Domestic Hot Water Supply Systems

Vocabulary flashcards on domestic hot water supply systems, methods of water heating, system components, distribution systems, and standards from the 1999 NPC.

Domestic Hot Water Supply

The supply of hot water for domestic use based on the need for personal hygiene and washing in order to remain healthy and safe.

Localized Water Heating

The practice of heating water near the point of use by installing individual heating units directly at specific locations (such as sinks, showers, or dishwashers) rather than centrally heating water for an entire building.

Centralized Hot Water System

A system that provides hot water to an entire building or facility from a single central source, heating water in a large storage tank or boiler and distributing it through a piping network.

Instantaneous Water Heater

Also known as a tankless or on-demand water heater, a device that heats water directly as it flows through the unit without requiring a storage tank.

The Up-Feed and Gravity Return System

A hot water distribution system commonly used for small residential houses and some industrial applications, providing constant circulation and economically returning unused hot water to the system.

Overhead Feed and Gravity Return System

A hot water distribution system commonly used in buildings with extreme heights, relying on the thermal expansion of hot water to rise to the top and gravity to return it to the storage tank.

Pump Circuit System

A hot water distribution system that utilizes a mechanical device, such as a centrifugal pump, to circulate hot water in large buildings or structures with inefficient natural circulation.

Range Boiler

A small hot water tank generally constructed from copper or stainless steel.

Storage Boiler

A large hot water tank generally constructed from heavy-duty stainless steel.

Table 4.4 Hot Water Consumption

A reference table from the 1999 NPC specifying hot water consumption rates in gallons per person per hour for various building types.

Table 4.5 Working Load of Hot Water

A reference table from the 1999 NPC outlining the average working load percentages of hot water for different building classifications.

Centrifugal Pump (Hot Water System)

A mechanical pump containing impellers whose rotary motion maintains an even flow of hot water throughout a building distribution network.

Residential Hot Water Consumption Rate

$10\,\text{gallons per person per hour}$ according to Table 4.4 of the 1999 NPC.

Apartments and Residences Working Load

$35\%$ average working load according to Table 4.5 of the 1999 NPC.