Energy saving in construction requires no small expenditures — from 5 % to 10 % of the cost of the construction object. Nevertheless, the introduction of energy-saving technologies at the stage of construction will not only increase the level of comfort in the premises, but will also help to further save energy resources and reduce the cost of their use. The implementation of measures to improve energy efficiency during construction, increases the cost of construction in comparison with traditional technologies of construction of buildings. However, a detailed economic calculation shows that the costs incurred at the stage of the pay off within 5–8 years. This happens at the expense of savings during the operation of houses and payment of utilities. In addition, due to energy savings in construction, you can simultaneously create a more comfortable environment for people.
Key words: energy efficiency, energy saving, engineering systems.
Energy efficiency is the rational use of energy resources. In energy efficient facilities, less energy is consumed, but the level of energy supply of the building remains the same. If we compare this term with energy conservation, the difference is not saving energy, but its efficient use, not to the detriment of consumers.
Optimization example. Lighting control.
Measures taken to reduce electricity consumption in the office building.
The first phase involves modernizing the lighting system. Traditional ballasts for fluorescent lamps are replaced by electronic ballasts. This reduces the energy consumption of the fluorescent lamps by about 30 %.
To further optimize energy consumption, a constant light function is additionally introduced. The goal is to keep the workplace at a constant 500 lux. A special sensor constantly monitors the level of light in the room, taking into account the intensity of natural light, sun protection systems (blinds, roller shutters, etc.), and then the data obtained are analyzed by the dimmer, which then adjusts the light output of luminaires. This method of control saves from 28 to 66 % of electricity used for lighting.
Finally, lighting can be controlled by monitoring the presence of people in the room with a presence detector. If people are out and no one has manually turned off the lights, they can be turned off automatically. The automatic control of lighting based on the presence of people in the room provides an additional savings of 13 %.
Optimization example. Blind control. Blind control for optimum use of daylight.
By controlling the blinds, you can regulate the amount of natural light entering the room. Thus, there is a direct correlation between the control of artificial light and the control of blinds. If it gets too dark in the office when the blinds are closed, the light is switched on, to compensate for the lack of light. But the lighting system consumes more energy during the day, when there is natural light available. A more effective solution is to automatically adjust the angle of the blinds to the position of the sun.
The blinds open just enough to allow enough daylight into the room. With reflective louvres, it is possible to diffuse the light to the ceiling and prevent glare. The combined use of such a solution with the function of maintaining a set level of light makes it possible to save considerable amounts of energy. According to the results of the aforementioned studies, automatic louver control and constant level of illumination plus occupancy related lighting control, can offer potential savings of up to 40 % compared to compared to the manual control of the lighting system.
Optimization option. Blind control to maintain an optimal microclimate.
Closed blinds on the facades on the south side of the building during the summer prevent the rooms from heating up, thereby saving energy that may be needed to cool the working areas. In winter, the opposite is true. At this time of year, as much solar heat as possible should enter the building, which leads to savings in energy used for heating the rooms.
In both cases, it is necessary to link the control of the microclimate with the presence of people in the room. As long as someone is working in the room, priority should be given to controlling the blinds depending on the natural light. This applies in particular to PC-based workplaces, school rooms and conference rooms.
Example of optimization. Heating, ventilation, air conditioning.
Practical experience shows that a 1 °C decrease in room temperature can reduce heat consumption by 6 %. If the room temperature is lowered by 3 °C when the room is unoccupied, the heating energy savings will be 18 %. Since the temperature generally changes slowly, this type of control is only useful if the room is unoccupied for a long period of time.
If fans or fan heaters are used to control room temperature and air quality fans or fan coils can be controlled via KNX with a fan coil activator (FCA/S).
ABB i-bus® KNX technology offers extensive optimization possibilities in new buildings and renovations by connecting all engineering systems in a single network.
The calculations on which the European standard EN 15232 is based convincingly confirm this fact, demonstrating the potential savings in thermal energy.
Thermal energy saving is ensured by controlling the room temperature using a central timer and visualization system.
Blind control has received positive feedback from teachers and students as the use of automatic shading has eliminated the need for unnecessary heating of the rooms, which resulted in a noticeable increase in comfort.
In order to ensure a favourable climate throughout the flat during the winter period, it is possible to
The heat consumption of each heated room (individual room) can be controlled on a room-by-room basis to ensure a pleasant microclimate in the entire apartment during the winter. This can be achieved by
Thermostatic valves (thermostats) must be installed in the radiators. By installing thermostats on the radiators the following can be achieved heat consumption by a further 5 to 10 %.
Optimization option. Ventilation.
— Air recirculation systems. It is a mixing of exhaust and supply air in order to increase its temperature during the cold season. This allows you to reduce the cost of heating in winter. In addition, recirculation helps to stabilize air distribution during cold and warm seasons;
— Air recuperation systems. They allow you to heat the cold supply air from the air that is removed from the room. Mixing does not occur;
— The use of fans with the use of dead zones. This approach allows, firstly, to ensure smooth regulation of the fan frequency, secondly, to avoid overuse of electricity when starting electric motors and, finally, to reduce the noise level of ventilation systems and energy consumption of the system as a whole.
In addition, it is possible to use such energy-saving technologies in construction:
— The use of smart home systems and other automation. They regulate the operation of equipment depending on the temperature outside and inside the house. The use of intelligent heating control systems can make a huge contribution to saving energy for space heating. You need to install temperature sensors and adjust the operation of the devices according to their values. At the same time, it is recommended to allow for external control of the system (via the internet) and the possibility to specify the priority of the heating circuits;
— Reduction of heat losses by using more efficient radiators. The most economical and energy efficient heating systems are those with the lowest fluid temperature. Underfloor heating is best suited for this. Or a combination of this type of heating with modern radiators. They have a large contact surface with the air in the room;
— Use of high efficiency heating equipment. Boilers with forced ventilation and electric ignition systems are used to increase energy efficiency and reduce the amount of fuel used for heating. And also models with a large heat exchanger and condenser. They can store surplus energy and use it for space heating;
— The use of clean energy. At present, the most promising in terms of energy efficiency are wood and waste heaters, heat pumps and solar heaters.
References:
- EN 15232–1:2017 on «Energy efficiency in buildings — Influence of Building Automation and Control and Building Management».
- GOSTR 54862–2011. Energy efficiency of buildings. Methods for determining the impact of automation, management and operation of a building
- The Law of the Republic of Kazakhstan dated 13 January 2012 No. 541-IV «On Energy Saving and Energy Efficiency Improvement»
- Ensuring energy efficiency of buildings through technology https://www.tesli.com/upload/iblock/b21/abb_i_bus_knx_energy_efficiency.pdf#:~:text=Европейский %20стандарт %20EN %2015232 %20(«Энергетическая,по %20энергетическим %20характеристикам %20зданий %202002 %2F91 %2FEС
