It appears there might be a slight typo in your question, as the common term related to hot water provision in HVAC is DHW, not DWH. DHW stands for Domestic Hot Water.
In the context of Heating, Ventilation, and Air Conditioning (HVAC) systems, DHW refers to Domestic Hot Water. This is the hot water used for everyday purposes within a building, such as showering, washing hands, and cleaning.
While not strictly part of the core temperature or air quality control functions of HVAC, the systems that heat and distribute domestic hot water are often integrated or closely related to the overall building services, including HVAC. Therefore, DHW systems are frequently discussed and designed alongside HVAC systems.
How DHW Relates to HVAC Systems
Integrating DHW systems with HVAC can lead to increased energy efficiency and simplified building management. For instance, some HVAC systems might share heating sources (like boilers) with the DHW system.
According to the provided reference, Domestic Hot Water (DHW) is provided in DesignBuilder Detailed HVAC through DHW loops, Water heaters, Water outlet groups and Water outlet components. This illustrates how DHW is modeled and managed within HVAC design software, highlighting its inclusion as a key part of the building's mechanical services design.
Components of a DHW System
A typical DHW system involves several key components:
- Water Heater: The appliance that heats the cold water. This could be a tank-based heater, tankless (on-demand) heater, solar thermal system, or even part of a larger boiler system shared with space heating.
- Storage Tank (Optional): Stores heated water for later use.
- Piping: Distributes hot water from the heater to the points of use.
- Circulation Pump (Optional): Used in some systems (especially larger ones or those with long pipe runs) to constantly circulate hot water to outlets, providing hot water instantly.
- Fixtures/Outlets: Taps, showerheads, appliances (like dishwashers or washing machines) where the hot water is used.
- Control System: Manages the water temperature and operation of the heater and pump.
The reference specifically mentions how these are represented in DesignBuilder:
- DHW Loops: Represent the piping network carrying the hot water.
- Water Heaters: Model the equipment that heats the water.
- Water Outlet Groups and Water Outlet Components: Represent the points where hot water is drawn, allowing simulation of usage patterns.
Why is DHW Important in HVAC Design?
Considering DHW during HVAC design is crucial for:
- Energy Consumption: Heating water is a significant energy load in most buildings. Designing efficient DHW systems is vital for overall building energy performance.
- System Integration: As mentioned, heating sources can be shared, impacting the design and sizing of central plant equipment.
- Load Calculation: The energy required for DHW contributes to the total building energy load, which must be accounted for in overall HVAC and energy system design.
- Thermal Comfort: While direct space conditioning, access to readily available hot water also contributes to the occupants' comfort and health.
In summary, while 'DWH' isn't a standard HVAC term, the concept of DHW (Domestic Hot Water) is closely related to and often integrated with HVAC systems, covering the heating and distribution of hot water for typical household or building use.
