School · Domestic hot water
Domestic hot water in school: what the SRI measures
Domestic hot water covers the boiler or storage tank: is water heated on a fixed schedule or based on use, can the system use cheap electricity or solar heat, and is the circulation pump controlled smartly.
In short
- 1This page shows what the Smart Readiness Indicator measures for domestic hot water in schools.
- 2In schools, this domain counts as 1 of 3 domains in the overall score.
- 3Smart control of boilers and circulation pumps can save energy without students noticing any difference.
Weight of this domain for this building type
Which services count
| Service | Lowest level | Highest level | Advice |
|---|---|---|---|
| Control of DHW storage charging (with direct electric heating or integrated electric heat pump) DHW-1a · A · 3 levels | Automatic control on / off | Automatic on/off control, scheduled charging enable and demand-based supply temperature control or multi-sensor storage management | at least level 1 |
| Control of DHW storage charging DHW-1b · A · 3 levels | None | Automatic charging control based on local availability of renewables or information from electricity grid (DR, DSM) | at least level 1 |
| Control of DHW storage charging (with solar collector and supplementary heat generation) DHW-1d · 4 levels | Manual selected control of solar energy or heat generation | Automatic control of solar storage charge (Prio. 1) and supplementary storage charge, demand-oriented supply and return temperature control and multi-sensor storage management | – |
| Sequencing in case of different DHW generators DHW-2b · 5 levels | Priorities only based on running time | Control according to dynamic priority list (based on current AND predicted load, energy efficiency, carbon emissions, capacity of generators AND external signals from grid) | – |
| Report information regarding domestic hot water performance DHW-3 · A · 5 levels | None | Performance evaluation including forecasting and/or benchmarking; also including predictive management and fault detection | at least level 1 |
Worked example
If everything in this domain is at level 0, the domain contributes nothing. At the highest level for all services, the indicative total score for this building type rises by about 8 percentage points (from 31 to 39 percent, with all other domains at level 1).
Why does domestic hot water count in schools?
The Smart Readiness Indicator (SRI) divides a building into nine domains. Domestic hot water is one of them, with its own smart-ready services that describe the behaviour of the boiler, storage tank, and circulation pump.
In schools, this domain accounts for 1 of the 3 domains used in the score. This is less weight than in buildings with many showers or kitchens, but still relevant.
Schools follow a fixed schedule with long holiday periods. Domestic hot water is often kept warm even when no one is present, which wastes energy.
Which smart-ready services belong to this domain?
The methodology distinguishes several services. DHW-1a and DHW-1b address loading of the hot water storage: is this done at a fixed time, or does the system account for available solar energy or grid signals.
DHW-1d describes the same logic for systems with a solar collector alongside an auxiliary heat source. The highest functionality level combines automatic control with demand-driven temperature regulation.
DHW-2b manages the sequence between different heat generators, for example solar energy versus a boiler. DHW-3 concerns reporting: can the system signal faults or forecast performance, or does it only display current values.
What does this mean for older school buildings?
Many schools still have systems with simple time clocks. This corresponds to a low functionality level within the SRI methodology, without adjustment for actual use or holiday periods.
With limited budgets, priorities must be set. A time-based load release that accounts for the school schedule often yields more benefit than a completely new system.
How does this domain relate to the rest of the score?
The SRI has seven classes, ranging from above 90 percent down to below 20 percent. Domestic hot water contributes less weight in schools than heating or ventilation, which affect indoor air quality in classrooms.
Even so, every improvement counts towards the total score, because the weighting factors of all domains together determine the class.
What this means for you
- Owner
- As the owner of a school building, it is useful to check whether the hot water boiler is linked to the school schedule rather than a fixed time clock. This can reduce wastage during holidays with limited investment and provides a concrete step towards a higher functionality level within the SRI.
- Tenant
- For students and staff, little changes in practice: hot water is available when needed, without noticing how the system manages this. A well-tuned system prevents unnecessary energy consumption during unoccupied periods, without any loss of comfort during school hours.
- Advisor
- When assessing this domain, it is important to examine the current functionality level of the load control and whether performance data or sub-metering is already available. Given the limited weight of this domain in schools, it is advisable to assess domains with greater impact first before investing here.
Next step
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