Occupancy-Based Heating: How Sensors Cut Energy Waste

How do sensors integrate with a Building Energy Management System?

The HeatingSave Building Energy Management System uses an advanced AI-powered algorithm to determine the most efficient time at which the heating should be turned on or up to reach the desired temperature at the desired time, and when it should be switched off again, and then acts on this by controlling the heating system of a site.

However, HeatingSave can also make adjustments to the heating output and time by using readings from sensors throughout the property, both internal and external, including sensors for temperature, occupancy, humidity, sound, carbon dioxide, light, precipitation and volatile organic compounds (VOCs).

PIR occupancy sensors are used by HeatingSave to detect if there is anyone in a room or heating zone; HeatingSave will then adjust the heating in that zone if it is not being used, to ensure that energy is not being wasted.

What is a PIR sensor?

A Passive Infrared Sensor (or PID — Passive Infrared Detector) detects infrared (IR) radiation emitted by people, objects and animals, and can identify when the IR radiation changes. Infrared radiation is invisible to the human eye but can be felt as heat.

People give off more IR radiation that inanimate objects, which means the PIR sensor can detect when a person is moving inside a room by identifying that a part of the room has changed its heat emissions. In the case of a person moving around, this would show areas increasing in IR radiation as the person moved to them, then the radiation amount returning to its previous level after they change location.

The amount of IR radiation emitted can change depending on the object emitting it; for example, a human body might be the same temperature as a warm oven, but each emit heat in different ways, which causes changes to the amount of IR radiation. PIR sensors can detect if that amount of radiation changes, so a person walking in front of the oven would still register as a change.

Considerations when using PIR sensors

PIR sensors have an extensive range of uses, but there are some considerations for their use.

Occupancy sensors detect changes in IR radiation, so if a person is stationary they may not be picked up by the sensor. It is also important to note that this works inversely too: movement or temperature changes of any kind can trigger the sensors. While they can be configured with a higher sensitivity threshold (which could ignore pets, for example), some things might still trigger the sensor, such as a heating or cooling vent blowing heated or cooled air in front of the sensor. In the same way, sunlight streaming through a window and heating up an area of the room could cause the sensor to register an occupancy.

PIR sensors should also be directed away from windows, as strong infrared sources outside, such as cars driving past, could be detected.

HeatingSave installers have extensive experience of the ideal positioning of the sensors to ensure they provide the optimum coverage and best results.

How do occupancy sensors help to improve energy efficiency?

Occupancy sensors contribute to an efficient heating system by informing the central unit of the Building Energy Management System whether there is anyone in a room, and therefore if it is necessary to provide heat.

By dividing a property into heating zones (which could be rooms, larger areas, or specific workspaces), occupancy sensors can be used to determine if each zone is being used. HeatingSave will then calculate, based on the programmed settings and data from the temperature sensors, whether it is necessary to turn down the heating.

In this way, HeatingSave occupancy sensors help to cut energy waste by limiting the amount of energy used to supply heat to unused rooms or zones.

Every property has different requirements, so get in touch today to discuss your needs with our expert team.