Domestic hot water (DHW) is a fundamental element of everyday household comfort, providing hot water for bathing, washing dishes, and laundry. Modern systems, such as heat pump solutions, are particularly efficient and energy-saving in hot water production.
How does DHW production with a heat pump work?
Hot water storage tank: Heat pump systems typically use a storage tank where water can be heated and stored, ready for use.
Role of the heat pump: The heat pump uses ambient thermal energy to heat the water, which is significantly more efficient than traditional electric or gas-fired boilers.
Temperature control: The temperature in the system is precisely controlled to be optimal (typically 50–60 °C), thus avoiding limescale build-up and excessive energy consumption.
Types of DHW production
Storage system: Water is preheated and stored in a tank.
Instantaneous system: Water is heated directly when used (e.g., combi boilers).
Hybrid system: A combination of storage and instantaneous systems.
Sizing DHW systems
Choosing the right size tank is critical for comfortable and economical hot water supply.
Considering user needs:
- A small household (2-3 people): 80–120 liter tank.
- Medium household (4-5 people): 150–200 liter tank.
- Larger household (6+ people): 250–300 liter or larger tank.
Considering peak periods: It is important that the system can meet the household's water demand during peak periods (e.g., morning showers).
Energy efficiency of DHW systems
Heat pump advantages: Heat pump systems can be 3-4 times more efficient than traditional electric boilers, thanks to the utilization of ambient thermal energy.
Minimizing heat loss:
- Tank insulation: Well-insulated storage tanks reduce heat loss, thus requiring less energy to keep the water constantly hot.
- Pipe insulation: Reducing heat loss from water pipes also improves system efficiency.
Use of water softener: Hard water can cause limescale build-up, damaging the system and reducing its efficiency. The use of a water softener may be essential.
Temperature monitoring: The tank temperature should be checked periodically to ensure it is not too low (to prevent the formation of legionella bacteria) or too high (to minimize energy loss).
Domestic hot water (DHW) systems play a central role in household comfort. Heat pump systems offer an energy-efficient alternative to traditional solutions, especially with well-insulated tanks and proper sizing. Regular maintenance, protection against limescale, and temperature control are crucial for long-term economy and efficiency.