Efficient use of existing building systems and technologies provides maximum comfort at low energy cost. The quality-to-price ratio is achieved through proper analysis and combination of architecture and building systems. The use of computational software for building energy simulations is the best option for this.
Heat pump systems can supply heating, domestic hot water and cooling of a building. Powered by electricity, these systems are highly efficient and can supply heating or cooling energy at drastically lower price compared to standard heating appliances. There are several types of heat pumps.
Heat pump systems types Installations for heating, cooling and domestic hot waterOption, which is most affordable. Investment for it is financially most advantageous. It is also independent of the existence of geothermal water or terrain properties, which makes it preferable and easy for installation and control.
Closed geothermal system, which relies on the constant soil temperature after the second meter in depth and the heat exchange is performed by antifreeze, circulating in the ground loop (horizontal or vertical). Most effective type of heat pumps.
System, which uses geothermal energy. It is an open system that is directly supplied by a source of underground water with a constant temperature - drilling, well, drainage water, etc.
Ventilation systems can be used for heating, cooling and ventilation to provide good indoor climate in terms of СO2, air age and air humidity. Modern systems are equipped with heat exchangers, allowing the exhaust air to transmit its energy to the incoming air, which provides significant energy savings in heating or cooling mode.
Solar shading systems should provide sun protection mostly during summer, when its energy is not needed for heating a building. They can be controlled by schedule, internal temperature, solar radiation on glass surface, etc.
Passive measures Natural, free energy which can be usedIn addition to the energy efficiency systems already listed (powered by electricity), it is also necessary to consider the passive measures (which do not require electrical energy) for heating, cooling and ventilation. Such may be:
Direct sunlight penetrates the premises during winter and reduces the need for additional heating during the day.
Thermal mass of the construction determines if it is possible energy to be accumulated which later can be released, contributing to energy savings from heating and cooling.
These factors are important for optimal use of solar energy in the winter. The closer to sqare the plan of the building is, the less energy it would needs for heating and cooling.
These are covers, balconies, blinds and other elements which are of such size, shape and location that allow the sun to penetrate during winter but protect from direct sunlight during summer, when the sun is high.
Effective use of energy is an objective that can only be achieved through complex solutions.
Combination of active and passive strategies is determined by energy design - computer analysis using software simulating the indoor climate and energy consumption of the building.
Strategies for design of one building The importance of reasonable designQuality construction takes into account environmental factors and eliminates those that have a negative impact. What is the meaning of an efficient heating and cooling system if supplied energy "leaves" the building through thermal bridges that had to be avoided at the design stage? Following principles is important to be taken into account:
Good insulation properties of external building elements. Their U-value should be U ≤ 0.15 W/m²K. Current minimum requirements in Bulgaria are U = 0.28 W / m²K for walls, U = 0.40 W / m²K for floors and U = 0.25 W / m²K for roofs. Windows thermal transmittance coefficient should be ≤ 0.80 W/m²K (combined for glazing and frames) and glazing solar factor > 50%. Requirements in Bulgaria allow a thermal transmittance coefficient of U = 1.40 W / m²K.
Without thermal bridges in the construction of the building. In Bulgarian building regulations, excessive losses of thermal bridges are allowed, which is contrary to the principles of energy efficient construction. The term refers to heat conducting connections in the construction and façade of a building through which the heat "leaks" moving in the direction to the smallest thermal resistance. Example: Well-insulated external wall is intersected by a non-insulated reinforced concrete slab. In the contact zone, a thermal bridge is formed through which the inner surface is cooled, i.e. heat is lost, and in addition to heat losses, condensation conditions are created and consequently there is a risk of mold inside the room.
It is related to the inability of the outside air to infiltrate inside the building and vice versa. All the infiltration should be carried out by means of a ventilation system which allows its controlling, respectively controlling of heat losses.
A high percentage of energy recovered by the ventilation system - should be over 80%. The efficiency of fans in the ventilation system should also be with a value of near ≤ 0.5 W/m³/h.
Complete construction of a building in the center of Old Sofia, Bratya Miladinovi Street. Client: "Urban Stay" Ltd.
Innovation and cutting-edge technology in every element of the building - from geothermal wells providing energy-efficient heating, cooling and air conditioning to smart-home systems for automating security, notification, access control and more. The interior itself is a whole new page in the interior design of spaces.
The aparthotel has an exceptional quality of workmanship, high class materials, equipment and the idea "less means more" in its most sophisticated implementation! CITY-EURO exceeded the expectations of the demanding foreign investor, so that future visitors can enjoy the undeniable advantages of a modern, extraordinary in design and function, building.
Execution of the rough construction of an innovative residential building in Vitosha district, Prof. Georgi Zlatarski Street. Client: AKMI Ltd.
CITY EURO has completed the rough construction of QHome "The Key to a Better Life", the first residential building in Bulgaria certified under the EDGE sustainable/green building standard. QHome is an energy-efficient residential project that offers a concept of living in harmony with nature. The project is distinguished by the use of a geothermal cooling and heating system, made possible by heat exchange with the ground. The technology, also called a ground source heat pump, provides savings on monthly utility bills of up to 60%.
With a built-up area of 4945m², including 55 homes and 55 parking spaces, and with its location in one of the most preferred areas of Sofia, QHome has the ambition to offer the standard we need to lead a better life.
Residential and office buildings in regulated plot VII - 289, 256A, Pavlovo - Buxton, Investor: BUILD SYSTEMS BULGARIA Ltd.
Residential and office buildings in regulated plot VII - 289, 256A, Pavlovo - Buxton, Investor: BUILD SYSTEMS BULGARIA
"CITY-EURO" is a contractor of Roofing, waterproofing and tinsmith works, Cement screeds and pavements, Plumbing works and Thermal insulation and plaster on facades.
Investor: Municipality of Slivnitsa
Contract 2007 CB16IPO006-2009-1-150 Establishment and development of social infrastructure (Budget line 6 Investments) by IPA Cross border Bulgaria – Serbia 2007-2013, Investor: Municipality of Slivnitsa
Comprehensive construction of a modern office building. Client: "SDG SMART OFFICE" Ltd.
Scale, energy and sophisticated architecture in unity! 14000 m2 of total floor area, distributed in 11 above-ground and 2 underground floors and numerous challenges throughout the construction process failed to discourage the CITY EURO team! We started with a contract for the rough construction, subsequently, when every square inch of the building structure had passed through the mind or hands of our people, we took over as coordinating contractor and a significant part of the finishing works. The result is a magnificent office building that has brought together virtuoso design, technological innovation and first class equipment to provide comfort and confidence for the businesses that occupy it.
Comprehensive construction of an administrative building with offices, shops, and underground garages - Tsarigradsko Shosse Boulevard, 4th kilometer. Investor: BUILD SYSTEMS BULGARIA Ltd
Office building with trade area and underground garages - "Tsarigradsko Shose" blvd., 4-th kilometer, Investor: BUILD SYSTEMS BULGARIA Ltd.
Q-center was a professional challenge, especially from a constructive point of view, because the mix of one main body and three low bodies is a combination of highly irregular in plan and high-rise buildings with very complex shape facades. This necessitated the building separation with seismic joints in four separate blocks and using a mixed structure of beams and columns composed of frames and reinforced concrete walls and cores.
The precise execution, the rhythmical and tight organization plus the saturation with sufficient equipment and qualified personnel led to the logical result - a timely and quality completion, regardless of the additional difficulty that was created by the location of the site: the roundabout on 4-th kilometer, "Tsarigradsko Shose" blvd. - the junction with one of the trafic in the capital.
Machine laid cement sanding screed and specialized construction works on the territory of Bulgaria's largest shopping center - THE MALL, "Tsarigradsko Shose" blvd.
Machine laid cement sanding screed and specialized construction works on the territory of Bulgaria's largest shopping center - THE MALL - "Tsarigradsko Shose" blvd.
CITY EURO is one of the main contractors of a machine layed cement-sand screed from tender for THE MALL - "Tsarigradsko Shose" blvd", namely: CARREFOUR, NEW YORKER, SPIDER, Marc O`Polo, ESPRIT, ZARA, PRETTY SHOP, MODESTAMENTE, HUMANIC, INTERSPORT, ADIDAS, PUMA, DOUGLAS, SEPHORA, BEAUTY ZONE, La Coste ect. In most of the commercial areas, as required by the investors, a cement-sand screed, significantly exceeding the technical characteristics of BDS National Standart for this type of construction product, was layed.
Complex of residential buildings "BRIGHT LIGHT" I and "BRIGNT LIGHT" II . Investor: BUILD SYSTEMS BULGARIA Ltd.
Complex of residential buildings "BRIGHT LIGHT" I and "BRIGNT LIGHT" II . Investor: BUILD SYSTEMS BULGARIA Ltd.
"CITY-EURO" is the main contractor of Roofing, waterproofing and tinsmith works, Thermal insulation and mineral plaster on facades, Cement mortars and pavements, Water and sewage works, Hydro and thermal insulation on balconies and terraces, floor screeds and concrete flooring.
Complete construction of two passive houses - an example of the higher standard in low-energy construction.
Passive buildings have a high level of thermal insulation, a minimum of thermal bridges and low infiltration, to achieve which they use the heat inflows from solar energy and internal accumulation, as well as the recycling of the thermal energy of the air exhausted from the ventilation.
Modern systems
Precise control
Building energy design
