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A method for the determination of air infiltration rates in airplane cabins

Description: From Summary: "A method for the experimental determination of the rate of infiltration of air into aircraft cabins during flight has been developed and tested. This method consists of releasing a quantity of gas in the cabin and calculating the infiltration rate from the measured rate of change of the gas concentration. The results of the flight tests indicate that after the infiltration rate is established at one altitude and airspeed, the infiltration rates at other altitudes and airspeeds can be calculated."
Date: April 1946
Creator: Stalder, Jackson R. & Zeiller, E. Lewis
Partner: UNT Libraries Government Documents Department

Effectiveness of Urban Shelter-in-Place. II: ResidentialDistricts

Description: In the event of a short-term, large-scale toxic chemical release to the atmosphere, shelter-in-place (SIP) may be used as an emergency response to protect public health. We modeled hypothetical releases using realistic, empirical parameters to explore how key factors influence SIP effectiveness for single-family dwellings in a residential district. Four classes of factors were evaluated in this case-study: (a) time scales associated with release duration, SIP implementation delay, and SIP termination; (b) building air-exchange rates, including air infiltration and ventilation; (c) the degree of sorption of toxic chemicals to indoor surfaces; and (d) the shape of the dose-response relationship for acute adverse health effects. Houses with lower air leakage are more effective shelters, and thus variability in the air leakage of dwellings is associated with varying degrees of SIP protection in a community. Sorption on indoor surfaces improves SIP effectiveness by lowering the peak indoor concentrations and reducing the amount of contamination in the indoor air. Nonlinear dose-response relationships imply substantial reduction in adverse health effects from lowering the peak exposure concentration. However, if the scenario is unfavorable for sheltering (e.g. sheltering in leaky houses for protection against a nonsorbing chemical with a linear dose-response), the community must implement SIP without delay and exit from shelter when it first becomes safe to do so. Otherwise, the community can be subjected to even greater risk than if they did not take shelter indoors.
Date: December 1, 2006
Creator: Chan, W.R.; Nazaroff, W.W.; Price, P.N. & Gadgil, A.J.
Partner: UNT Libraries Government Documents Department

Development of convective testing methods for low-rise multifamily buildings. Final report

Description: This report describes convective testing methods and protocols developed for use in weatherizing low-rise multifamily buildings. The methods can lead to controlling internal air movement and preventing leakage to the exterior by estimating magnitudes of air leakage pathways in garden and town house apartments. The 4 methods cited are: After-a-Retrofit; Equivalent Interfaces; Open-a-Door; and Add-a-Pathway. It is found that, because of modern interior finishing practices, convective problems tend to be more associated with indoor air quality than loss of space conditioning energy. The After-a-Retrofit method is the easiest to integrate into current diagnostic practices. In some cases, the Equivalent Interfaces method may be used on a production basis. The methods are an advance on current field practices that do not quantify the leakage pathways and research practices that require extensive equipment.
Date: August 1, 1996
Creator: Stiles, M.R.
Partner: UNT Libraries Government Documents Department

The effect of air infiltration on the thermal performance of a small metal-framed assembly

Description: Innovative construction materials and systems have generated a need for laboratory scale tests to quantify the effect of air leakage on thermal and moisture performance of building assemblies. Some construction materials and systems are inherently more air tight than others. It is desirable to do laboratory scale measurements on alternative systems so as to rank them with respect to air tightness just as they can be ranked with respect to system R-value. Participants in summer 1995 and 1996 workshops for elementary and secondary school science teachers in the Buildings Technology Center (BTC) at the Oak Ridge National Laboratory sought a way to illustrate basic principles of building science in the classroom. They decided to build a small metal-framed assembly with internal volume of 44 ft{sup 3} (1.25 m{sup 3}) and removable wall sheathing. The assembly included a door and window. Although the door and window were made from 4-in. (10.2-cm) thick foam insulation, the requisite framing for them detracted from the thermal performance of the walls and occupied a disproportionately large fraction of the wall area. The floor and roof of the assembly were also well-insulated so that the walls dominated the conduction heat loss through the assembly. The plan was to test thermal performance of the assembly with the sheathing and without it. Thereby the teachers hoped to show the effects of thermal bridges with metal framing as well as practical yet insightful way to reduce their effects.
Date: March 1997
Creator: Petrie, T. W.; Christian, J. E. & Childs, P. W.
Partner: UNT Libraries Government Documents Department

SENSITIVITY OF THE HOUSE PRESSURE TEST FOR DUCT LEAKAGE TO VARIATIONS IN THE DISTRIBUTION OF AIR LEAKAGE IN THE HOUSE ENVELOPE

Description: The house pressure test for air leakage in ducts calculates the signed difference between the supply and return leakage from the response of the air pressure in the house to operation of the system fan. The currently accepted version of this calculation was based on particular assumptions about how the house envelope leakage is distributed between the walls, ceiling, and floor. This report generalizes the equation to account for an arbitrary distribution of envelope leakage. It concludes that the currently accepted equation is usually accurate to within {+-}5%, but in a small proportion of cases the results may diverge by 50% or more.
Date: December 1, 1998
Creator: ANDREWS,J.W.
Partner: UNT Libraries Government Documents Department

Emergency Protection from Aerosols

Description: Expedient methods were developed that could be used by an average person, using only materials readily available, to protect himself and his family from injury by toxic (e.g., radioactive) aerosols. The most effective means of protection was the use of a household vacuum cleaner to maintain a small positive pressure on a closed house during passage of the aerosol cloud. Protection factors of 800 and above were achieved.
Date: November 13, 2001
Creator: Cristy, G.A.
Partner: UNT Libraries Government Documents Department

Simplified multizone blower door techniques for multifamily buildings. Final report

Description: This research focused on the applicability of (a) two-blower-door and (b) single-blower-door multi-zone pressurization techniques for estimating the air leakage characteristics of New York State multi-family apartment buildings. The research also investigated the magnitude of external leakage area in multi-family buildings and used computer simulations to estimate the effect of decreasing external and internal leakage areas on air infiltration rates. This research investigates whether two blower doors can be used to determine the ELA of the exterior envelope and the ELA of partitions. Two multi-zone versions of the single-blower-door pressurization method are also examined.
Date: September 1, 1995
Partner: UNT Libraries Government Documents Department

GridLAB-D Technical Support Document: Residential End-Use Module Version 1.0

Description: 1.0 Introduction The residential module implements the following end uses and characteristics to simulate the power demand in a single family home: • Water heater • Lights • Dishwasher • Range • Microwave • Refrigerator • Internal gains (plug loads) • House (heating/cooling loads) The house model considers the following four major heat gains/losses that contribute to the building heating/cooling load: 1. Conduction through exterior walls, roof and fenestration (based on envelope UA) 2. Air infiltration (based on specified air change rate) 3. Solar radiation (based on CLTD model and using tmy data) 4. Internal gains from lighting, people, equipment and other end use objects. The Equivalent Thermal Parameter (ETP) approach is used to model the residential loads and energy consumption. The following sections describe the modeling assumptions for each of the above end uses and the details of power demand calculations in the residential module.
Date: July 31, 2008
Creator: Taylor, Zachary T.; Gowri, Krishnan & Katipamula, Srinivas
Partner: UNT Libraries Government Documents Department

Time-Averaged Indoor Radon Concentrations and Infiltration RatesSampled in Four U.S. Cities

Description: Indoor radon concentrations, measured in 58 houses over a four to five month period during the winter and spring of 1981-1982, varied from 0.1 to 16 pCi 1{sup -1} (4-590 Bq m{sup -3}). Average infiltration rates were determined for each house over the same period, based on a measurement of the effective leakage area and an infiltration model, and found to range from 0.2 to 2.2 air changes per hour (hr{sup -1}). Indoor radon concentrations correlated poorly with infiltration rates for houses within each city as well as for the entire sample. Differences in radon entry rates among houses thus appear to be more important than differences in infiltration rates in determining whether a house has high indoor radon levels, consistent with previous indications from grab-sample measurements. Radon entry rates and indoor radon concentrations were generally higher in houses in Fargo, ND and Colorado Springs, CO than in houses in Portland, ME and Charleston, NC.
Date: September 1, 1983
Creator: Doyle, S.M.; Nazaroff, W.W. & Nero, A.V.
Partner: UNT Libraries Government Documents Department

Will Duct Tape and Plastic Really Work? Issues Related to Expedient Shelter-In-Place

Description: Expedient sheltering involves the use of common materials to enhance the safety of a room inside a building against the impacts of a chemical plume. The central premise behind taping and sealing with duct tape and plastic is to reduce airflow into a room. This paper reviews issues associated with the use of expedient sheltering materials and the effectiveness of this strategy. Expedient sheltering provides additional protection to people sheltering in place beyond that provided by the house and by a safe room without expedient measures. The materials chosen for taping and sealing--duct tape and plastic--are appropriate because they effectively reduce infiltration and the materials should withstand a vapor challenge. Taping is essential to reduce air infiltration. Plastic sheeting is not a critical element for reducing air infiltration, but it makes sealing off large windows easier.
Date: August 30, 2002
Creator: Sorensen, J. H.
Partner: UNT Libraries Government Documents Department

Computational and Experimental Analysis of the Effectiveness of the Argon Reservoir

Description: Experimental and computational studies were performed to evaluate the effectiveness of an Argon Reservoir (AR). The AR is designed to prevent the ingress of air into the extraction furnace during the insertion and removal of the extraction basket, which contains Tritium Producing Burnable Absorber Rods. Computational computer code studies were performed to evaluate the AR design concept. Based on the results of this study it was concluded that the Argon reservoir would be very effective in keeping air and moisture from infiltrating into the furnace module if the reservoir was continuously supplied with make-up argon.
Date: February 11, 2003
Creator: Brizes, W.
Partner: UNT Libraries Government Documents Department

Encasing lead hazards and adding energy efficiency in low-income housing

Description: Field research has confirmed that the lower the incremental (marginal) cost of producing an outcome, the more likely that production will occur. In residential building rehabilitation the economic truth suggests that energy efficiency is likely to become part of the scope of work of a project when the additional cost of conservation measures are relatively small, i.e., comparing gut rehab to moderate rehab, replacement of a furnace with an energy efficient model, and low-cost solutions to address lead poisoning hazards. Energy efficiency must fit into the overall needs and opportunities of a building retrofit. If little is being done to the building, then few measures can be expected to be justified. If much must be done, however, the opportunities for conservation are likely to be great. An example of this is the composite wall system described, therein, that was developed to address the problem of lead poisoning hazards on wall surfaces while adding a tight, well-insulated, and strong interior surface to perimeter walls at the lowest possible cost.
Date: March 1, 1997
Creator: Cavallo, J.D. & Wendt, R.
Partner: UNT Libraries Government Documents Department

The performance check between whole building thermal performance criteria and exterior wall measured clear wall R-value, thermal bridging, thermal mass, and airtightness

Description: At the last IEA Annex 32 meeting it was proposed that the annex develop the links between level 1 (the whole building performance) and level 2 (the envelope system). This paper provides a case study of just that type of connection. An exterior wall mockup is hot box tested and modeled in the laboratory. Measurements of the steady state and dynamic behavior of this mockup are used as the basis to define the thermal bridging, thermal mass benefit and air tightness of the whole wall system. These level two performance characteristics are related to the whole building performance. They can be analyzed by a finite difference modeling of the wall assembly. An equivalent wall theory is used to convert three dimensional heat flow to one dimensional terms that capture thermal mass effects, which in turn are used in a common whole building simulation model. This paper illustrates a performance check between the thermal performance of a Massive ICF (Insulating Concrete Form) wall system mocked up (level 2) and Whole Building Performance criteria (level 1) such as total space heating and cooling loads (thermal comfort).
Date: June 1, 1998
Creator: Kosny, J.; Christian, J.E.; Desjarlais, A.O.; Kossecka, E. & Berrenberg, L.
Partner: UNT Libraries Government Documents Department

ERROR REDUCTION IN DUCT LEAKAGE TESTING THROUGH DATA CROSS-CHECKS

Description: One way to reduce uncertainty in scientific measurement is to devise a protocol in which more quantities are measured than are absolutely required, so that the result is over constrained. This report develops a method for so combining data from two different tests for air leakage in residential duct systems. An algorithm, which depends on the uncertainty estimates for the measured quantities, optimizes the use of the excess data. In many cases it can significantly reduce the error bar on at least one of the two measured duct leakage rates (supply or return), and it provides a rational method of reconciling any conflicting results from the two leakage tests.
Date: December 31, 1998
Creator: ANDREWS, J.W.
Partner: UNT Libraries Government Documents Department

Loose-fill insulations

Description: Whether you are increasing the insulation levels in your current home or selecting insulation for a new home, choosing the right insulation material can be challenging. Fibrous loose-fill insulations such as cellulose, fiberglass, and rock wool are options you may wish to consider. This publication will introduce you to these materials--what they are, how they are applied, how they compare with each other, and other considerations regarding their use--so that you can decide whether loose fills are right for your home.
Date: May 1, 1995
Partner: UNT Libraries Government Documents Department

Heat Recovery in Building Envelopes

Description: Infiltration has traditionally been assumed to contribute to the energy load of a building by an amount equal to the product of the infiltration flow rate and the enthalpy difference between inside and outside. Application of such a simple formula may produce an unreasonably high contribution because of heat recovery within the building envelope. Previous laboratory and simulation research has indicated that such heat transfer between the infiltrating air and walls may be substantial. In this study, Computational Fluid Dynamics was used to simulate sensible heat transfer in typical envelope constructions. The results show that the traditional method may over-predict the infiltration energy load by up to 95 percent at low leakage rates. A simplified physical model has been developed and used to predict the infiltration heat recovery based on the Peclet number of the flow and the fraction of the building envelope active in infiltration heat recovery.
Date: January 1, 2001
Creator: Sherman, Max H. & Walker, Iain S.
Partner: UNT Libraries Government Documents Department

Leak-Path Factor Analysis for the Nuclear Materials Storage Facility

Description: Leak-path factors (LPFs) were calculated for the Nuclear Materials Storage Facility (NMSF) located in the Plutonium Facility, Building 41 at the Los Alamos National Laboratory Technical Area 55. In the unlikely event of an accidental fire powerful enough to fail a container holding actinides, the subsequent release of oxides, modeled as PuO{sub 2} aerosols, from the facility and into the surrounding environment was predicted. A 1-h nondestructive assay (NDA) laboratory fire accident was simulated with the MELCOR severe accident analysis code. Fire-driven air movement along with wind-driven air infiltration transported a portion of these actinides from the building. This fraction is referred to as the leak-path factor. The potential effect of smoke aerosol on the transport of the actinides was investigated to verify the validity of neglecting the smoke as conservative. The input model for the NMSF consisted of a system of control volumes, flow pathways, and surfaces sufficient to model the thermal-hydraulic conditions within the facility and the aerosol transport data necessary to simulate the transport of PuO{sub 2} particles. The thermal-hydraulic, heat-transfer, and aerosol-transport models are solved simultaneously with data being exchanged between models. A MELCOR input model was designed such that it would reproduce the salient features of the fire per the corresponding CFAST calculation. Air infiltration into and out of the facility would be affected strongly by wind-driven differential pressures across the building. Therefore, differential pressures were applied to each side of the building according to guidance found in the ASHRAE handbook using a standard-velocity head equation with a leading multiplier to account for the orientation of the wind with the building. The model for the transport of aerosols considered all applicable transport processes, but the deposition within the building clearly was dominated by gravitational settling.
Date: June 13, 1999
Creator: Shaffer, C. & Leonard, M.
Partner: UNT Libraries Government Documents Department

Measured winter performance of storm windows

Description: Direct comparison measurements were made between various prime/storm window combinations and a well-weatherstripped, single-hung replacement window with a low-E selective glazing. Measurements were made using an accurate outdoor calorimetric facility with the windows facing north. The doublehung prime window was made intentionally leaky. Nevertheless, heat flows due to air infiltration were found to be small, and performance of the prime/storm combinations was approximately what would be expected from calculations that neglect air infiltration. Prime/low-E storm window combinations performed very similarly to the replacement window. Interestingly, solar heat gain was not negligible, even in north-facing orientation.
Date: August 23, 2002
Creator: Klems, Joseph H.
Partner: UNT Libraries Government Documents Department

Air tightness of new houses in the U.S.: A preliminary report

Description: Most dwellings in the United States are ventilated primarily through leaks in the building shell (i.e., infiltration) rather than by whole-house mechanical ventilation systems. Consequently, quantification of envelope air-tightness is critical to determining how much energy is being lost through infiltration and how much infiltration is contributing toward ventilation requirements. Envelope air tightness and air leakage can be determined from fan pressurization measurements with a blower door. Tens of thousands of unique fan pressurization measurements have been made of U.S. dwellings over the past decades. LBNL has collected the available data on residential infiltration into its Residential Diagnostics Database, with support from the U.S. Department of Energy. This report documents the envelope air leakage section of the LBNL database, with particular emphasis on new construction. The work reported here is an update of similar efforts carried out a decade ago, which used available data largely focused on the housing stock, rather than on new construction. The current effort emphasizes shell tightness measurements made on houses soon after they are built. These newer data come from over two dozen datasets, including over 73,000 measurements spread throughout a majority of the U.S. Roughly one-third of the measurements are for houses identified as energy-efficient through participation in a government or utility program. As a result, the characteristics reported here provide a quantitative estimate of the impact that energy-efficiency programs have on envelope tightness in the US, as well as on trends in construction.
Date: March 1, 2002
Creator: Sherman, Max H. & Matson, Nance E.
Partner: UNT Libraries Government Documents Department

Zone conditioning in a California foothill house

Description: The principal focus of the reported research is the performance of the installed zoned air distribution system in a house located in the foothills northeast of Sacramento California. The 297 m{sup 2} two story house contained a central air conditioner and an air distribution system with four dampered supply duct legs. The air conditioning system included a two speed fan and two speed compressor, with the air handler placed inside a closet and almost all the ducts located inside the building envelope. The uninsulated sheet metal ducts ran inside a space between stories and in interior walls. The performance parameters examined included: (1) duct leakage, (2) duct conduction, (3) zoning performance and (4) equipment efficiency impacts. In conclusion, two major points were made concerning the test house. The first was that substantial energy benefits were obtained by placing the ducts inside the conditioned space. The second was that the energy benefits from zoning the house were not realized, primarily due to thermal stratification and the open floor plan in the house. Secondary impacts lowering zoning performance were the k& of return duct dampers and leakage and conduction losses in the air distribution system. Utility programs or building standards promoting zoning as a means of conserving energy or reducing peak power demand should be aware of the many potential pitfalls that can arise with zone conditioning, particularly with dampered air distribution systems.
Date: December 1, 1993
Creator: Jump, D. & Modera, M.
Partner: UNT Libraries Government Documents Department

Assessment of Indoor Air Quality Benefits and Energy Costs of Mechanical Ventilation

Description: Intake of chemical air pollutants in residences represents an important and substantial health hazard. Sealing homes to reduce air infiltration can save space conditioning energy, but can also increase indoor pollutant concentrations. Mechanical ventilation ensures a minimum amount of outdoor airflow that helps reduce concentrations of indoor emitted pollutants while requiring some energy for fan(s) and thermal conditioning of the added airflow. This work demonstrates a physics based, data driven modeling framework for comparing the costs and benefits of whole-house mechanical ventilation and applied the framework to new California homes. The results indicate that, on a population basis, the health benefits from reduced exposure to indoor pollutants in New California homes are worth the energy costs of adding mechanical ventilation as specified by ASHRAE Standard 62.2.This study determines the health burden for a subset of pollutants in indoor air and the costs and benefits of ASHRAE's mechanical ventilation standard (62.2) for new California homes. Results indicate that, on a population basis, the health benefits of new home mechanical ventilation justify the energy costs.
Date: July 1, 2011
Creator: Logue, J.M.; Price, P.N.; Sherman, M.H. & Singer, B.C.
Partner: UNT Libraries Government Documents Department