The different types of attic water tanks include traditional storage tanks and tankless water heaters. Traditional models may be powered using different types of fuel, which allows homeowners to choose the solution which is most economical for their lifestyles. This type of equipment is usually installed by a professional contractor or service man, and can often reduce the amount of energy consumed by a home.
The term water tank may be used to refer to any type of water storage and heating device that is used to provide hot water to a household. This type of equipment is traditionally placed in utility rooms, garages, and landscaping sheds away from the home to prevent damage in the event of the tank becoming rusted or leaky. As the water travels the distance from the heater to the house and through the interconnecting network of pipes, it tends to lose some of its heat and causes some cold water loss as the user waits for the hot water to arrive. Attic water tanks allow the unit to be placed inside the home close to those plumbing fixtures which tend to use the most hot water. Using the equipment in this way allows hotter water to be delivered faster, using less energy and less water than those tanks which are installed in locations away from the main areas of the home.
The most commonly type of attic water tanks installed are those which use storage tanks. This type of tank uses an internal heating element to heat cold water, which is then stored for later usage. Once a hot water tap is turned on inside the house, the hot water flows to that area, and new cold water is heated to replace that which is being used. Storage tank water heaters may be fueled using electricity, natural gas, or solar power, all of which are suitable for use in the attic.
These models are available in a wide range of sizes, depending on the water capacity needs of the home. Large homes, with multiple family members who may need access to hot water frequently throughout the day, need larger capacity tanks or multiple tanks. The feasibility of whether this style of water heater can be installed in an attic depends on the storage capacity of the attic and the size of the tank.
Most storage capacity water tanks, regardless of their fueling mechanism, require a ceiling clearing distance between four and eight feet (1.21 meters to 2.43 meters). The storage tank itself, once adequate clearance has been determined, can be mounted on exposed ceiling joists. An overflow pan may be placed beneath the tank in case of rust or leakage. Homeowners may prefer to use a large pan that builders specify to prevent water from overflowing the pan and damaging the ceiling beneath.
Gas fueled attic water tanks require access to an outside ventilation shaft to operate properly. Excess heat and fumes are vented away from the tank and the home through an open shaft, which can usually be placed in the roof of the house. Solar powered attic tanks can route power directly from roof mounted panels to the storage tank using a minimum amount of cable and piping.
Flash attic water tanks use the least amount of water of all types of heaters. This electric or natural gas powered unit may also be known as a tankless water heater, because the system does not store heated water. Once a user has turned on a hot water faucet, the system pulls from its energy source to immediately heat only that water which is presently being used. The unit may be installed on a wall in the attic that has access to electricity or a gas line, and does not require an overfill drip pan or the storage capacity of a standard sized water tank.