Review school heating timings

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Many schools have their heating coming on too early in the morning. Generally heating boilers shouldn’t be turning on before 5am in cold weather and 7am in milder weather. If your school heating comes on before this, you might be able to make changes to the heating controls to save energy and lots of money.

This activity will help you find out whether the school heating is running when the school is closed. Reducing out of hours gas use is one of the easiest, and cheapest ways of saving lots of energy and cutting your carbon emissions.

For this activity you might need a pencil and paper to write down your findings so that you can share these with your teachers, headteacher, the school caretaker and other pupils.

How to carry out this activity

  1. Gas is the most common energy source for heating in schools, although some schools use electricity or oil for heating. A gas boiler works by burning gas to heat up water, which is then pumped around the school to heat up the radiators.
    When an example school used gas over the past year. 'School day closed' is the gas used in the evenings and early mornings during term time.
  2. This pie chart shows you how much gas your school uses at different times.  How much gas does your school use on school days when pupils aren't in school ('School Day Closed')?   For many schools this is the gas used before pupils comes in at around 8.30am and after 3.20pm, but this could be different for your school, especially if your school has lots of before or after school clubs.  Can you find out how much this costs?
  3. How much could you save if you reduced the amount of gas used when the school is closed by 10%? By 20%? Depending on when your heating goes on you could maybe even cut your gas use by up to 50%!  How much would this save you? The school will always need to use some gas before the start of the school day, so that it is warm for when teachers and pupils arrive, but most schools could reduce the amount of gas they use.
    Gas use over 7 days for our example school (kW)
  4.  This chart shows how much gas you have used over the last 7 days for which we have data. (If you are trying this activity in the summer months then you might not see any gas use.  This is great - it means your school isn't wasting gas on heating in the summer!)  Can you see what time your school heating comes on in the morning? How many hours does it come on before pupils come into school? Each coloured line shows a different day.  Does your heating come on at the same time each day, or does it change? Are weekends the same as weekdays? Are there any surprises?
  5. When does your school heating turn off? Do you think there are still people in the building at that time? Buildings normally keep their heat for a while, so if a few teachers are working late, you might not need to keep the heating on across the whole school. 
    Gas costs for our example school on one day (£)
  6. This is what your gas looks like for one day.  You can see how much your school spends on gas every half hour of the day.  How much money would you save per day by turning on the heating one hour later?  How much money could you save in one day by turning off the heating one hour earlier? This may not seem like much but school is open to pupils 195 days a year: it will all add up!

What to do next

  1. Talk to the school caretaker or head teacher about changing the boiler controls so the heating doesn't come on so early in the morning. You could write them a letter or ask for a meeting and show them the Energy Sparks graphs that you've been looking at here. Tell them how much the school could save if the heating came on later.
  2. You could also ask them to switch the heating off 30 minutes or an hour earlier in the day.  If someone is working in the school later in the evenings it is usually more efficient just to heat that room with a fan heater or other small electric heater than the whole school.
  3. The caretaker may be reluctant to change the boiler controls if they think the teachers might complain the school is too cold in the mornings. You could agree to change the heating start time by 30 minutes or 1 hour first as a trial. 
  4. Check both classroom temperatures and pupil and staff comfort levels at the start of the school day. using our Measure Classroom Temperatures activity. Ask pupils and staff whether they feel too hot or cold or just right. If they feel hot or comfortable, you could try changing the heating start time some more.

Advanced knowledge 

Most larger schools have a feature of the boiler controller called ‘optimum start control’ which automatically turns the boiler on earlier in the day in cold weather and later in warmer weather. However, at many schools this automation doesn’t work properly, and turns the boiler on too early. The most common cause is if the boiler thermostat  is positioned in a cold area of the school such as the school hall or a corridor. The boiler thermostat tells the boiler the temperature of the school.  If the thermostat is in an area which doesn't have enough radiators or is near a door which is often open, then the thermostat never gets up to the heating set temperature. This means it tells the heating to come on earlier and earlier in the morning, while the classrooms get hotter and hotter. You could ask your school caretaker to try moving the boiler thermostat to another area of the school or to set the thermostat to a lower temperature.