Apartment building · Domestic hot water
Domestic hot water in apartment building: 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 how smartly an apartment building manages hot water.
- 2It covers the control of the boiler or storage tank, and whether the system accounts for cheap electricity or solar heat.
- 3For apartment buildings, this domain weighs 2 out of 3 points in the score, so it carries relatively high importance.
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 | level 2 or higher |
| 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) | level 2 or higher |
| 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 | level 2 or higher |
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 hot water count in the Smart Readiness Indicator?
The Smart Readiness Indicator (SRI) measures how well a building is prepared for smart, energy-efficient technology. Hot water is one of nine domains that the SRI assesses.
In apartment buildings, this often involves a collective installation: one central boiler or storage tank for the entire building. The choice between collective heating and individual boilers per dwelling makes a significant difference to the score.
Which smart-ready services are assessed?
Within this domain, the SRI looks at multiple smart-ready services: functions that can make the building smarter. Each service has functionality levels from 0 to 4, where a higher level means more automation and control.
- Loading of hot water storage: is the water heated at fixed times, or does the system account for available renewable energy or signals from the electricity grid?
- Solar collectors and backup generation: does solar energy take priority, and does the system automatically adjust the supply temperature?
- Prioritisation with multiple heat sources: does the system choose the most efficient heat source based on efficiency, CO2 emissions, or even predicted demand?
- Performance reporting: does the system show only current values, or also historical data, forecasts, and fault detection?
What does this mean for the building's score?
For apartment buildings, the hot water domain carries relatively high weight: 2 out of 3 possible points. This is because water heating makes up a substantial part of energy consumption in residential buildings.
A building with only a manually set boiler scores at functionality level 0 or 1. A building with automatic loading control based on energy prices or solar heat can reach level 2 or higher.
The final score is expressed as a percentage and placed in one of seven classes, from below 20 percent to 90 to 100 percent.
What this means for you
- Owner
- As a building association or housing corporation, it is worthwhile to have the collective boiler assessed to see whether it uses smart control technology, such as time-based load release or control based on energy prices. This can lower energy costs for all residents and raises the building's score in a domain that carries relatively high weight for apartment buildings.
- Tenant
- As a resident, you will notice little of the technology behind the boiler, except that hot water is always available on time and your energy bill may be lower. A smarter system adjusts water heating to times with cheap or renewable electricity, without requiring anything from you.
- Advisor
- When making an assessment, pay attention to the distinction between collective and individual systems, as this determines which smart-ready services apply. Also check whether prioritisation between different heat sources is dynamic, as this level often determines the difference between a mid-range and a top score.
Next step
Want to know where your building stands?