Basic sensor technology has already allowed us to detect and quantify the humidity and outside air temperature, and most building automation systems make informed, albeit somewhat limited, decisions about mechanical-system operations based on outdoor conditions.
However, there is growing momentum for building automation systems to incorporate more extensive weather data like rain levels, wind speed, humidity and heat index, Doppler radar forecast, severe-weather advanced alerts, barometric pressure, and more, as they all can have a significant effect on the utility use, temperature, and therefore, comfort of those inside a building. By incorporating the prediction of local weather conditions with equipment like the HVAC unit, owners and operators can significantly increase energy efficiency and climate control in their buildings.
Weather forecasts and model predictive control for energy efficiency
Model predictive control (MPC) is the only control methodology that can systematically incorporate future weather forecasts and predictions and adapt building equipment accordingly. For example, when forecast and weather data are integrated, the system can bypass municipal water supply, check rain-water collection tank levels, and alert an operator if overflow in stormwater storage is imminent.
Building owners can also use the data gathered to make informed decisions about the feasibility of installing other energy efficient items like photovoltaics or wind turbines, and predict their return on investment. Perhaps most importantly, weather related information is especially useful when looking to increase energy efficiency in the HVAC system, as weather data can be used to determine when to use a smaller chiller at full capacity versus a larger boiler at half capacity in order to save on energy and maintenance and can be beneficial for load shedding.
Model predictive control and weather forecasts for climate control
It has been proven that advanced building controls like MPC can notably reduce energy use and greenhouse gas emissions, but it also has the increased benefit of enhanced climate control. Changes in climate bring changes to the indoor building environment, creating a challenge for property managers to ensure optimal temperature ranges for occupants. External temperature, wind, humidity, pressure and sunshine all impact thermal conditions, air quality, use of water and amount of natural light in a building. There’s a direct relationship between a building’s day-to-day operations, energy needs and the weather conditions.
An MPC system can be incorporated to help anticipate the energy needs of a building based upon the data it gathers from weather forecasts and use the real-time information to optimize the building’s thermal behaviour in response. The building reacts with changes to heating, cooling, ventilation, water use, and lighting by foreseeing changes in the weather before they occur. In doing so, property managers can prevent hot radiators being left on throughout the summer or lights being left on when there’s enough natural light, allowing a building to decide when and where these resources are needed, promoting the indoor environment, occupant comfort, and energy efficiency.
The energy-efficient management of building systems will play a major role in reducing overall energy consumption and costs, and the integration of an MPC system to monitor weather forecasts works to provide the reductions and promote climate control. Property managers may not be able to control the weather, but by integrating weather data, you can at least control how your building reacts.