homenews and insights managing heat waves

Managing heatwaves

By James Wilson
10 August 2022

Project Sales Engineer

Meet our SSE Energy Solutions experts


Extreme temperatures can be detrimental to both the occupants and systems in your buildings. Here are some common symptoms that show an inefficient BEMS is contributing to the problem, and what you can do about it.

Symptom 1: Excessively hot areas

Although there is no legislation in the UK for a maximum permitted working temperature (think of steel mills), the GOV.UK website1 states that employers must stick to health and safety at work law, including:

  • Keeping temperatures at a comfortable level
  • Providing clean and fresh air

The consequences of an uncomfortably high temperature can include a reduction in productivity, financial penalties and even cause damage to plant and other equipment.

There are several ways that your BEMS can help.

  • Check your BEMS to make sure that all plant is in automatic control, rather than ‘in hand’ (manual control)
  • Check that all sensors are reading correctly. For example, a space with a faulty sensor might register the room as being cooler than it is, thus preventing additional cooling from being applied
  • Check the location of sensors. A temperature sensor that has been located next to an air conditioning unit would result in the wrong level of heating or cooling being applied

Symptom 2: Failing or unreliable plant

If your control strategy is correct and plant is in automatic control, a tell-tale sign that your BEMS is operating inefficiently can be failing or unreliable equipment. Some failing equipment is less obvious. If you have obsolete BEMS controllers installed they could be reaching the end of their lives and running spurious software.

  • If it has been set up correctly, the BEMS should provide logs as to which equipment is regularly going into fault. Review this data to identify which plant is contributing to overheating.
  • Compare the controllers on-site with current products. CIBSE guidelines are that a BEMS controller has a lifecycle of 10 years

Symptom 3: Excessive energy use

Sunny periods mean two things are normally in abundance – light and heat. Both are major contributors to the running costs of a building. If your gas and electricity usage have not decreased during sunny spells, there could be an issue with the control strategy. This can be dependent on whether your building uses mechanical cooling.

Excess heat sometimes leads to building users opening doors and windows. As a result, plant could be enabled where not required if your BEMS software is unable to account for this.

  • Evaluate the control of your building to make sure that during extreme heat the building can react and make the most of the savings presented by free heat and light

Symptom 4: Stuffy air

The need to keep doors and windows closed may result in air which is stale as well as hot. This perception of the air feeling “stale” may be the result of high levels of CO2 which, as well as being unpleasant, have been found to impact people’s cognitive performance2.

  • Check that your ventilation strategy allows for adequate air changes
  • Consider installing CO2 sensors both to detect the gas and to provide an indication of occupancy levels in a room

If you would like help to minimise the impact of heat waves, contact your local branch.