13th Energia Awards 2002
Category: Research and development
Project title: Récupération Énergie Terrestre [earth energy recovery]
Participant: Climatisation/Réfrigération P.M.G. inc., 709 Fortin Street South, Alma, QC G8B 2S8
Telephone: (418) 668-6154
Fax: (418) 668-0487
E-mail: pmgcli@gc.aira.com
Presented by: Céline Maltais, Associated Shareholder
Paul Paradis, Associated Shareholder
1. Description
The pilot project consists of testing an earth energy-based heating system in a year-round greenhouse used to grow plants. The system should provide enough heating power to meet the requirements of an environment with high energy loss, such as a greenhouse located in a region like Chicoutimi, which has a severe climate.
A heat transfer fluid transmits energy from the ground outside to the building. The energy is transferred from the fluid to the heating system by means of a ground-source heat pump.
Based on the principle of direct expansion, the prototype combines heat by placing the heat pump condenser in the concrete slab.
A traditional plastic greenhouse, with an area of 122 m2, was equipped with this heating system. The goal of the project is to demonstrate the feasibility of the technology and to determine its energy efficiency as compared with conventional heating systems.
The components consist of the following:
- An evaporator serving as the energy collector buried inside the greenhouse.
- A power module including refrigeration compressors and control and safety accessories.
- A condenser returns the energy to an emitter, i.e. a concrete slab inside the greenhouse.
2. Energy impact
The goals are to:
- reduce energy costs by 20%;
- obtain an energy efficiency ratio of ± 3.5;
- provide enough energy to meet 70% of annual demand;
- maintain a minimum temperature of 10°C during the night, using the heating system, and 22°C during the day, with no backup heating;
- promote plant growth.
3. Technological innovation
The principle of earth energy is already being used in many projects. However, this project is innovative because the system consists of collecting heat with a heat transfer liquid, which circulates through a network of tubes buried about 90 cm below the surface outside the greenhouse, and transferring it to a concrete slab located beneath the plants.
4. Costs/benefits
The annual cost of heating totals $1,850/year, i.e. $15 per m2/year, as compared with the current annual average cost of conventional heating with natural gas, which is $35 per m2/year.
Recovery of the initial investment takes ± 4 years.
5. Secondary impacts
This project involves no combustion of fossil fuels, which produce emissions of CO2 and NOx and pollute the atmosphere.
The refrigerant used in the system to replace CFCs, i.e. HCFC - R41OA, meets current Canadian standards. One of its particular physical properties is that it boils at 1 ATM (-52.7°C).
In addition, this project enables production time to be reduced by 10%.
Carried out thanks to: Gaz Métropolitain
A source for the future
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