Water Tanks

System Description

Storage tanks and water tanks in UNIVENTA product line up provide top quality at affordable prices. A Czech manufacturer with long-term experience is able to produce tanks of steel or stainless steel in volumes from 200 to 10,000 litres. In addition to standard installation types, these tanks can adapt to many different applications (different outputs location, etc.).

The standard range of tanks include:

Enamel tank heaters of hot water (HW) with two heating coils
Specially combined storage tanks FE AKU TV/SOL for HW flow heating and solar systems
Storage tanks FE AKU TV with a high-performance heat exchanger for HW flow heating (top-located)
Storage tanks FE AKU SOL with a high-performance heat exchanger for HW solar systems (bottom-located)
Storage tanks FE AKU ST without a heat exchanger

Other options:

production according to requirements
various structural modifications (outputs location, etc.).
manufacture of stainless steel tanks

Energy requirements for the preparation of HW is the sum of the primary energy requirement for heating of normal volume of drinking water, including loss energy in the heat source, HW tank, in the HW distribution system, and the energy requirement which needs to be supplied at the time between the water outlet (tap) opening and achievement of its design temperature.

Order product

The system should be designed so that:

the HW design temperature with thermal disinfection is 60 °C (more in "Thermal Disinfection", p.10),
the HW design temperature without thermal disinfection is 70 °C,
the maximum temperature difference between the outlet and return hole of the tank is maximum 5 K,
water of the design temperature runs from the water faucet within 30 seconds after the tap opening,
the heat loss - linear density of the pipeline heat flow does not exceed 8 W/m,
the heat loss of the tanks and storage tanks does not exceed the value according to ISO 12241 - Thermal insulation of technical equipment of buildings and industrial plants.

Legionella pneumophila bacteria are pathogenic hydrophobic microorganisms that colonize water and air-conditioning systems of buildings and their outbreak poses a serious health risk accompanied by various problems and respiratory diseases. These diseases include legionnaire's disease. Legionella bacteria are commonly found in watercourses, cooling towers, stagnant water, soil, and in the environment of water systems, hot water tanks, fittings, pipelines they are found in sediments and in the case of severe outbreaks in the form of biofilm.

Legionella bacteria pose a risk if they are dispersed into the air in the aerosol form (e.g. in taking shower) and are inhaled by humans with weakened immune systems, children, smokers, older people, etc. The disease manifests by similar symptoms as flu and can escalate into serious conditions such as acute atypical pneumonia. According to STN 83 0616 (Quality hot service water) the building operator is obliged to ensure the prescribed quality and temperature of water in the hot water system at each offtake point in compliance with the basic parameters of drinking heated water. The temperature at which the reproduction of Legionella microorganisms occurs is from 25 to 50 °C.

Solution:: HW tanks and the entire piping to the discharge point is therefore necessary to be periodically heated to a temperature at which the destruction of harmful Legionellaoccurs (heating time depends on the temperature of thermal disinfection from 5 to 15 minutes), followed by flushing at a temperature of above 60 °C. If the tank heating is not sufficiently ensured by a primary source, an electric heating coil/insert needs to be installed in the tank for that purpose. In the case of using the tank with HW flow heating there is no possible contamination (colonization) of Legionella bacteria because drinking water is heated up at the time of its actual consumption. However, the occasional thermal disinfection of the entire system is appropriate.