Point-of-use water heater is a small heater, designed as the mini storage tank or tankless unit, used for water heating at the point of service, often installed under the kitchen sink. These heating units are very popular in residential applications or offices as they provide delivery, without taking up a lot of space.
Point-of-use water heaters are not designed for large
volume of hot water but to serve low volume
fixtures as lavatory sinks, small apartments, cottages, garages and
where there is no
central heating (distant sinks),
including mobile homes. Point-of-service water heater is usually used
for one application only, as the
individual units at each point-of-use
or in combination with large heaters.
The main advantage of point of use heating is avoiding long pipe run from the central heating system and distant heaters, which makes it perfect for small jobs like dish-washing or hand-washing.
If there is a remote sink that is not served by a tank-type or tankless water heater, like the bathrooms of the office buildings or service stations, point-of-use water heater is the right solution.
Also, another reason for installing these small heaters is if you live in the big house and have a distant sink where it takes too long to receive hot water. Here, point-of-use hot water heater is often used as the great alternative to heat the water at the point of service, so you can benefit by eliminating the wait time and on energy saving.
As the point-of-use water heater is installed right where it is needed, under the sink for example, hot water will be available instantly. This is the reason why they are also called instant or under-the-sink water heaters.
As said before, there are two types of point-of-use water heaters: mini-storage tank type with the capacity of 2.5 gallons up to 30-gallon, and tankless appliances with the continuous supply. Tankless point of use heaters are rated by the number of gallons per minute unit provides, while for tank-type based on the tank capacity.
Good example of electric mini-tank type is the Ariston from Bosch, while for electric tankless, Stiebel Eltron. AquaStar 1000P-NG from Bosch is the example of the gas fired point of use heater.
Small in size, point of use water heaters are equipped with some great components; to prolong the heaters life, increase the performance, and efficiency, save on energy, an even automatically to control the system.
Most of the point of use heaters are equipped with the metal tank, but there are also models with the plastic tank, like Marathon point-of-use water heater, that doesn't corrode.
Heaters are usually equipped with only one screw-in style heating element, which transfers the heat directly and efficiently to the surrounding water.
Storage tank-type units are protected from the corrosive effects of hot water using the ceramic/glass coating, combined with the anode rod.
Fully automatic control is achieved by using the surface-mount thermostat with the ECO, installed for safety in excess temperature situations.
Smaller units use 120 V and are supplied with the cord which you can plug it into any standard outlet, while 240 V models include a junction box for different but easy installation.
With its space-saving design, point-of-use water heater is perfect for installation in the area with the limited space. These electric heaters can be mounted almost anywhere; in the kitchen and bathrooms under the sink, inside the cabinets of apartments and condos, in camps and recreational properties, hanging on the wall, in stores, offices and other places as the wash station.
The size of the point of service heater you need depends on the area where it will be installed and the availability of the power supply. Smaller size units are mainly used for jobs like hand-washing, while larger models with the higher flow are used for dish-washing, shaving and even showering.
Always use manufacturer recommendations and their manual when installing the point-of-use water heater. You can install the heater as the independent unit or as part of the in-line installation, together with the other heaters, tankless for example.
The can be installed directly at the sink, on the cold supply line and as close as possible to the hot tap, which eliminates the need for recirculating lines and pumps. Some models can be installed horizontally while other vertically.
Heaters are usually mounted on the wall, with the provided brackets. There are available in 120 V and 240 V option. If you choose units with a higher voltage it is common to find that they will provide more gallons per minute of hot water.