Interview with eng. Nikolay Kontantinov, manager of "Termosyst" Ltd. in the new issue 2 of the GRADAT Magazine

"TERMOSYST" Ltd. applies the so-called. system engineering with taking full responsibility for the proper functioning of air conditioning and ventilation systems and achieving the set design parameters (fullresponsibility company). The company uses the most innovative technologies (VRV and HYDRONIC) of DAIKIN, providing quality, reliability and installation flexibility. With its 27 years of experience in the design, supply and installation of this type of air conditioning systems, the company is an undisputed leader in the sector and has already installed over 1200 VRV systems with a total heating capacity of 40 MW.

Eng. Konstantinov, what are the tendencies in HVAC construction of modern office buildings?

- The correct choice of air conditioning and ventilation systems is crucial for achieving an optimal microclimate in modern offices. In this type of buildings it is mandatory that all HVAC projects are modular and flexible, because the different rentees, especially from the IT sector require individual engineering solutions to achive a comfortable working athmosphere with the minimum exploration costs. That is why we need an experienced design team, which we have. The latest rrends for office buildings are looking to minimization of energy costs and the working characteristics of the building installations, adequate devision of the energy according to the consumption of the separate parts of the building as well as all inside installations. In Europe, it has already been imposed as a mandatory so-called BIM method of design, which "Termocyst" has been using for 25 years, and in recent years we have been working a lot with the BIM technology.

"Termosyst" designed and implemented the HVAC systems of office buildings 1 and 2 in Garitage Park? What are the challenges of working at work?

- In 2018, our company was selected by the investors on the basis of the proposed alternative solutions for the systems for heating, ventilation and air conditioning. Thanks to the achieved excellent results, we are already working on the implementation of HVAC systems in the remaining two office buildings - 3 and 4. On the basis of BIM design, we have developed visual installation with visual modeling. It is combined with hydraulic modules for utilization of waste heat for production of hot (high temperature - up to 750C, and low temperature - up to 550C), and in summer with reversal of the cycle - and cold water, in parallel with the air conditioning of buildings.

The waste heat is also used for the underfloor heating of the reception floor and underground garages, as well as for the floor. Modular three-pipe air conditioning systems allow the microclimate to be controlled at any point in the buildings according to the needs of the individual users, without the need for manual switching to heating or cooling mode. The excellent technological capabilities of the DAIKIN VRV IV system have allowed three remote facades to be covered with one machine per floor, which significantly reduces energy costs. In addition, in combination with the revolutionary VRT (variable refrigerant temperature) technology, we have provided an additional 28% savings in the process of both cooling and heating of the office buildings. The ventilation system of office buildings 1 and 2 has been developed and implemented on a modular principle. The solution is the best possible - with enthalpy recuperative heat exchangers, which combine "recuperation - heat transfer" with moisture transfer.

They are small and compact, low energy consumption and are very suitable for large work rooms. Their use prevents air drying. Their installation does not require the presence of machine rooms, as it is carried out directly on the suspended ceiling by means of small air ducts integrated in the facade elements. With the application of this type of modular ventilation systems it is not necessary to make large verticals in the building for access to fresh air from the roof, as well as the installation of a large number of fire dampers.

The office has 2 special  requirements, prompted by its owner - WMWare.

- It was a great pleasure for us and it is an honor to work with WMWare - a world leader in the IT industry. It is important that the parameters of the HVAC systems already designed by us to be increased several times in accordance with the specific specifications of their activity. There were many high demands on the microclimate in the working premises in terms of temperature, humidity, acoustics. We have conducted a study of the noise characteristics of the air ducts, based on the design of special shock absorbers.

We achieved excellent results thanks to the work with BIM technology up to the level of detail of the machines: air ducts, cable glands, plugs. We work with millimeter accuracy so that they can be assembled in the ceilings, without compromising the interior design of the offices and facades of the buildings. For fist time we made special calculations of the heating and climatisation results with the most modern technology, used also in the USA - namely HEAT BALANCE. This method analyses very accurately each hour (in comparison with other methods such as RTS for example) the activity of the consumtion in one building during the exploatation, measuring also the accumulation.  The program is in DWG format and is developed by DAIKIN. WMWare is currently expanding its office space and in building 3, where it has 4 more floors.

What is the innovative method of application for the ventilation systems of office buildings?

- The construction of ventilation systems in the office buildings of Garitage Park needed the search for a fast and technological way to install them. For this purpose, "Termosyst" contacted the Swedish company Lindab - a leading manufacturer and supplier of elements for air duct systems, for the application of the patented air duct system Lindab Safe Click. It is based on the "Lego assembly" principle and meets the highest standards for airtightness - class D. In our production base in Plovdiv is installed the first computer machine in our country for the production of spirally wound air ducts from strip steel, cutting size and compatibility of Safe Click systems. The advantage is that they are pre-prepared and can be mounted directly on the respective site.

Air duct systems are accompanied by 3D diagrams with printed location codes of each element and technical quantitative specification. It is not necessary to cut the spiro ducts to the required installation length on site. In some functional units of the complex (sports hall, swimming pool, gym) air-conditioning plants of DAIKIN are installed, which allow precise maintenance of the supply air temperature based on heat carrier "hot" and "cold" water. In the underground garages is installed a ventilation system based on "jet" fans mounted on the ceiling, ie. without air ducts. The system is developed through computer simulation in two modes: normal and with included smoke extraction. Before starting the installation of all engineering networks, "Termosyst" took on the difficult task of coordinating all
installation systems in office buildings in 3D environment in order to eliminate conflict points during their installation.

What other large-scale objects are you working on at the moment?

- In the process of engineering construction on the HVAC system at the IVIS TECHNOLOGY CENTER in Plovdiv. We also offer a three-pipe VRV system with the ability to transfer heat from the affected areas to such a shortage. We are planning HVAC systems for the balneological hotel "Diana Mar 2" in Pavel Banya and for the current hotel in Buolevard "Maria Luyza" in Plovdiv.