The following contributions, which deal with this problematic, consider the impact of high heat resistance of the walling on the thermal comfort and the design of heating ventilations systems, which are still perceived, as it is the case in buildings with classical walling, therefore, to have lower thermal resistance. For instructions to formulate the effect of walling on the thermal comfort and technical equipment, a general comparison of both the following cases is made, which is simply called building with high thermal resistance of external walls for a low-energy house, and a building with classical walling parameters (e.g. housing estate from the past) as a standard house. The articles are not of exact technical nature and deal with regularly updated dependencies and sometimes refer to previously applicable legal provisions.

Examples of projects in Energy Performance Contracting
First two projects by the Energy Performance Contracting were prepared in the Czech Republic in 1993. From that time about 200 projects were implemented. The investment for the projects footed up to the total amount about 3 billion CZK. The highest number of the projects was implemented in school buildings with investment from one till ten million CZK. A lot of projects were implemented in buildings of healthcare service. On examples of implemented projects are described main features of the EPC projects for hospitals (the biggest project with investment over 100 million CZK), for schools (mostly smaller projects) or for more buildings in one public tender (municipalities or regions).

The EPC and its relations with other activities in connections with energy savings
In 2006 the Directive 2006/32/EC on energy end-use efficiency and energy services was adopted for the support of international activities on development of energy services. The obligation of each EU member state is prepare and submit to the Commission the Energy Efficiency Action Plan in roughly three years cycles. In relation to the Directive other activities were supported by EC under the Intelligent Energy Europe Programme, as projects: the Concerted Action on the ESD, ChangeBest, EESI or Pernament. Internal Czech initiative is under activities of Czech ESCOs, which are preparing Association of energy services companies.

The attenuation of sound wave with bends is mostly used in the design of noise walls, curtains and barriers along ways with intensive traffic (roads, rail and tram). Noise reduction from stationary sources with curtains is less common because it is always better to place the noisy device in the machine hall. This is then ventilated through a system with big enough dimensions so as to absorb sound, which then blocks the source of sound and the fan noise. Let's look at some specific installations seen in this context as well as calculations of the sound attenuation bend.

The article deals with the issue of unwanted condensation of water vapour on internal surface of building structures. Building and physical conditions of surface condensation of water vapour is analysed. It discusses possibilities of technical solutions leading to elimination of the mentioned negative phenomenon – change of use, adjustment of peripheral structures, reaching the required parameters of internal air by natural ventilation or through air-conditioning.

Advantages of the EPC methodology in comparison to other solutions

EPC methodology has a lot of advantages in comparison to other solutions on reconstruction of energy systems. The most important feature is assumption of risks, which customer would have to solve. The most important adoptable risk is guarantee for the savings. Unique feature of the EPC is the same motivation for the ESCO and for the customer, both to invest money by the most effective way (efficient quality equipment) and to reach as high savings as possible. It is very appealing that the ESCO is able to assure financing of the project. The customer needs not spend the investment during implementation of the energy efficient measures and he pays it back during the investment during the contract duration from saved operational costs.

Specific features of the EPC in the Czech Republic

The Energy Performance Contracting was introduced in the Czech Republic in 1992. From that time the EPC methodology was developed enough in the field of documentation for public tendering process and also in the field of text of contracts for the energy services provision. Unfortunately the state support of EPC project development is in the Czech Republic very weak. Nevertheless the situation is from ESCOs effort and interest of customers very good. By number of the EPC projects and size of the projects is the Czech Republic in Europe on the top position, including Germany, France, UK, Austria and Sweden.

Windows, as fillings of peripheral orifices in the structure of buildings, are a construction product, which either must be tested or verified for their compliance with the various Czech regulations and standards. One of the most important criteria that window structures must meet is the one prescribed by ČSN 730540-2 Thermal Protection of Buildings from April 2007 The compliance of the inner surface temperature factor with the standard ČSN 730540-2 must be verified separately for each orifice filling structure. So far, there are no universally applicable rules that determine which edge of glazing units can be applied to with structure. The area of the glazing joints is among the riskiest parts of the whole structure, and that is why two basic design rules were derived in order to provide an increase the internal surface temperature in that area.

More than 15 years TZB-info is focused to perspective equipment for building services with priority in heating. During this period the main question: "how to heat" shifted to question: "how to reduce heat loses". For example France is planning for new buildings only passive standard, and begining 2050 only so-called quasi-zero buildings. In Czech Republic one of significant impulses is subsidy program Zelená úsporám (Green for savings). Technical solutions are widely known in professional community, unfortunately high investment cost and long payback time are the main barriers for broader expansion of the solutions. Folowing article is the first from a serie focused to long time planing of reduction of energy consumption in the Czech Republic. From two ways - to prospect new energy sources or to reduce energy consumption - the second needs no to destroy another villages or towns.
How can heating for Czech homes be assured while at the same time get rid of the dependence on dirty coal and Russian gas? This is answered by the scholarly study by the DUHA movement – Clean Heating. The solution is based on a combination of investments on home insulation, solar collectors and biomass heating plants. Very important are the new standards for developers and provisional supply of coal from the Bílina mine. The calculations are based on those from the Pačes Commission. There are many opportunities. Increasing the energy efficiency of builings – i.e. insultaions – and the heating potential from renewable sources represent more than 300 million gigajoule. This surpasses the total current heating consumption of Czech homes. The possibilities of insulating Czech homes are also five and a half times higher than the controversial expansion of the coal mines around Most, which is linked with a further devastation of the North Bohemian landscape and the demolition of towns.

This article extends the article "Ventilation with heat recovery in flat - yes or no?" and it is concerning with pressure forced ventilation with electric heating coil. This unit includes ventilator, which sucks the external air in from the façade. The electric heating coil with the power of 250 W preheats the external air which is distributed to the rooms with the air distribution system. Nowadays there are a lot of these units on the market that differ in air volume and heating power. The aim of this article is to investigate whether this unit ensures good air quality and what are the costs. The paper was made within the framework of the R&D project performed by the experts in the company EkoWATT, Czech Republic. R&D project VAV-SP-3g5-221-07 is supported by the Ministry of Environment.

Author offers practical best practices, leading to significant savings in the preparation of hot water, ensuring the required quantity of hot water, temperature and elimination of microbiological risks.

The article explains the principle of heat recovery and the basic categories of heat recovery units used in HVAC systems. It describes the advantages and disadvantages of individual heat recovery systems and their fitness for purpose.