Download or read book TWO NEW DUCT LEAKAGE TESTS written by and published by . This book was released on 1998 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two variations on the tests for duct leakage currently embodied in ASHRAE Standard 152P (Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems) are presented. Procedures are derived for calculating supply and return duct leakage to/from outside using these new variations. Results of these tests are compared with the original ones in Standard 152P on the basis of data collected in three New York State homes.
Download or read book Duct Leakage Testing written by John Diem and published by ESCO Press. This book was released on 2015-05-01 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: To comply with the International Energy Code, most states now require duct testing for both new construction and retrofit. Duct leakage testing provides an in-depth understanding of duct leakage testing procedures, methods of expressing results, and terminology. Building Science is the study of a building's interaction between the structure and its components. A structure's occupants, mechanical systems, and the surrounding outdoor environment all play a role in the performance of a building. Duct Leakage Testing covers: * Duct leakage testing methods or total leakage. * Leakage to the outside using a duct pressurization tester. * Modified blower door subtraction methods.
Download or read book HVAC Air Duct Leakage Test Manual 2nd Ed written by Smacna and published by . This book was released on 2012-01-02 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Duct and Envelope Testing written by Erik Rasmussen and published by ESCO Press. This book was released on 2015-01-01 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: To comply with the International Energy Code, most states now require duct testing for both new construction and retrofit. Duct and Envelope Testing provides an in-depth understanding of envelope and duct leakage testing procedures, methods of expressing results, and terminology. This five-section manual provides an understanding of the terminology and building science affecting energy efficiency. The tools and testing procedures used to evaluate a building's envelope and duct systems are covered in detail. The manual provides the methods for expressing and recording envelope or duct leakage test results and explains what the numbers mean to the home owner and local code officials. The manual contains a worksheet for each section.
Download or read book FIELD EVALUATION OF IMPROVED METHODS FOR MEASURING THE AIR LEAKAGE OF DUCT SYSTEMS UNDER NORMAL OPERATING CONDITIONS IN 51 HOMES written by Paul W. Francisco and published by . This book was released on 2003 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Duct leakage in forced-air distribution systems has been recognized for years as a major source of energy losses in residential buildings. Unfortunately, the distribution of leakage across homes is far from uniform, and measuring duct leakage under normal operating conditions has proven to be difficult. Recently, two new methods for estimating duct leakage at normal operating conditions have been devised. These are called the nulling test and the Delta-Q test. Small exploratory studies have been done to evaluate these tests, but previously no large-scale study on a broad variety of homes has been performed to determine the accuracy of these new methods in the field against an independent benchmark of leakage. This sort of study is important because it is difficult in a laboratory setting to replicate the range of leakage types found in real homes. This report presents the results of a study on 51 homes to evaluate these new methods relative to an independent benchmark and a method that is currently used. An evaluation of the benchmark procedure found that it worked very well for supply-side leakage measurements, but not as well on the return side. The nulling test was found to perform well, as long as wind effects were minimal. Unfortunately, the time and difficulty of setup can be prohibitive, and it is likely that this method will not be practical for general use by contractors except in homes with no return ducts. The Delta-Q test was found to have a bias resulting in overprediction of the leakage, which qualitatively confirms the results of previous laboratory, simulation, and small-scale field studies. On average the bias was only a few percent of the air handler flow, but in about 20% of the homes the bias was large. A primary flaw with the Delta-Q test is the assumption that the pressure between the ducts and the house remain constant during the test, as this assumption does not hold true. Various modifications to the Delta-Q method were evaluated as possible improvements. Only one of these modifications provided improved results. This modification requires measuring the duct pressure relative to the house at either every pressure station within the Delta-Q test or at the extremes of the house pressure range involved in the Delta-Q test. If the pressures are only measured at the extremes, then calculated pressures at the other pressure stations are obtained via interpolation. Using these pressures reduced the bias in the Delta-Q test by about one-third.
Download or read book Development of a New Duct Leakage Test written by and published by . This book was released on 2001 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Duct leakage is a key factor in determining energy losses from forced air heating and cooling systems. Several studies (Francisco and Palmiter 1997 and 1999, Andrews et al. 1998, and Siegel et al. 2001) have shown that the duct system efficiency cannot be reliably determined without good estimates of duct leakage. Specifically, for energy calculations, it is the duct leakage air flow to outside at operating conditions that is required. Existing test methods either precisely measure the size of leaks (but not the flow through them at operating conditions), or measure these flows with insufficient accuracy. The DeltaQ duct leakage test method was developed to provide improved estimates of duct leakage during system operation. In this study we developed the analytical calculation methods and the test procedures used in the DeltaQ test. As part of the development process, we have estimated uncertainties in the test method (both analytically and based on field data) and designed automated test procedures to increase accuracy and reduce the contributions of operator errors in performing field tests. In addition, the test has been evaluated in over 100 houses by several research teams to show that it can be used in a wide range of houses and to aid in finding limits or problems in field applications. The test procedure is currently being considered by ASTM as an update of an existing duct leakage standard.
Download or read book Field Evaluation of Improved Methods for Measuring the Air Leakage of Duct Systems Under Normal Operating Conditions in 51 Homes written by and published by . This book was released on 2003 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt: Duct leakage in forced-air distribution systems has been recognized for years as a major source of energy losses in residential buildings. Unfortunately, the distribution of leakage across homes is far from uniform, and measuring duct leakage under normal operating conditions has proven to be difficult. Recently, two new methods for estimating duct leakage at normal operating conditions have been devised. These are called the nulling test and the Delta-Q test. Small exploratory studies have been done to evaluate these tests, but previously no large-scale study on a broad variety of homes has been performed to determine the accuracy of these new methods in the field against an independent benchmark of leakage. This sort of study is important because it is difficult in a laboratory setting to replicate the range of leakage types found in real homes. This report presents the results of a study on 51 homes to evaluate these new methods relative to an independent benchmark and a method that is currently used. An evaluation of the benchmark procedure found that it worked very well for supply-side leakage measurements, but not as well on the return side. The nulling test was found to perform well, as long as wind effects were minimal. Unfortunately, the time and difficulty of setup can be prohibitive, and it is likely that this method will not be practical for general use by contractors except in homes with no return ducts. The Delta-Q test was found to have a bias resulting in overprediction of the leakage, which qualitatively confirms the results of previous laboratory, simulation, and small-scale field studies. On average the bias was only a few percent of the air handler flow, but in about 20% of the homes the bias was large. A primary flaw with the Delta-Q test is the assumption that the pressure between the ducts and the house remain constant during the test, as this assumption does not hold true. Various modifications to the Delta-Q method were evaluated as possible improvements. Only one of these modifications provided improved results. This modification requires measuring the duct pressure relative to the house at either every pressure station within the Delta-Q test or at the extremes of the house pressure range involved in the Delta-Q test. If the pressures are only measured at the extremes, then calculated pressures at the other pressure stations are obtained via interpolation. Using these pressures reduced the bias in the Delta-Q test by about one-third.
Download or read book Ein j ngst entdecktes Massengrab in Leipheim Landkreis G nzburg und der Umgang mit den Kriegstoten vor 1800 written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Duct Leakage Repeatability Testing written by and published by . This book was released on 2014 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques for duct leakage using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards. The three duct leak measurement methods assessed in this report are the two duct pressurization methods that are commonly used by many practitioners and the DeltaQ technique. These are methods B, C and A, respectively of the ASTM E1554 standard. Although it would be useful to evaluate other duct leak test methods, this study focused on those test methods that are commonly used and are required in various test standards, such as BPI (2010), RESNET (2014), ASHRAE 62.2 (2013), California Title 24 (CEC 2012), DOE Weatherization and many other energy efficiency programs.
Download or read book HVAC Air Duct Leakage Test Manual written by Sheet Metal and Air Conditioning Contractors' National Association (U.S.) and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Alternative Procedure to Home Energy Rating System Rater Nonresidential Duct Leakage Test Verification written by Joe Loyer and published by . This book was released on 2017 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book HVAC Air Duct Leakage Test Manual written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Error Analysis for Duct Leakage Tests in ASHRAE Standard 152P written by and published by . This book was released on 1997 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents an analysis of random uncertainties in the two methods of testing for duct leakage in Standard 152P of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). The test method is titled Standard Method of Test for Determining Steady-State and Seasonal Efficiency of Residential Thermal Distribution Systems. Equations have been derived for the uncertainties in duct leakage for given levels of uncertainty in the measured quantities used as inputs to the calculations. Tables of allowed errors in each of these independent variables, consistent with fixed criteria of overall allowed error, have been developed.
Download or read book Evaluation of the Repeatability of the Delta Q Duct Leakage Testing TechniqueIncluding Investigation of Robust Analysis Techniques and Estimates of Weather Induced Uncertainty written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The DeltaQ test is a method of estimating the air leakage from forced air duct systems. Developed primarily for residential and small commercial applications it uses the changes in blower door test results due to forced air system operation. Previous studies established the principles behind DeltaQ testing, but raised issues of precision of the test, particularly for leaky homes on windy days. Details of the measurement technique are available in an ASTM Standard (ASTM E1554-2007). In order to ease adoption of the test method, this study answers questions regarding the uncertainty due to changing weather during the test (particularly changes in wind speed) and the applicability to low leakage systems. The first question arises because the building envelope air flows and pressures used in the DeltaQ test are influenced by weather induced pressures. Variability in wind induced pressures rather than temperature difference induced pressures dominates this effect because the wind pressures change rapidly over the time period of a test. The second question needs to answered so that DeltaQ testing can be used in programs requiring or giving credit for tight ducts (e.g., California's Building Energy Code (CEC 2005)). DeltaQ modeling biases have been previously investigated in laboratory studies where there was no weather induced changes in envelope flows and pressures. Laboratory work by Andrews (2002) and Walker et al. (2004) found biases of about 0.5% of forced air system blower flow and individual test uncertainty of about 2% of forced air system blower flow. The laboratory tests were repeated by Walker and Dickerhoff (2006 and 2008) using a new ramping technique that continuously varied envelope pressures and air flows rather than taking data at pre-selected pressure stations (as used in ASTM E1554-2003 and other previous studies). The biases and individual test uncertainties for ramping were found to be very close (less than 0.5% of air handler flow) to those found in for the pressure station approach. Walker and Dickerhoff also included estimates of DeltaQ test repeatability based on the results of field tests where two houses were tested multiple times. The two houses were quite leaky (20-25 Air Changes per Hour at 50Pa (0.2 in. water) (ACH50)) and were located in the San Francisco Bay area. One house was tested on a calm day and the other on a very windy day. Results were also presented for two additional houses that were tested by other researchers in Minneapolis, MN and Madison, WI, that had very tight envelopes (1.8 and 2.5 ACH50). These tight houses had internal duct systems and were tested without operating the central blower--sometimes referred to as control tests. The standard deviations between the multiple tests for all four houses were found to be about 1% of the envelope air flow at 50 Pa (0.2 in. water) (Q50) that led to the suggestion of this as a rule of thumb for estimating DeltaQ uncertainty. Because DeltaQ is based on measuring envelope air flows it makes sense for uncertainty to scale with envelope leakage. However, these tests were on a limited data set and one of the objectives of the current study is to increase the number of tested houses. This study focuses on answering two questions: (1) What is the uncertainty associated with changes in weather (primarily wind) conditions during DeltaQ testing? (2) How can these uncertainties be reduced? The first question is addressing issues of repeatability. To study this five houses were tested as many times as possible over a day. Weather data was recorded on-site--including the local windspeed. The result from these five houses were combined with the two Bay Area homes from the previous studies. The variability of the tests (represented by the standard deviation) is the repeatability of the test method for that house under the prevailing weather conditions. Because the testing was performed over a day a wide range of wind speeds was achieved following typical diurnal variations of low wind in the early morning and greatest winds in the late afternoon/early evening. Typically about ten tests were performed in each house. To answer the second question, different data analysis techniques were investigated that looked at averaging techniques, elimination of outliers, limiting leak pressures, etc. in order to minimize the influence of changing wind conditions during the test. The objective was to find a reasonable compromise between test precision and robustness--because many of the changes to the analysis to make the test more robust limit its ability to examine wide ranges of pressures and leakage flows. A secondary goal of this study is to show that DeltaQ uncertainties are acceptable for testing low leakage systems. Therefore houses with low duct leakage were deliberately chosen to be tested.
Download or read book Duct and Envelope Tightness written by ESCO PRESS and published by . This book was released on 2012-09-21 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book DW143 Guide to Good Practice written by Building and Engineering Services Association and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book India Rubber World and Electrical Trades Review written by and published by . This book was released on 1928 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:
