Blower Door Test Research Articles

Penetration of ambient submicron particles into single-family residences and associations with building characteristics

This work improves knowledge of particle penetration into buildings by (i) refining a particle penetration test method that minimizes the duration and invasiveness required by individual tests without sacrificing accuracy, (ii) applying the method in an unoccupied manufactured test house and 18 single-family homes in Austin, Texas, USA, and (iii) exploring correlations between particle penetration and building characteristics, including results from blower door air leakage tests. The mean (± s.d.) measured penetration factor of submicron particles (20-1000 nm, not size-resolved) was 0.47 ± 0.15 in 19 residences that relied on infiltration for ventilation air, ranging from 0.17 ± 0.03 to 0.72 ± 0.08. Particle penetration factors (P) and outdoor particle source terms (P × air exchange rates) were both significantly and positively correlated with results from blower door air leakage tests. Outdoor particle source terms were also significantly and negatively correlated with the year of construction. These results suggest that occupants of leakier and older homes are exposed to higher indoor concentrations of outdoor submicron particles than those in tighter and newer homes, and that simple air leakage tests may be able to provide an approximate prediction of outdoor particle infiltration into single-family residences. Results from this work suggest that knowledge of simple building characteristics (i.e., the year of construction and blower door test results) may be used to predict the ability of outdoor particles to infiltrate into single-family residences, which could facilitate easier estimates of indoor exposures to outdoor particulate matter across the building stock. The methods within can also be extended to other buildings and can be used to assess possible changes in penetration factors because of envelope retrofits. Because outdoor particle size distributions were not measured during this study, these tests should also be repeated with size-resolved particle instrumentation.

Experimental analysis of air tightness in Mediterranean buildings using the fan pressurization method

Building air tightness plays an important role both on the energy saving and the indoor thermal comfort. Several studies in recent years have been carried out in US and in northern Europe, usually under cold climatic conditions, whereas Mediterranean buildings are not deeply investigated in literature.In this paper the authors present the results of an experimental study carried out on residential buildings located in southern Italy using the fan pressurization method, also known as “blower door test” (BDT). In particular, the main metrological aspects in air tightness measurement of buildings and the influence of air leakage on energy consumption and indoor comfort in different architectural typologies typical of the Mediterranean area are focused.The experimental results presented can give some interesting suggestions to improve the measurement uncertainty in BDT and to better detect energy and environmental criticalities in the building audits.

EVER GREEN: A POST-OCCUPANCY BUILDING PERFORMANCE ANALYSIS OF LEED CERTIFIED HOMES IN NEW ENGLAND

The purpose of this research was to conduct a pilot study of LEED certified homes in New England one to five years after occupancy to determine whether they continue to perform at the level predicted during the certification process. Four criteria were defined to assess the performance of each home: (1) energy consumption for heating, cooling, lighting, electronics and appliances; (2) building envelope and air infiltration; (3) operations and maintenance; and (4) occupant satisfaction and indoor air quality. Both qualitative and quantitative methods including blower door and duct blaster tests, utility bill analysis, and an occupant satisfaction survey were used to measure the post-occupancy performance of seven LEED certified homes in New England. Discrepancies were found between the original building performance as determined at the time of certification and the current level of building performance. While this is limited, initial research, these findings indicate a need for further post-occupancy research that can provide feedback to green certification programs, allowing them to be modified as necessary to better reflect the actual environmental impacts of certified buildings.

Low-Energy House in Arctic Climate: Five Years of Experience

AbstractThe aim of this article is to present and discuss the experience gained from a low-energy house in Sisimiut, Greenland, over the 5 years of operation since its inauguration in April 2005. The house was designed to test and present new low-energy technologies in the Arctic climate and to improve sustainability in Greenlandic buildings. The article presents some measurements, analyses, and comparisons of theoretical simulations and some steps that were taken to improve the house with impacts on energy consumption. The results include energy consumption, temperatures, and solar heating production. Also presented are the results of several investigations carried out in the house, such as blower-door tests and inspection of the ventilation system. The initial target for the heating demand of the house was that it should be restricted to 80 kWh/(m2·a), but in reality it has varied over the past 5 years from 139 to 150 kWh/(m2·a). Currently the house is on the way to presenting a good energy solution, ...

A study to optimize the potential impact of residential building energy audits

The Colorado College Energy Audit and Retrofit Program is a non-profit organization that teaches students the science and mechanics involved in energy audits and retrofit work through service–learning and community-based research projects. This approach represents a “win–win” scenario where the college contributes to maximize learning and minimize costs to the community. The method of identifying homes for energy audits has evolved from responding to homeowner requests to a proactive approach aimed at targeting older low-income neighborhoods and working with existing neighborhood associations. Recent work on the Mill Street Neighborhood in Colorado Springs, Colorado is presented in which a sample of homes (N = 14) received thermal audits, complete with blower door tests and Energy-10 computer modeling. The results are tabulated, analyzed, and extrapolated over the entire 145 homes in the neighborhood. The normally distributed ACH n values and the skewed distributions of R aver values and building sizes are discussed. A method of identifying unusual occupant behavior, relative to the building quality, is presented where the Home Heating Index is compared to a Building Thermal Performance Index (R aver/ACH n ). Estimates from extrapolation of the data predict that an investment of $146,500 USD in retrofit materials will yield a total annual neighborhood savings in energy, utility costs and GHG emissions of 9.1 × 106 kBtu (9.6 × 109 kJ), $64,000 USD and 555 US tons (5.0 × 105 kg), respectively, providing a simple payback time of 2.3 years. This efficient method of neighborhood energy audits provides data that could support neighborhood renewal grant proposals to purchase materials for follow-up retrofits and supports municipal demand-side management programs.

Case studies of building envelope leakage measurement using an air-handler fan pressurisation approach

The air-handler fan pressurisation method can be a practical way to estimate envelope leakage in large scale or tall buildings where a conventional blower door test is not practical. Standards such as CGSB 149.15 describe desirable test conditions and protocols for such tests. However, because of the variety of building air handling system constructions and site conditions, and limited time and budget available for testing, one may not be able to perform the test under the recommended standard conditions, especially when the system configuration and operation at the site are unfavourable. This study describes air-handler fan pressurisation tests performed for two existing buildings having problematic site conditions affected the ability to perform standard test protocols. Envelope leakage was measured with and without sealing of elevator shafts. Both buildings were found to have standard leakage flow rates that exceed typical levels, with or without elevator shaft leakage. This paper provides some insight into what should be done to ensure a successful air-handler fan pressurisation test by describing what was done to deal with undesirable site conditions which could occur in many buildings. Practical applications: This study shows that air-handler fan pressurisation tests can be performed even in problematic buildings by improving test conditions at the site by adjusting the system operation and by utilising site specific measurement techniques and instrumentation. The applicability of recently developed fan airflow and outdoor intake flow measuring sensors to the air-handler fan pressurisation test is also discussed. However, it also shows that perfect implementation of standard air-handler fan pressurisation test procedure may be difficult in real buildings for a reasonable cost. Published case studies providing methods for solving various practical problems at the test site are very rare. This paper is useful for engineers who are seeking practical information about the air-handler fan pressurisation.

Air tightness measurements of residential houses in Athens, Greece

During summer 2005, regular air tightness and infiltration measurements were performed in 20 houses, in the area of Attica, Greece. Two measurement methods were used, the tracer gas decay method and the Blower Door tests method. Blower Door measurements were done in accordance with EN ISO 13829 [Hellenic Standard “Thermal performance of buildings—determination of air permeability of buildings—fan pressurization method”]. Ambient conditions and temperature fluctuations inside the houses were measured as well. The average number of air changes per hour (ACH) was approximately 0.6 ACH, when tracer gas method was used, while the average number of ACH at a 50 Pa pressure was 7 ACH, when the Blower Door tests method was used. A classification of houses examined, based on experiments’ results was acted out in accordance with EN ISO 13790 [former 832. “Thermal performance of buildings—calculation of energy use for heating”]. The houses were classified into three air tightness categories, in regard to their air tightness in natural conditions and at a pressure difference of 50 Pa. A statistical homogeneity test between regression coefficients of Blower Door measurements is performed for each category of air tightness. The sample of buildings that belong to the “low air tightness level” category are statistically homogeneous, while the samples of buildings that belong to the “medium” and “high” air tightness level are statistically uneven. Finally, the total frame length was estimated for the whole housing stock, and a correlation between the air tightness measurements at a pressure difference of 50 Pa and the total frame length was examined, for the sample of buildings and for each air tightness category. The correlation coefficient R 2 has the greater values at the “low air tightness” category.

Impact of Heating and Air Conditioning System Operation and Leakage on Ventilation and Intercompartment Transport: Studies in Unoccupied and Occupied Tennessee Valley Homes

Forced-air heating and air conditioning (HAC) systems caused an average and maximum increase in air infiltration rates of 1.8- and 4.3-fold, respectively, during brief whole-house studies of tracer gas decay in 39 occupied houses. An average increase in air infiltration rate of 0.33 +/- 0.37 h-1 corresponded to an incremental air leak of 240 m3/h, based on approximate house volume. More detailed tracer gas decay studies were performed in basement, kitchen and bedroom locations of six homes with low air infiltration rates (i.e., less than 0.25 h-1). The HAC mixed the indoor air efficiently between measurement sites. HAC operation also caused 1.1- to 3.6-fold increases in air infiltration rates, corresponding to absolute increases of 0.02 to 0.1 h-1. In an unoccupied research house, three-fold increases in average air infiltration rate with HAC operation (i.e., from 0.13 to 0.36 h-1) were reduced to two-fold (i.e., from 0.10 to 0.18 h-1) by sealing the external HAC unit and crawlspace ductwork system. This sealing also resulted in a 30 percent reduction in crawlspace-to-indoor transport rates with the HAC turned on. Blower door tests indicated a less than 20 percent reduction in house leakage area.