Energy Efficiency Improvement Measures and Their Effect on Heating Energy Consumption and Indoor Climate: Case Study in Selected Latvian Kindergartens

Most of energy in buildings in the Baltic states is used for heating, and therefore thermal insulation of building envelope as well as replacement of old wooden frame windows for PVC ones, have recently become one of the most commonly applied measures for energy conservation. However, energy improvement should not compromise health and comfort of building occupants, especially in kindergarten environments where both children and facility personnel can spend up to 12 hours per day. This study investigates the effect of implemented energy efficiency improvement measures on heating energy consumption and indoor climate in kindergartens in moderate climate zone of Latvia. Measurements of carbon dioxide, air temperature and relative humidity were carried out in six kindergartens (old, renovated and new-built), and data regarding heating energy consumption as well as kindergarten characteristics and maintenance activities was collected via combination of field visits, record analysis and interviews. This field study showed that different types of building construction as well as ventilation strategies employed by kindergartens can cause substantial variations in indoor air quality and comfort. It was found that most of time temperature and relative humidity was kept in a comfort range in all facilities. Carbon dioxide concentrations exceeded 1000 ppm in 75% of kindergartens studied, with the highest (1356 ppm) measured in a renovated facility with the natural ventilation system. Thus additional insulation of external walls should be accompanied by installation of more efficient ventilation system (mechanical) to account for air tightness, since opening of windows itself cannot provide optimal conditions indoors. The specific heating energy consumption during the year 2010 in four of six examined kindergartens varied between 196 and 285 kWh/m2, while the municipality goal is to reach as low as 100 kWh/m2yr. Therefore to reduce energy consumption, further actions should be taken, e.g. including HVAC system retrofit and use of high-efficiency HVAC equipment

Buildings Total Energy Consumption as the Basis of Energy Certification

Buildings’ heat consumption certification scheme in Latvia exists since 2000. It is based on measured heat consumptions for the space heating and hot water supply corrected for the climatic conditions of particular year and number of inhabitants. With the support of EC LIFE program this system of buildings’ energy certification was successfully implemented in one medium size town of Latvia in 2002-2004. In order to comply fully with the requirements of the Directive 2002/91/EC on the energy performance of buildings the existing scheme is being modified to include full energy consumption of building that consists of heat consumption for space heating and hot water supply, gas consumption for cooking needs and electricity consumption. The paper presents analysis of the data on buildings full energy consumption gathered in Ogre town in 2003/2004. It gives new formula for the standardized annual specific energy consumption that includes also electricity and gas consumptions as well as the new rating scale. The paper for the first time shows buildings energy certification results made by the new scale in 2003/2004 and compares them with the certification results done earlier by the old scheme

Būvniecības siltumfizika ēku projektētājiem

Šis RTU Siltuma un gāzes tehnoloģijas katedras asistenta M.sc.ing. Anatolija Borodiņeca un profesora Dr.habil.sc.ing. Andra Krēsliņa darbs būtu jānosauc par metodiskajiem norādījumiem, atbilstoši mūsu augstākās izglītības tradīcijām. Kaut gan patiesībā ar tā iznākšanu ir sākts jauns posms Latvijas tehniskajā literatūrā. Tiek ieviesta tradīcija, kas jau desmitiem gadu ir lolota ASV un Kanādā, kur 1896. gadā dibinātā profesionālā inženieru savienība „American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE)” izdod pamācības (guide lines) par atsevišķu federatīvo būvnoteikumu un nacionālo standartu lietošanu

Profesors Dr. habil. sc. ing. Andris Krēsliņš : biobibliogrāfija

Rīgas Tehniskās universitātes profesora A. Krēsliņa biobibliogrāfija aptver laika posmu no 1959. līdz 2008. gadam

Energy Sector: Study and Training

Energy sector ; study and trainin

. Мероприятия по экономии энергии в вентиляционных системах животноводческих ферм

We analysed the possibilitiesfor the reduction of energy consumption using regenerative heat exchange devices. The optimal indoor air parameters in piggeries pursuant to zoo-hygienic requirements depend on pig's physiological condition, age and group

Impact of Indoor Climate on Energy Efficiency and Productivity in Office Buildings

Most of energy in buildings is used for creation of healthy and comfortable indoor environment, and therefore lately an increased attention has been directed towards optimization of operation of heating, ventilation and air conditioning (HVAC) systems. This paper presents graphic-analytical approach to investigate the impact of indoor climate on energy efficiency and productivity in office buildings. Thermodynamic analysis of air conditioning processes is performed using statistical data for outdoor air conditions in Baltic States. The proposed method enables estimation of additional energy expenses that are required to maintain the optimal temperature and humidity levels for maximal productivity. The study shows that it is not viable to maintain optimal indoor air condition throughout the entire year, thus the allowance for deviation of temperature and humidity should be considered during certain periods, especially in cold and humid climate. Results of this study could be further used for improvement of building norms and regulations regarding design and operation of HVAC systems

Energy Consumption and Employee Productivity Investigation with Respect to Profit in Office Buildings

Effects of indoor environmental quality on employee productivity and performance are well established in literature. However, further justification and quantification of costs for maintaining optimal indoor conditions for maximized employee productivity are necessary. This paper presents graphic-analytical approach to investigate the effects of indoor climate on energy consumption and productivity with respect to costs for maintaining optimal indoor air conditions in office buildings. Thermodynamic analysis of air conditioning processes is performed using statistical data for outdoor temperature and relative humidity. The economic evaluation is based on introduction of coefficients describing the price of heating and cooling energy and consumption of water, expressed as heat energy. Results are further plotted on Mollier (h-x) diagram confined with isolines of the levels for the combined energy consumption. Outdoor climate deviation from the optimal indoor air condition increases energy consumption and decreases the profit. Under the extreme outdoor conditions the air handling unit cannot maintain desired indoor temperature and humidity levels and employee productivity decreases, consequently leading to loss in total profit. The proposed approach can be used for optimization of operation of air handling equipment, and determination of maximum economically viable capacities of heating, cooling and humidification equipment, using profit as a criterion

Calculations of Energy Consumption in Ventilation Systems

Our investigation compare tradition ventilating system with mechanical ventilating in which can use heat and moisture exchangers. Utilization of outflow air heat raises efficiency of ventilating system, thus reduce operational costs for preparing of supply air. Both systems compare on necessary enthalpy for heating of inlet air. Various consumptions of thermal energy were calculated and compared in the course of the research during the heating season, using the climatological data about the repetition frequency of various outdoor air parameter combinations. The obtained data about the consumption of energy can be used in technical and economic assessments for the choice of optimal ventilation equipment and the supply air processing