The installation of the solar panels is currently the largest solar thermal cooling and heating project in Canada. It involves 162 solar thermal collectors being assembled onto the roof of the retirement home. Each of these collectors, made by the German company S-Power, includes 20 evacuated tubes produced by NARVA, a German company as well. The collectors are installed over 9 rows with 18 collectors per row. This combination includes 3,240 tubes. The S-Power evacuated tube collectors use 30-40% less space than other solar collectors making it possible for them to fit onto the roof of the facility. A propylene glycol mixture designed specifically for high temperature solar thermal applications flows through the tubes collecting the heat. Over 17,000 litres of solar-glycol is used in the system.
The collectors are mounted to aluminum racking which is attached to metal cladded laminated wood beams. These beams are attached to mounting supports which are then fastened through the roof to the main structural walls of the building. The collectors are assembled well above the snow line of the roof, to enable them to function properly all year. Piping sizes on the project ranges from ¾ at the collectors all the way up to 4 into the mechanical room. All piping is stainless steel outside with some copper inside. Over 4,000 feet of insulated piping was used to connect the system.
The Yazaki WFC-SC 30 ton (105kW) absorption chiller and storage tank are installed on the 13 thick concrete equipment pads. In addition to the concrete pads required for the equipment, additional concrete was poured, making a patio for the residents of the home.
The Yazaki absorption chiller is connected to the existing central cooling system and will reduce the electrical consumption of the two TRANE chillers. This chiller will convert the solar hot water into chilled water.
Thermal energy will be stored in a 3,000 gallon storage tank which will be used as a battery' to store energy and allow the system to operate during intermittent clouds or after the sun has gone down. The tank has been insulated with urethane foam and painted for UV protection.
The mechanical room houses the heat exchanger, pumps and the control system. The heat exchanger is a double wall plate on frame exchanger which weighs 1,800 lbs and is able to transfer 1.2 million BTUs per hour to the heating system. The solar domestic water uses a 500,000 BTU double wall brazed plate heat exchanger and the swimming pool uses a 500,000 BTU shell and tube heat exchanger.
Each of the heat exchangers use a pump to pull hot solar fluid from the storage tank when needed and pushes it through the heat exchanger to transfer the heat.
The control unit is a touch screen control provided by Proterra Solar. The control is very sophisticated and coordinates all functions of the system. The control measures total output of the solar system as well as the solar contribution for each load (swimming pool, domestic water, heating system and cooling system). This allows us to monitor the effectiveness of what has been collected against what is being used.
There is a back up heater (or chiller) for each load point. These were existing and will continue to operate as they always have, should the solar system not provide enough energy on a rainy day or snow storm. The integration is seamless so the residents will see no interruption of services.