Many countries have developed their national regulations on requirements for one or more types of recycled water, to some extent depending on how these waters are used. Similar recommendations have been made by some international organizations.

What should be hygienists attitude to using recycled water? The approach should be unprejudiced, but critical, based on the precautionary principle. It can not be expected in the future that hygienists will particularly encourage water recycling in the Czech Republic, especially in contact with people and food.

The change of Z1 ČSN 75 5411 was processed mainly due to the incorporation of water meter shaft requirements without the necessity for persons entry (so-called microshaft) into this standard. Current version of ČSN 75 5411 of April 2006 did not mention the water meter shaft without the necessity for entry of persons, and there were doubts as to whether such water meter shafts on the water connections are permissible.

The paper deals with the experimental determination of heat losses of reservoirs (hot water storage tanks, heaters, heat reservoirs). It shows how the thermal loss of the tank itself, determined by the correct procedure in accordance with the standard, can be different from the loss of the reservoir connected to the thermal system.

Models where the only solution is either a central cleaning or a balancing basin (the toilets are flushing) are long overdue even in Europe, just after several lines. For example, Germany officially withdrew from the effort to drain the whole country centrally in the 1990s when it judged that such behavior was both non-economic and non-ecological and "unsustainable".

The article deals with the analysis of a possible solution of a non-energy residential building. The analysis shows what energy sources help to achieve a zero balance of non-renewable primary energy and what is not. In the contribution, the investment solution and the real operating costs of the energy-zero residential building compared to the current solution are shown for the selected solution and a simple payback period is set.

The article presents a concrete example of a real operational problem with the use of so-called double-walled hot water heaters. The example is aimed at destroying the reservoir of the construction system tank in the tank due to a malfunction of the operating mode.

Now is the time when even in the Czech Republic we have to save water. In our households we can use grey water for flushing toilets, used water reuse for irrigation, etc. But we must not forget the risks associated with gray water re-use.

The change of Z1 ČSN 75 5411 was mainly processed due to the incorporation of water meter shaft requirements without the need to enter persons (so-called microshaft) into this standard. The current version of ČSN 75 5411 of April 2006 did not mention the water meter shaft without the necessity of entry of persons, and there were doubts as to whether such water meter shafts on the water connections are permissible.

At the time of changing climatic conditions and reducing the quantity of raw material it is necessary to start saving water and raw materials. To achieve this target it is good to separate wastewater at the source and using of no-mix toilets. Czech legislation is not yet adapted to this alternative treatment of waste water.

The paper is focused on the issue of the pipeline networks dilatation. From the perspective of the designer, it is a very simple and well-documented issue. However, as is shown in the article, if the basic requirements are not met when designing the pipeline networks, the results can be quite fatal.

The unused chimney flue or strong wall of the chimney body offers the possibility of using it for conducting pipes etc. It is a prerequisite to keep the flue gas safety and operating mode of other installations. The article highlights the important factors of a possible decision.

The definition of what is a common part of a residential building is essential especially when modifying the building structures and eliminating defects that affect both a common part and residential units. How common parts are defined affects who finances the modifications and reconstructions of such structures and parts. The definition of common parts is based on the new Civil Code (No. 89/2012 Coll.) and on the already abolished Act on Ownership of Housing (No. 72/1994 Coll.).

The article presents a concrete example of a real operational problem with the use of so-called double-walled hot water heaters resulting from the heat-technical properties of such water heaters.

The parameters and characteristics obtained from the laboratory test are used to compare products in terms of performance and efficiency. The results also serve for the correct design and evaluation of the year-round behavior of the element built into the entire thermal system.

The article deals with the definition of consumer and basic heating rate. It is recommended to use the ratio of 50 % basic nad 50 % consumer rate or 60 % consumer and 40 % basic if individual heat meters are used.

For individual payment calculation for hot water we need an invoice from heat supplier with the total cost of the property in CZK and with the amount of GJ. In addition, we need the water supplier invoice, which includes the total cost of water and sewerage. For the calculation then we need water consumption from water meters.

Paper presents the analysis of water heating by a heat pump and influence of tank size, temperature setting and heat pump selection on annual use of electric energy.

The article deals with the issue of safety valves installation for water heaters. Neglecting of the installation conditions often causes damage to the installed appliance, or (as shown in the paper) loss on the water and sewer charges in the case of a safety valve installed in the water heater safety group.

The article summarizes overview of ways to secure water heaters in Europe, which became the basis for design of integrated methodology applied in the Czech Republic.