Domestic Hot Water System

Supplying DHW by Gas Water Heater

DHW systems can be basically divided into two main parts:

the DHW heater where the DHW is heated from cold potable water, and
the in‐house DHW distribution system, i.e., pipes connecting the heat.

Standards stipulate the following requirements for all DHW systems:

Hygiene – DHW should be delivered without increased risk for bacterial growth.
Comfort – DHW should be delivered in reasonable time, with the desired temperature and without unwanted fluctuations in temperature.

Standards stipulate that the DHW should be delivered to every DHW tap with a minimal temperature of 50°C, but the temperature can drop to 45°C during peak situations. However, it varies depending on the DHW use (tapping types).

TYPES OF WATER HEATERS:

Conventional storage water heaters offer a ready reservoir (storage tank) of hot water
Tankless or demand-type water heaters heat water directly without the use of a storage tank.
Heat pump water heaters move heat from one place to another instead of generating heat directly for providing hot water.
Solar water heaters use the sun’s heat to provide hot water.
Tankless coil and indirect water heaters use a home’s space heating system to heat water.

Selecting a Gas Water Heater

When selecting a new water heater for your home, choose a water heating system that will not only provide enough hot water but also that will do so energy efficiently, saving you money.

SELECTION CRITERIA:

Fuel type, availability, and cost: The fuel type or energy source you use for water heating will not only affect the water heater’s annual operation costs but also its size and energy efficiency. See below for more on selecting fuel types.
Size: To provide your household with enough hot water and to maximize efficiency, you need a properly sized water heater. Visit the pages on different types of water heaters (linked above) for more on sizing.
Energy efficiency: To maximize your energy and cost savings, you want to know how energy efficient a water heater is before you purchase it. Visit the pages on different types of water heaters (linked above) for more on estimating energy efficiency.
Costs: Before you purchase a water heater, it’s also a good idea to estimate its annual operating costs and compare those costs with other less or more energy-efficient models. Visit the pages on different types of water heaters (linked above) for more on estimating costs.

Contact

2 Ali Amin St., Nasr City, Cairo, Egypt