scholarly journals Humidity-Sensitive Demand-Controlled Ventilation Applied to Multi-Unit Residential Building – Performance and Energy Consumption in Dfb Continental Climate

Author(s):  
Jerzy Sowa ◽  
Maciej Mijakowski

A humidity-sensitive demand-controlled ventilation system is known for many years. It has been developed and commonly applied in regions with an oceanic climate. Some attempts were made to introduce this solution in Poland in a much severe continental climate. The article evaluates this system's performance and energy consumption applied in an 8-floor multi-unit residential building, virtual reference building described by the National Energy Conservation Agency NAPE, Poland. The simulations using the computer program CONTAM were performed for the whole hating season for Warsaw's climate. Besides passive stack ventilation that worked as a reference, two versions of humidity-sensitive demand-controlled ventilation were checked. The difference between them lies in applying the additional roof fans that convert the system to hybrid. The study confirmed that the application of demand-controlled ventilation in multi-unit residential buildings in a continental climate with warm summer (Dfb) leads to significant energy savings. However, the efforts to ensure acceptable indoor air quality require hybrid ventilation, which reduces the energy benefits. It is especially visible when primary energy use is analyzed.

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6669
Author(s):  
Jerzy Sowa ◽  
Maciej Mijakowski

Humidity-sensitive, demand-controlled ventilation systems have been in use for many years in regions with oceanic climates. Some attempts have been made to apply this technology in Poland, which has a continental climate. This article evaluates the performance and energy consumption of such a system when applied in an eight-floor, multiunit, residential building, i.e., the virtual reference building described by the National Energy Conservation Agency (NAPE), Poland. Simulations using the computer program CONTAM were performed for the whole heating season based upon the climate in Warsaw. Besides passive stack ventilation, that served as a reference, two ventilation systems were studied: one standard and one “hybrid” system with additional roof fans. This study confirmed that the application of humidity-sensitive, demand-controlled ventilation in multiunit residential buildings in a continental climate (Dfb) led to significant energy savings (up to 11.64 kWh/m2 of primary energy). However, the operation of the system on higher floors was found to be ineffective. Ensuring consistent operation of the system on all floors required supplementary fans. The introduction of a hybrid mode reduced carbon dioxide concentrations by approximately 32% in the units located in the upper part of the building. The energetic effect in such cases depends strongly on the electricity source. In the case of the national energy grid, savings of primary energy would be relatively low, i.e., 1.07 kWh/m2, but in the case of locally produced renewable energy, the energy savings would be equal to 5.18 kWh/m2.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3876
Author(s):  
Sameh Monna ◽  
Adel Juaidi ◽  
Ramez Abdallah ◽  
Aiman Albatayneh ◽  
Patrick Dutournie ◽  
...  

Since buildings are one of the major contributors to global warming, efforts should be intensified to make them more energy-efficient, particularly existing buildings. This research intends to analyze the energy savings from a suggested retrofitting program using energy simulation for typical existing residential buildings. For the assessment of the energy retrofitting program using computer simulation, the most commonly utilized residential building types were selected. The energy consumption of those selected residential buildings was assessed, and a baseline for evaluating energy retrofitting was established. Three levels of retrofitting programs were implemented. These levels were ordered by cost, with the first level being the least costly and the third level is the most expensive. The simulation models were created for two different types of buildings in three different climatic zones in Palestine. The findings suggest that water heating, space heating, space cooling, and electric lighting are the highest energy consumers in ordinary houses. Level one measures resulted in a 19–24 percent decrease in energy consumption due to reduced heating and cooling loads. The use of a combination of levels one and two resulted in a decrease of energy consumption for heating, cooling, and lighting by 50–57%. The use of the three levels resulted in a decrease of 71–80% in total energy usage for heating, cooling, lighting, water heating, and air conditioning.


Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5541
Author(s):  
Alessandro Franco ◽  
Lorenzo Miserocchi ◽  
Daniele Testi

The paper analyzes and compares the perspectives for reducing the energy consumption associated to the operation of Heating Ventilation and Air Conditioning system for climatic control of large-size non-residential buildings. Three different control strategies are considered comparing the use of boiler and heat pumps as heating systems and analyzing the use of demand-controlled ventilation, operating on the effective occupancy of the building. The control strategies are applied to two different educational buildings with shapes representative of typical educational structures. The results of the analysis show how the energy consumption can be reduced up to 70%, shifting from the actual values of the energy intensity of over 300 kWh/m2 for year to values of less than 100 kWh/m2 per year. The significance of the energy savings achieved in such different buildings has led to the identification of a possible benchmark for HVAC systems in the next future years which could help reach the environmental targets in this sector.


2017 ◽  
Author(s):  
Behrang Chenari ◽  
Francisco Bispo Lamas ◽  
Adélio Rodrigues Gaspar ◽  
Manuel Gameiro da Silva

A significant amount of energy is being used by ventilation and air conditioning systems to maintain the indoor environmental condition in a satisfactory and comfortable level. Many buildings, either new or existing (throughout their renovation process) are subjected to energy efficiency requirements but these must not be in the expenses of indoor environmental conditions. For instance, indoor air quality (IAQ) has to be considered while improving energy efficiency, otherwise occupants might be exposed to inappropriate indoor environment.Demand-controlled ventilation (DCV) is a method that provides comfortable IAQ level with lowest energy use. In this paper, the main objective is developing a new CO2-based DCV strategy and simulating it using EnergyPlus. The IAQ and energy consumption associated to this strategy have been compared with the results of CO2-based DCV strategies previously developed by the same authors in another article. The comparison shows that the new strategy performs better, both in energy use and IAQ. The recorded energy savings ranged between 6-14% comparing with the previously developed strategies while IAQ slightly improved.


2018 ◽  
Vol 49 ◽  
pp. 00068 ◽  
Author(s):  
Piotr Lis

In the face of a constant increase in demand for energy, one of the important sources will be its saving and efficient use. The search for the greatest opportunities in this area should focus on the areas where the highest energy consumption occurs. The dominant role here is played by the communal and living sector, to the extent that it is the sub-sector of buildings with a majority share of residential buildings. The article presents the expected energy effects of measures reducing energy consumption for heating residential buildings in the whole country. The author used statistical data of the Central Statistical Office available in the database of this institution. These data were identified and searched for as suitable for the purposes of this article and were used as a basis for calculations and analyses. The calculations show that only thanks to simple actions such as improvement of thermal insulation of envelope components it is possible to reduce energy consumption for heating of residential buildings by over 70% in relation to the situation in 2011. The potential energy effect will also translate into an economic and environmental effect. Qualitative measures such as improving the performance of the heating and ventilation system of a building and/or changing the energy carrier will also reduce energy consumption for this purpose, but they are not the subject of this study.


Author(s):  
Hua Chen ◽  
Qianqian Di

To improve the applicability of water-cooled air-conditioners in the domestic sector, the development of a prediction model for energy performance analysis is needed. This paper addressed the development of an empirical model for predicting the operation performance and the annual energy consumption for the use of water-cooled air-conditioners. An experimental prototype was set up and tested in an environmental chamber in validating the empirical model. The predictions compared well with the experimental results. Furthermore, a high-rise residential building whole-year energy consumption simulation on applications of water-cooled air conditioners in South china was also analyzed. The results show 20.4% energy savings over air-cooled units while the increase in water-side consumption is 31.1%. The overall energy savings were estimated at 16.2% when including the additional water costs.


Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1912 ◽  
Author(s):  
Vasco Granadeiro ◽  
Margarida Almeida ◽  
Tiago Souto ◽  
Vítor Leal ◽  
João Machado ◽  
...  

This work addresses the effect of using thermochromic paints in residential buildings. Two different thermochromic paint types were considered: One that changes properties through a step transition at a certain temperature, and another that changes properties in a gradual/linear manner throughout a temperature range. The studied building was a two-floor villa, virtually simulated through a digital model with and without thermal insulation, and considering thermochromic paints applied both on external walls and on the roof. The performance assessment was done through the energy use for heating and cooling (in conditioned mode), as well as in terms of the indoor temperature (in free-floating mode). Three different cities/climates were considered: Porto, Madrid, and Abu Dhabi. Results showed that energy savings up to 50.6% could be reached if the building is operated in conditioned mode. Conversely, when operated in free-floating mode, optimally selected thermochromic paints enable reductions up to 11.0 °C, during summertime, and an increase up to 2.7 °C, during wintertime. These results point out the great benefits of using optimally selected thermochromic paints for obtaining thermal comfort, and also the need to further develop stable and cost-effective thermochromic pigments for outdoor applications, as well as to test physical models in a real environment.


2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Naim Jabbour

Data shows residential energy consumption constituting a significant portion of the overall energy end use in the European Union (EU), ranging between 15% and 30%. Furthermore, the EU’s dependency on foreign fossil fuel-based energy imports has been steadily increasing since 1993, constituting approximately 60% of its primary energy. This paper provides an analytical re-view of diverse residential building/energy policies in targeted EU countries, to shed insight on the impact of such policies and measures on energy use and efficiency trends. Accordingly, the adoption of robust residential green and energy efficient building policies in the EU has increased in the past decade. Moreover, data from EU energy efficiency and consumption databases attributes 44% of total energy savings since 2000 to energy upgrades and improvements within the residential sector. Consequently, many EU countries and organizations are continuously evaluating residential building energy consumption patterns to increase the sec-tor’s overall energy performance. To that end, energy efficiency gains in EU households were measured at 1% in 2000 compared to 27.8% in 2016, a 2600% increase. Accordingly, 36 policies have been implemented successfully since 1991 across the EU targeting improvements in residential energy efficiency and reductions in energy use. Moreover, the adoption of National Energy Efficiency Actions Plans (NEEACP) across the EU have been a major driver of energy savings and energy efficiency. Most energy efficiency plans have followed a holistic multi-dimensional approach targeting the following areas, legislative actions, financial incentives, fiscal tax exemptions, and public education and awareness programs and campaigns. These measures and policy instruments have cumulatively generated significant energy savings and measurable improvements in energy performance across the EU since their inception. As a result, EU residential energy consumption trends show a consistent decrease over the past decade. The purpose of this analysis is to explore, examine, and compare the various green building and energy-related policies in the EU, highlighting some of the more robust and progressive aspects of such policies. The paper will also analyze the multiple policies and guidelines across targeted European nations. Lastly, the study will assess the status of green residential building policies in Lebanon, drawing from the comprehensive European measures, in order to recommend a comprehensive set of guidelines to advance energy policies and building practices in the country. Keywords: Building Policies; Residential Energy Patterns; Residential Energy Consumption; Energy Savings


2013 ◽  
Vol 805-806 ◽  
pp. 1558-1561
Author(s):  
Zhen Hua Bao

Reducing the amount of outdoor air entering a space has distinct advantages for ventilation system. However, it often brings the consequence of depressing indoor air quality (IAQ). For laboratories, on average, the laboratory IAQ conditions of low TVOCs and low particulates permitted the substantial reduction of minimum air change rates. With many modern laboratories operating with fewer fume hoods and more energy-efficient equipment and lighting, the labs minimum air exchange rate requirement is often the dominant energy use driver. Current codes or specifications for laboratories ventilation system are the most straight forward approaches. They do not optimize a laboratory's ventilation rate, or verify whether the intended levels of safety and comfort have been achieved by the labs design. Demand controlled ventilation (DCV) can also avoid over-ventilation by providing outdoor air rates based on actual occupancy rather than on design occupancy or full occupancy.


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