59 Glenforest Apartment Building

Killam Properties Inc
70 Solar Thermal Panels
Domestic Hot Water Preheat
Thermo Dynamics Ltd – G Series
Panel location: 
Roof mounted on concrete slab
Over 13,000L of annual heating oil savings
Carbon impact: 
36.5 tons of CO2 Emissions reduced annually
59 Glenforest Drive
Halifax, NS


The diagram below shows the schematic of the Solar Hot Water System installed at the Glenforest.

The 70 roof mounted panels are shown at the bottom of the image.  Heating fluid - diluted Propylene-Glycol - flows through two parallel arrays simultaneously, each array having 25 and 45 panels respectively and an independent circulator. Within each array there are sub-groups plumbed in series, and each sub-group contains 5 panels plumbed in parallel. 

The heated glycol (Red) returns from both arrays and mixes together before flowing through four heat exchangers in series. Once the collected heat is transferred from glycol to water, the glycol is then split and circulated back out to the arrays.

The blue line in the centre of the figure labeled "COLD SUPPLY" illustrates the city supply water entering the system. Prior to this installation, the cold supply water would have been entirely heated by the existing oil fired boiler. The pre-heated water is stored in 8 x 200 US Gallon storage tanks. The water in these tanks is circulated through the four heat exchangers when there is solar-heat to be extracted from the glycol. The thick red line leaving these tanks marked "SOLAR PREHEATED SUPPLY" is the solar preheated water on its way to the boiler.

The overall temperature difference of the water entering and leaving the system is shown as T1 and T2 respectively. The difference between these two temperatures is the heat added by the system.

The volume of Domestic Hot Water used is monitored every minute, and accumulated over the course of each day and month. The minutely flow is labeled as “Flow”.  On average, this building uses about 16,000 L of hot water every day.

Knowing the temperature difference between T1 and T2 every minute and the volume of water used each minute, one can calculate the amount of energy provided by the system in Kilowatt hours, and also the amount of heating oil saved by the building. T3 is the temperature of the water leaving the oil-fired boiler.

All data being collected, the daily and monthly accumulations of flow, the total energy produced, heating oil saved, and the CO2 offset are posted live to this image every sixty seconds.

  • Commercial Solar