports, calculate the heat capacity of the building, do a soil conductivity test and calculate with precision the required length of the geothermal loop. The factors that influence the dimensions of the loop are :

  • The heating and cooling needs of your house ;
  • The humidity degree and the nature of the soils ;
  • The burial depth of the loop ;
  • The climate ;
  • The quantity of snow that covers the loop in the winter ;
  • The size of the buried pipes and the distance between them.

Here are the steps to follow to obtain a geothermal system :

1. For any residential, commercial or institutional project, the first step is to choose a designer-installer and a driller that are accredited by the CGC and that have the required qualifications. You should also check with your local municipality to see if it requires a permit for geothermal drilling.

2. When your entrepreneurs are selected, your designer-installer will evaluate your project to determine the number of geothermal wells that are needed, the length of each one and the size of the field area. He also will be able to guide you trough the purchase of the heat pump and interior equipment. Since Les Puisatiers Protech doesn’t detain an engineer license needed for the conception, we will drill the amount of feet that will have been determined by the designer. This is why we are not, under any circumstances, responsible if the conception is inappropriate or inefficient. Hence the importance of choosing accordingly the different specialists and take references.

For every commercial projects, a test-well and a soil conductivity test will be required before initiating the overall project. This will determine the heat’s conductivity (speed at which the heat moves) and the heat’s diffusivity (ability of the ground to store and release the heat).

3. Following the previous steps, we can proceed with the installation of the geothermal heat exchanger also called geothermal loop. Before starting the work, the driller will discuss with the client to explain the procedures of the drilling work and the responsibilities of each other. In the case of a commercial project, a work methodology will be presented to the engineer for approval.

The client’s responsibilities

Property access : The client must prepare the grounds for the arrival of the drill and equipment ;

Permit : The client must verify with his local municipality to see if he needs to obtain a permit for geothermal drilling ;

Location of the well : The client must determine where the well or wells will be located on his property, without being to close to the house, to an obstacle or to electrical wires ;

Info-Excavation : The client must have the underground conducts located (if needed) such as Hydro-Quebec, gas, phone, video, water entries, sewer, subway, underground construction, etc ;

Insulation : If needed, the purchase and installation of the insulation for the horizontal pipes is of the client’s responsibility ;

Excavation : The client must at his fees, hire an excavator to dig out the trenches and fill them back up with fine sand. This step must be supervised by the client at all times ;

Property maintenance : The client has the responsibility of putting the site back in its original state.

Preview of the drilling procedures following the signature of a mutual contract

  • Discussion between the designer-installer and the driller concerning the work scope ;
  • Beginning of the drilling ;
  • Discussion between the designer-installer and the driller, while drilling, about the geology that is met, the water entries, the penetration speed and other technicalities linked to the drilling ;
  • Re-evaluation of the design if necessary ;
  • Installation of the geothermal loop, also called geothermal probe, which is previously tested, pressurized and merged by the factory as well as the installation of the E-Z Snaps or Geo-Clips spacers disposed at every 10 feet to maintain the pipes on the edges of the well ;
  • Pressure test on the vertical exchangers ;
  • Insertion of the grout that is made of a mix of water, bentonite and silica sand ;
  • Flow rate and pressure test on the vertical exchangers ;
  • Installation of the horizontal pipes ;
  • Purge the system (replace the water with the coolant fluid) ;

The privileged coolant fluid is the propylene glycol because it is non-toxic and biodegradable. In the event that you would rather use methanol for its lower price, be advised that Les Puisatiers Protech will not pour this product in your system and therefore disclaim any environmental liabilities that may arise if your geothermal exchanger should brake, for example, during the excavation.

  • Pressurize the geothermal system with air ;
  • Flow rate and pressure test on the geothermal system before burying the horizontal pipes ;
  • Insulation of the trenches if needed ;

The excavation of the trench is the client’s responsibility. The minimal depth required is of five (5) feet.

  • Backfilling of the trench by an excavator to cover up the pipes with fine sand ;

This operation is very important and must be done very conscientiously because if we bury the pipes with rocs, they could get damaged and compromise the proper performance of your system.

  • Drilling report ;

4. The designer-installer accredited by the CGC will have to install the heat pump, which assures the heat transfer between the building and the geothermal exchanger, and any other equipment connected to the conception plan.

5. An application will be made at the CGC by the designer-installer for the system’s certification to obtain a grant.

By following the previous steps, you can be sure to complete your project while staying confident about the conformity of your geothermal system. However, we remind you that this is a bref summary of the steps to follow and they may differ from one project to another.

For more information you can refer yourself to A Buyer’s Guide for residential Ground Source heat pump systems.