This has been a really cold winter so far, and there’s still a lot more winter to come. Fortunately for our viva riders on the newly opened Highway 7 rapidway, keeping you warm was one of our priorities when we designed the new median stations. Like everything else with vivaNext, a lot of engineering analysis and planning was done to ensure the enclosures provide the right level of comfort in the winter. Here’s the background.
When we opened the prototype vivaNext station at Enterprise and Warden, we used a well-regarded heater that our original analysis showed would keep things adequately warm. But at 1000 watts, the heater wasn’t quite powerful enough to provide the level of comfort we wanted to achieve. So when it came time to design the shelters for the larger rapidway program, we went back to the drawing board.
First, we determined how warm we wanted to make the shelters. Given that most people are only waiting for a few minutes, we didn’t want to make the shelters so warm that people would need to take off their coats. Bearing this in mind, we decided that the right target would be to heat the shelters to 10 degrees Celsius.
Next, we needed to find a technology that would be energy efficient: with the enclosures’ semi-outdoor design, using traditional space heaters would, in addition to requiring exhaust systems and airflow, be very inefficient. We decided to use radiant heaters, which work by projecting heat energy directly onto the people in the shelter (if you’ve watched your kids play hockey at a rink, you’ll know how effective this kind of heater can be). Another benefit is that radiant heaters quickly ramp up to full power but can be shut off quickly as well, conserving energy.
Last, we needed to determine how many heaters we’d need to install to achieve our target temperature. We did a computer simulation of the bus shelter, programming in local weather data to assess the thermal conditions in the shelter for every hour throughout a typical year. The model took into consideration the concrete and glass design of the shelter, as well as replicating wind speeds and temperatures.
Using all this information, we decided that four heaters, each providing 3000 watts of power, would be sufficient to achieve the 10 degrees target: that’s 12,000 watts per enclosure (a typical electric fireplace is between 750 and 1500 watts). Sensors on the units detect when someone walks into the enclosure, starting the heater; if the sensors don’t detect any other movement, the heaters will shut off after 30 minutes. And to help keep the warmth in the enclosures, we’ve installed push buttons on the doors so they close automatically, as well as installing winter covers over the ventilation louvers on the doors.
We hope you are pleased with the comfort we’ve been able to design into the shelters, and are happy to make winter a little warmer for our viva riders.
