Estimation of Infiltration Rate (ACH Natural) Using Blower Door Test and Simulation

Junghyon Mun; Jongik Lee; Minsung Kim

doi:10.3390/en14040912

Estimation of Infiltration Rate (ACH Natural) Using Blower Door Test and Simulation

Energies ◽

10.3390/en14040912 ◽

2021 ◽

Vol 14 (4) ◽

pp. 912

Author(s):

Junghyon Mun ◽

Jongik Lee ◽

Minsung Kim

Keyword(s):

Input Data ◽

Evaluation Method ◽

National Laboratory ◽

Measurement Data ◽

Infiltration Rate ◽

Lawrence Berkeley National Laboratory ◽

Apartment House ◽

Infiltration Rates ◽

Heating And Cooling ◽

Cooling Loads

One of the primary factors for generating heating and cooling loads in apartment houses is infiltration. However, the evaluation method for infiltration rates has not been well established for the apartment houses in Korea. The existing method measures air change per hour of a house at 50 Pa (ACH50) and divides it by the leakage–infiltration ratio, N = 20, as suggested by the Lawrence Berkeley National Laboratory (LBL). In this study, a method to evaluate the average infiltration rate of an apartment house using blower door tests and simulations is suggested. Six sets of blower door tests were conducted, and the measurement data were used to estimate the flow coefficients and pressure exponents of all infiltration routes. The values were used as the input data for EnergyPlus to calculate the natural air change per hour values (ACHn) of two households. The calculated ACHn values were compared to the ACHn values calculated using the LBL method, which is commonly used in Korea. Through this process, the limitations of applying the LBL method to calculate the ACHn values in Korea were investigated. The results show that investigating the proper leakage–infiltration ratio is required for Korea. The method suggested in this study can be used to determine the proper leakage–infiltration ratio for apartment houses.

Download Full-text

Final Environmental Assessment and Finding of No Significant Impact: Construction and Operation of the Molecular Foundry at Ernest Orlando Lawrence Berkeley National Laboratory Berkeley, California

10.2172/823488 ◽

2003 ◽

Author(s):

Keyword(s):

Environmental Assessment ◽

National Laboratory ◽

Lawrence Berkeley National Laboratory

Download Full-text

An Overview of CCD Development at Lawrence Berkeley National Laboratory

Experimental Astronomy ◽

10.1023/b:expa.0000004341.11906.bf ◽

2002 ◽

Vol 14 (2) ◽

pp. 83-89 ◽

Cited By ~ 7

Author(s):

Steve Holland

Keyword(s):

National Laboratory ◽

Lawrence Berkeley National Laboratory

Download Full-text

Towards Sustainable Energy Retrofitting, a Simulation for Potential Energy Use Reduction in Residential Buildings in Palestine

Energies ◽

10.3390/en14133876 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3876

Author(s):

Sameh Monna ◽

Adel Juaidi ◽

Ramez Abdallah ◽

Aiman Albatayneh ◽

Patrick Dutournie ◽

...

Keyword(s):

Energy Consumption ◽

Energy Use ◽

Energy Savings ◽

Residential Buildings ◽

Residential Building ◽

Simulation Models ◽

Water Heating ◽

Heating And Cooling ◽

Space Cooling ◽

Cooling Loads

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.

Download Full-text

Comparison of Factorial and Latin Hypercube Sampling Designs for Meta-Models of Building Heating and Cooling Loads

Energies ◽

10.3390/en14020512 ◽

2021 ◽

Vol 14 (2) ◽

pp. 512

Author(s):

Younhee Choi ◽

Doosam Song ◽

Sungmin Yoon ◽

Junemo Koo

Keyword(s):

Latin Hypercube Sampling ◽

Building Design ◽

Gain Coefficient ◽

Design Parameters ◽

Latin Hypercube ◽

Heating And Cooling ◽

Factor Design ◽

Heating Loads ◽

Cooling Loads ◽

Interest In Research

Interest in research analyzing and predicting energy loads and consumption in the early stages of building design using meta-models has constantly increased in recent years. Generally, it requires many simulated or measured results to build meta-models, which significantly affects their accuracy. In this study, Latin Hypercube Sampling (LHS) is proposed as an alternative to Fractional Factor Design (FFD), since it can improve the accuracy while including the nonlinear effect of design parameters with a smaller size of data. Building energy loads of an office floor with ten design parameters were selected as the meta-models’ objectives, and were developed using the two sampling methods. The accuracy of predicting the heating/cooling loads of the meta-models for alternative floor designs was compared. For the considered ranges of design parameters, window insulation (WDI) and Solar Heat Gain Coefficient (SHGC) were found to have nonlinear characteristics on cooling and heating loads. LHS showed better prediction accuracy compared to FFD, since LHS considers the nonlinear impacts for a given number of treatments. It is always a good idea to use LHS over FFD for a given number of treatments, since the existence of nonlinearity in the relation is not pre-existing information.

Download Full-text

On the interpretation of annual oscillations in 32Si and 36Cl decay rate measurements

Scientific Reports ◽

10.1038/s41598-021-95600-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

S. Pommé ◽

K. Pelczar ◽

K. Kossert ◽

I. Kajan

Keyword(s):

Decay Rate ◽

Solar Neutrino ◽

National Laboratory ◽

Neutrino Flux ◽

Measurement Data ◽

Brookhaven National Laboratory ◽

Decay Rates ◽

Dew Point ◽

Annual Variations ◽

Set Up

AbstractThe 32Si decay rate measurement data of Alburger et al. obtained in 1982–1986 at Brookhaven National Laboratory have been presented repeatedly as evidence for solar neutrino-induced beta decay. The count rates show an annual sinusoidal oscillation of about 0.1% amplitude and maximum at February–March. Several authors have claimed that the annual oscillations could not be explained by environmental influences on the set-up, and they questioned the invariability of the decay constant. They hypothesised a correlation with changes in the solar neutrino flux due to annual variations in the Earth-Sun distance, in spite of an obvious mismatch in amplitude and phase. In this work, environmental conditions at the time of the experiment are presented. The 32Si decay rate measurements appear to be inversely correlated with the dew point in a nearby weather station. Susceptibility of the detection set-up to local temperature and humidity conditions is a likely cause of the observed instabilities in the measured decay rates. Similar conclusions apply to 36Cl decay rates measured at Ohio State University in 2005–2012.

Download Full-text