The essential role of the tank of a water heater is to be a water storage tank, and in this sense, to be constantly filled. The materials of manufacture of the tank are in particular steel, copper, plastic and composite.
Containing water, the tank is often protected from corrosion by enamel, baked, or by a mineral coating. Also, the weight of a container filled with water is not negligible; its installation requires special care, especially in wall or wall mounted tripod.
Which Tank To Choose?
The tank itself can be made from copper, which is particularly resistant to corrosion but is a thermal conductor, steel, stainless steel, or plastic. The steel tanks are usually covered with enamel (slip) mainly composed of silica. Besides the paint, the container can be covered with zinc and food resin, or thermoplastic materials.
Tanks of small capacity can be made of plastic. The tanks made of plastic resistant to pressure, they are indeed reserved for water heaters of low volumes.
The composite tank consists of synthetic materials reinforced with glass fibers. It is resistant to temperature and corrosion as effectively as the steel tank but has the advantage of being particularly light.
The tank is generally cylindrical or curvilinear with two flanks curved on both sides in the form of a cap. One of these funds (lower in the case of a vertical tank), has a base on which is the resistance and the thermostat. Two pipes pierce the shell, one short which allows the arrival of cold water, the long one which enables the departure to of hot water and whose point of drawing is always in the upper part of the tank.
The tank contains hot water but is always placed in a more relaxed environment. In this way, the tank continually loses calories in the atmosphere, which represents a loss of energy and a considerable financial loss. To limit this heat transfer, the tank is equipped with heat insulation, usually polyurethane foam highly insulating, which is injected between the tank and the jacket of the water heater.
A tank can be installed vertically, horizontally or on the ground. Attention, a water heater must be expressly installed in the position for which it was planned. Some water heaters can be installed vertically or horizontally, but they have been designed for. A tank with a capacity of less than 100L requires only one hanging bracket on the wall, while larger containers (up to 200L) require two. Water heaters above 200L cannot be installed in a wall position. This variety of sizes and installations makes it easy to adopt an electric water heater to environmental or space constraints.
A Vertical Or Horizontal Water Heater?
Even if both models exist, in case of hesitation, if the location allows it, always favor the installation of a vertical tank.
Indeed, a horizontal electric water heater, by its geometry, is much less efficient than a vertical model: the phenomenon of stratification of hot water, that is to say, formation of two layers distinct depending on the temperature of the water, is much less critical/ higher and on more extensive exchange surfaces (elongated). Mixtures are more essential with water entry turbulence, resulting in less hot water during racking compared to a vertical model.
For this reason, it is necessary to choose a horizontal tank only under the condition of facing constraints of space and installation, making it impossible to install a vertical tank.