Electric domestic hot water design

Hot water is generated in a number of ways for domestic delivery. Electric hot water generation for domestic delivery is a popular option for modern homes and building projects. These units vary in size and cost. Early in the design phase, consult a qualified MEP engineer to ensure you select the method and unit to generate the desired amount of hot water for your building. They will be able to help you make the correct selection before construction begins.

Having an MEP engineer involved early on also means they will be able to help you spot other potential problems in your design, like omitting an adequate mechanical room to house the desired electric hot water unit. Often the MEP (mechanical, electrical, plumbing) parts of the building design are overlooked or thought to be not as important as the structure design. The MEP aspects of your building are integral and need to be designed by qualified engineers.

Electric Hot Water Heaters

Electric Water Heaters for domestic delivery are generally used for small-scale point of use and have a localized design. Hot water heaters are used to supply homes, apartments and other structures with hot water for use in laundry, showers, bathrooms, sinks, and janitorial basins. For single family homes, you will generally use one 50 gallon hot water heater to supply the entire home. This size is usually adequate for the needs of the occupants. Smaller water heaters are used in single-family apartments and condos.

Other instances when electricity is used to generate hot water can be on an even smaller scale. One application would be when you have a modular trailer on a site that only needs hot water at one extraction point, like a sink in the kitchen area or in the bathroom.

A job trailer on a construction site would not normally have a shower in it so the amount of hot water needed is quite less than a modular home. With this application, you would use a wall mounted hot water heater that allowed for a single point of extraction. It would be fed directly from the water line and would be plugged into a properly fitted/powered outlet for the locale.

How do Electric Hot Water Heaters Work?

The general idea of an electric hot water heater is that energy of electricity is used to heat up water stored in a tank in the unit. Usually, the unit is hardwired or plugged into a 220-volt circuit. Using the electric current provided by the power supply, the design of the unit makes the current pass through heating elements that are electrical resistant. There are usually two heating elements. These are distributed through the tank, generally at the bottom and at the middle of the tank.

Using a thermostat, the power is then delivered to the elements in the tank of the hot water heater. A thermostat is a switch that is designed to measure the temperature of the water. By using a thermostat in the design, the hot water heater is able to function independently, cycling on and off as necessary to maintain the correct amount of hot water and keep the water at a set temperature. They usually have a dial in the design to allow for users to change the desired maximum temperature as needed.

The temperature of the water dictates the state of the hot water heater. As the temperature of the water drops, the switch in the thermostat closes to allow the electric current to flow to heat the water, and then it opens again once the temperature of the water hits the preset limit.

When an occupant opens a hot-water tap, the cold water enters the tank through what the industry calls the dip tube. The drop in water temperature from the cold water triggers the thermostat and the element then kicks in. When the user turns off the tap, the heating elements will continue to carry the current until the temperature of the thermostats equalizes.

Things to consider

When selecting the type of hot water heater and the number of units you need, an MEP engineer will be able to help you make the right selections. One of the first steps will be to identify the number of fixtures and water extraction points. This will help inform the capacity of the hot water heater needed or if you need to look into installing multiple smaller units to meet the need.

The nature and use of your building will play a huge factor in type and number of hot water heaters you need. The number of occupants that are usually in the building during any given day will also make an impact on the hot water quantity demand. Meeting that demand with the appropriate supply will be a priority.

Identifying the potential power supply options will also make an impact on how you deliver the hot water to the occupants. In addition to the size of the building and potential demand, you may be limited in options dependant on the utilities available to your project site. If you have electricity available, it still might not be the right choice for your project depending on demand needs.

A qualified MEP engineer will be able to help you assess all of the factors needed to make these decisions. Engaging an engineer early on in the design process will help you alleviate potential project headaches and future problems in the building for future owners.

ELECTRIC DOMESTIC HOT WATER DESIGN

Mechanical - HVAC Engineering

Comfortable

Energy-Efficient

Built to Last

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