Residential ventilation accounts for 1/3 to 1/2 of the energy load of dwellings and is a key factor in determining indoor air quality. Residential ventilation has been an active area at Lawrence Berkeley National Laboratory since the late 1970s.
The Energy Performance of Buildings Group has been DOE's major research center on this topic since the late 70s. This home page is intended to be a source of information on residential ventilation. It contains a BIBLIOGRAPHY, a KEY PERSONNEL list, and an ON-LINE ANALYSIS program for estimating the annual ventilation and related energy liabilities for U.S. houses. (To use some of these features requires the users to log in).
The general topic of residential ventilation is broken up into several research areas:
If after reviewing the information on this and related pages, you have specific questions, we would be happy to answer your technical inquiry.
A general description of Blower Doors and the use of data including the LBL Model is in the paper entitled "The Use of Blower Door Data".
For more, general information you can link to
If you have any technical inquires regarding residential ventilation please send e-mail to the Energy Performance of Buildings Group
MODELING AND SIMULATION
The LBL Infiltration Model was first developed in the late 1970s and incorporated into the ASHRAE Handbook of fundamentals. It is a simplified physical model that treats a building as a single zone. It is the core of most of the single-family building ventilation modeling.
The COMIS Model has been developed over the last few years and is a high-powered, multizone air flow modeling program suitable for determining mass and pollutant transport of very complex building environments.
INSTRUMENTATION AND MEASUREMENT
Getting the detailed characteristics of existing buildings requires measurement. Since the late `70s LBL has developed many new measurement techniques and protocols as well as developing formalisms for describing building data in useful ways. The concept of the Effective Leakage Area is useful for quantifing building air tightness and can be measured with Blower Doors or other forms of fan pressurization.
Measurement of air exchange is fundamental to ventilation, both for direct determination and for model validation. LBL has been instrumental in developing equipment for measuring air change rates using Tracer Gasses. LBL's full fuatured version is called the MultiTracer Measurement System (MTMS) and uses Gas Chromatography to measure concentrations of different tracer gases in several zones and then analyze the data to determine air flows.
LBL has worked extensively with ASTM in developing measurement techniques for air leakage, air change rate measurement, and other standards related to building constructions.
CHARACTERIZATION AND ANALYSIS
In recent years efforts have focussed on using the data gathered on building air tightness and combining it with other data (Census, weather and RECS data) to understand the stock of U.S. houses. We collectively refer to the combined package of databases and models as ResVent.
We have used ResVent (single zone hourly simulation program based on LBL infiltration model) to estimate the distribution of residential ventilation rates, the associated energy impacts and cost-effective retrofits for the stock. We have also used it to examine ventilation options for new construction.
Recent analyses have shown an enormous energy savings potential through envelope tightening retrofits. Cost effective potential approaches 2 Quads at saturation.
Energy savings and optimal strategies are climate dependent. Research in this area would be to define retrofit protocols and the determination of optimal levels of tightness, and/or incorporation of mechanical systems. Implementation activities would include program design and piloting as well as rating.
Because new houses already have significantly improved air tightness, potential efficiency improvements in new construction are more modest. Recent studies indicate, however, that many new houses may be underventilated, even though cost-effective ventilation strategies exists. Research in this area would help to define appropriately designed ventilation/envelope systems for cost-effectively providing adequate ventilation. Implementation activities would include code changes and demonstration houses.
There is a clear impact on Home Energy Rating Systems (for both new and existing). There is a need to improve the rating to adequately incorporate and trade-off infiltration and mechanical ventilation.
LBL continues to be DOE's lead Lab on residential ventilation,
has completed numerous analyses on residential ventilation from national perspective,
represents U.S. to IEA Annex 5, Air Infiltration and Ventilation Centre,
has extensive experience with heat exchange systems,
has developed and used all major measurement systems appropriate for residential ventilation measurements (e.g. blower door, tracer gas, airflow hoods, etc.),
is actively pursuing these topics for DOE (on an ever decreasing budget),
leads U.S. in airflow simulation capabilities,
participates on air tightness and ventilation standards activities with ASHRAE (as well as test methods with ASTM).
STATE AND REGIONAL IMPACTS
Different regions have different needs because of both climate and housing stock differences. National analyses may not adequately include state-specific issues.
MILD CLIMATE States
can make good use of infiltration and natural ventilation. Also passive ventilation as used in Europe may be quite cost effective, but needs to be developed for U.S. situations.
HOT HUMID States
have the concern about humidity control and need more detailed look at heat/enthalpy exchangers for summer use.
have different humidity control issues and need to evaluate trade-off between heat-recovery and non-recovery mechanical ventilation systems.
The core of the ResVent model has been put on line and can be used to estimate ventilation liabilities for particular single-family buildings. The model provides default values based on our stock characterization, but allows the user to enter specific inputs for a building of interest.
* BIBLIOGRAPHY, * a EPB PERSONNEL list,* The TOP of this page *