Save on HVAC costs with smart thermostats and more efficient equipment

Heating, ventilation and cooling (HVAC) systems are the largest source of energy use for commercial and industrial buildings.

They often power building systems as well as equipment.

There are a number of ways to reduce their impact. These range from behavioural changes and maintenance to complete retrofits.


  1. Make a plan to improve your HVAC
  2. Change your behaviour
  3. Change your HVAC configuration
  4. Upgrade your HVAC equipment
  5. Get finance and support

Make a plan to improve your HVAC

Your building’s HVAC system is an important part of making plans to retrofit your premises because they:

  • typically use a lot of energy
  • can be costly to replace
  • affect comfort and productivity

You should improve your building fabric before upgrading your HVAC if you have an older building with poor insulation.

Figure out when changes are required

There are several upcoming dates that could affect your plans, including:

  • energy performance standard increases in 2023, 2027 and 2030
  • proposals for fossil fuel heating phase out  – the government has consulted on proposals and will publish a response in due course
  • business retrofit funding programmes available up to 2025

Find out more about lining up a retrofit.

Do a walk around

Start by understanding how your existing HVAC system works.

Identify the components and control systems and check their condition.

Ask building occupants about their level of comfort and remind them what controls they can use.

Ask your landlord about their retrofit plans and what control you have to change HVAC controls and equipment if you rent your premises.

Submeter your HVAC system

Think about submetering the electricity or gas lines that power your HVAC system to get an accurate measurement of energy consumption.

Use the energy consumption measure to identify HVAC costs and potential savings.

Submeters should be installed by professional technicians. Depending on your HVAC system a basic electricity submeter costs from £20.

Change your behaviour

How you use your HVAC system can affect costs significantly.

Use the following low or no-cost measures to start improving performance without sacrificing comfort.

Set your heat lower

If your thermostats can be adjusted by room or activity levels, set them to:

  • 19 to 21°C where people are sitting or stationary
  • 16 to 19°C where people are active
  • 16°C in any room when nobody is on site

Check specific temperature ranges for your business type and activity in the Carbon Trust’s Heating and Ventilation guide.

Avoid overcooling in offices

To avoid overcooling, set your air conditioning to the highest comfortable temperature for the hours people are at work.

Studies on office workplaces have shown that productivity starts to go down once temperatures exceed 24°C.

Create a temperature ‘dead band’

To prevent competition between your heating and cooling systems, set your thermostat to create a gap between one switching off and the other coming on.

This gap where no heating and cooling is required is called a ‘dead band’.

A 2016 study showed that a 4°C dead band resulted in an average of 12.7% savings on heating and cooling energy.

Do operations and maintenance checks

Keeping your systems in good working order keeps running costs down and reduces the risk of unscheduled down time.

You can do certain tasks, such as cleaning ducts or replacing filters. Call a technician for tune ups, calibration and programming.

Check the Energy Star website for more detailed advice on operation and maintenance.

Change your HVAC configuration

Simple changes to your existing HVAC setup can increase efficiency and potentially avoid costlier upgrades.

Get a smart thermostat

Smart thermostats can help by:

  • controlling your heating and cooling systems through a digital display or app on your phone
  • giving you more flexibility to control and schedule temperatures

You can programme a schedule manually or set it to learn when you’re present and adjust automatically.

Many smart thermostats have energy saving modes to set temperatures to a comfortable limit.

Move thermostats

Smart thermostats won’t work properly if they are affected by sunlight, draughts or heating and cooling sources. Install them on interior walls away from heat and cooling sources instead.

Switch to a wireless control system to avoid the expense of running wires if your current thermostats are hardwired.

Simple thermostat and receiver bundles cost less than £100 and can be installed yourself. Larger buildings with complicated systems will need professional installation and cost more.

Install better controls

If your HVAC system allows for central control over different components and areas, make sure they are working together properly.

This includes:

  • creating ‘zones’ with different HVAC settings per area
  • timing HVAC operation to anticipated building demand
  • boilers and circulating pumps shutting off at the same time
  • timing the operation of extraction fans

Check the Carbon Trust’s Heating and Ventilation guide for more guidance.

Upgrade your HVAC equipment

You should replace components or the entire system if equipment is at the end of its lifespan or too costly to operate.

Take a ‘whole building’ approach and consider HVAC upgrades if you already need to upgrade building fabric.

When sourcing new equipment it is important to avoid ‘like for like’ replacement if more efficient systems are available.

Replace motors and drives

New motors and variable speed drives can have a major impact on HVAC efficiency if your system needs air and water supplied to equipment.

Get a heat pump or ‘hydrogen ready’ boiler

Decarbonising your building’s heating system is an important net zero priority as it uses significant amounts of fossil fuel.

The government has proposed a ban on installing new fossil fuel-based heating systems. This ban will be phased in from 2024 to 2035.

Alternatives include:

  • heat pumps for heating, cooling and hot water
  • ‘hydrogen ready’ boilers that use natural gas but can switch to hydrogen

Heat pumps are the preferred option because they run efficiently on the existing electrical grid.

It is unclear when the UK will be able to introduce hydrogen as a fuel in large quantities. According to the government’s Heat and Buildings Strategy this decision will be taken by 2026.

Install a building energy management system (BEMS)

Consider running any new HVAC equipment on an energy management system that monitors the performance of your entire building.

Energy management systems:

  • are networked
  • can be controlled in real time using computers or mobile phones
  • allow settings to be changed quickly and easily
  • can reduce total energy costs by 10% or more

Find out more about monitoring building performance.

Get finance and support

You might find it helpful to hire a consultant to redesign your HVAC system if your business needs help and has financial resources.

Check our retrofit funding page to find out what finance is available from banks, government schemes and local councils.

Find finance and support for your region.

Check our case studies for examples of other SMEs that have successfully cut their costs and carbon emissions.