A unique capability to measure part-per-quadrillion concentrations of a family of perfluorocarbon tracers (PFTs) is presented. Together with our unique PFT source and passive sampler, measurement of average air exchange and infiltration rate can be determined for periods as short as 12 hours. A more expensive programmable sampler can provide information on a frequency of as little as once per minute for each of its 23 sampling tubes. The principal of AIMS is based on the applicable steady-state assumption that the average concentration (e.g., in pL/L) of a tracer vapor in a chamber (i.e., a building or room) is equal to the emission rate of the tracer source (e.g., in pL/min) divided by the air leakage or infiltration rate (e.g., in L/min). Knowing the source rate and measuring the average concentration then provides a means to calculate the air leakage rate. Extending this technique to a multichamber concept, in which a different type of PFT source is deployed in each chamber of a building, allows the calculation of not only the infiltration rates in each chamber but also the air exchange rates between chambers as well. Since both the PFT source and the passive sampler, a miniature Capillary Adsorption Tube Sampler (CATS), are about the size of a cigarette, inexpensive, and reusable, the BNL/AIMS is a very cost-effective means (if not the only means) for determining these air exchange rates

Cote, E.A.

Dietz, R.N.

Goodrich, R.W.

Wieser, R.F.

Dietz, R. N.

Goodrich, R. W.

Cote, E. A.

Wieser, R. F.

UNT Digital Library

« i i i i i i ill! iiiiiiiiiin ! I ! • m ihiiHiiiJ iiilHl! ' in nil! I hiHi i i ! MlHl l i M l i j i j i i i ff\ \ ({ inniiinnii!!: Hi liili yi j j .HH Hiini iiili!!!!!!! Mini i i i H Ml ISilil IMilliililliij!! 'iii h i ? I ^ i i!H! illi! I I i ' ) M M M i ( ! ' ^ i n m l iiiililliii !i i l i iniiiHi ,.;.!|inl!;|!niih|H;i ng Mil Hi niNi^H'liHiiii hnn I ! M 11111 'Hiij iiiil! Hi iinlilliililllliiiiilll MfS i i i i i n i i i h s n - ' .̂JiiHiiliii ^^s îHi Hi I Ml ! i ; III! ililiî i'î  IMl il lilliiiH m lliiiiiiiiiiil l i l j i i iiliiH! h i H i i l i i iJiil! i l i! i i i l l l ilii!! iinii ! Iiiiii iilH Hi! hn in ilM I! in Hi! ! j l ; ! i n - ' ' iilii ii ii ! i n n HI Ml H hi! i l ! 1 I I I ! h H i n nn i iMii 11!! iillli !l! \m I ii pi i i I l!ii II ii ii MM ill iliiiiliiiiiii I illililliilMiliii ill ! BROOKHAVEN AIR INFILTRATION MEASUREMENT SYSTEM (BNT./AIMS) DESCRIPTION AND APPLICATION Russell N. Dietz, Robert W. Goodrich, Edgar A. Cote, and Robert F. Wieser AUGUST 1 9 8 3 ,1%J % -S,i •^'^ "V' 8 H C I a""4 I , DlSTfiiBOTiON Of TliiS POCOMENT iS OKuMtTFD OtPARTiENT OF APPUtO SCfEMCt A T i O N A L LABO ^PTON, LONG SSLAND, NEW RATORY •HK 11973 |liill|i!i|iiilllii!|!i! iipiii!iiii!ii|ii!||iiii|^ liii i iipppi HTN m^ \ î! i l I i l i il i i i ii iiî  i n n ; liiiiiiiiliiiiiiiiiiiiiiiiiijiililiiiiiiiii inn liii liipliili liljpli i U M I M l i i H i ; i l l n llliliiiiiilli DISCLAIMER  This report was prepared as an account of work sponsored by an agency of the United States Government.  Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights.  Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.  The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. DISCLAIMER  Portions of this document may be illegible in electronic image products.  Images are produced from the best available original document.  BNL—33846 DE85 014884 BROOKHAVEN AIR INFILTRATION MEASUREMENT SYSTEM (BNL/AIMS) DESCRIPTION AND APPLICATION Russell N. Dietz, Robert W. Goodrich, Edgar A. Cote, and Robert F. Wieser AUGUST 1983 3:iL.~3 304c DE04 025455 Prepared for the Office of Building and Community Systems and the Office of Health and Environmental Research of the United S t a t e s Department of Energy iSTICE pOBTtins OF mm HEPSIT ABE i i i t i ieit . it has beei reprciaced from the test awallaMe copf to permit the broadest possible availability. ENVIRONMENTAL CHEMISTRY DIVISION DEPARTMENT OF APPLIED SCIENCE BROOKHAVEN NATIONAL LABORATORY ASSOCIATED UNIVERSITIES, INC. Under Contract No. DE-AC02-76CH00016 with the U.S. Department of Energy iSIRiUIIOfi §F l i s OOCUiENT IS WLIMITa DISCLAIMER This report was prepared as an account of work, sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, nor any of their contractors, subcon-tr'ac'tiors, or their employees, makes any warranty, expressed or implied, or* assumes any legal liability or respon-sibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately ownfed rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency or subcontract thereof* Introduction An important aspect of any study on Indoor air quality or building energy performance is the need to know the rates at which air is mixed or exchanged between zones within the building structure as well as the rates of infiltration of fresh air and exfiltration of stale air for each zone. » Combining this information with the locations and rates at which pollutants are both generated and scavenged, would then provide the complete detail necessary for modeling and predicting the air quality throughout a building. Brookhaven has developed a unique capability to measure part-per-quadrillion concentrations of a family of perfluorocarbon tracers (PFTs). Together with our unique PFT source and passive sampler, measurement of average air exchange and infiltration rate can be determined for periods as short as 12 hours. A more expensive programmable sampler can provide Infor-mation on a frequency of as little as once per minute for each of its 23 s amp1ing tub e s• The principal of AIMS is based on the applicable steady-state assump-tion that the average concentration (e.g., in pL/L) of a tracer vapor in a chamber (i.e., a building or room) is equal to the emission rate of the tracer source (e.g., in pL/min) divided by the air leakage or infiltration rate (e.g., in L/mln). Knowing the source rate and measuring the average concentration then provides a means to calculate the air leakage rate. Extending this technique to a multichamber concept. In which a different type of PFT source is deployed in each chamber of a building, allows the calculation of not only the infiltration rates in each chamber but also the air exchange rates between chambers as well. Since both the PFT source and the passive sampler, a miniature Capillary Adsorption Tube Sampler (CATS), are about the size of a cigarette, inexpensive, and reusable, the BNL/AIMS is a very cost-effective means (if not the only means) for determining these air exchange rates. Use of BNL/AIMS in Homes Figure 1 shows a capillary adsorption tube sampler (CATS) on the left and a PFT source on the right. The attractiveness of this system is that both the source and the sampler are inexpensive, passive, and easily mailed to the user. A second version of a CATS device (model PS-4) is shown in Figure 2 and is even simpler to manufacture. During deployment of the sys-tem in a home, a PFT source is placed in each major room of a house, gener-, ally one for each 500 ft^ of living space. This establishes a uniform tracer concentration within the house. From 2 to 4 passive samplers (CATS) are located throughout the house. Sampling commences by passive Flckian diffusion to the adsorbent in the middle of the glass tube when one cap is removed. At the end of the designated sampling period, the cap is replaced and the sampler is mailed back to the laboratory where it is thermally desorbed on a special multiple CATS rack (see Fig. 3) for determination on a gas chromatograph system. The concentration is calculated knowing the sample duration and the air leakage rate is calculated knowing the number of ; I.^^SvX^ •f 1 1 m • • CM • -_ m X s Figure 1, Passive sampler (FS-1) and PFT source Figure 2. Passive sampler CPS-4) CAM CAM ARM REMOVABLE END 0-RING /SEAL HEATER 0-RING SEAL PISTON SPRING THERMAL DESORPTION APPARATUS Figure 3 . PFT sources deployed. Complete details of the techique are provided in three publications. •'•'̂'-̂  The only precaution that must be observed with this technique is that the sources and samplers must be shipped and stored separately to avoid contamination of the samplers with PFTs. Thus, control or unused samplers are routinely considered to ascertain sample integrity. Validation of AIMS with LBL SF^ Technique. For the period from June 10 to June 30, 1982, the BNL/AIMS system was deployed in the Lawrence Berkeley Laboratory (LBL) test house in Chicago. This house was equipped with an automated SFQ tracer decay system whicn measured the infiltration rate every 90 ain. During this period 2 PFT sources were deployed, one in the basement and one on the main floor, as well as two passive samplers each in the basement and main floor. Table 1 shows the results of the analysis of the four passive samplers. The first and fourth tubes were on the main floor. CATS no. 258 was in the living room where the source was located and no. 250 was at the other end of the house in a bedroom. This accounts for the lower measured concentration in the bedroom which had no source. The second and third CATS tubes were located in the basement, which was a more open space. The two samplers were also about equi-distant from the source, accounting for the more uniform measured concentration. Using the average concentration from the four samplers, i.e., 10.8 pL/L, an average air exchange rate of 0.31 * 0.04 ACH (air changes per hour) was determined. LBL determined a mean value of 0.33 ACH from a total of 306 SF5 decay measurements, in excellent agreement with the BNL/AIMS result. Example of Single Zone Measurements. In a collaborative study with a Canadian firm, bi-weekly measurements were made in 7 homes in Canada for two test periods. A typical result is shown in Table 2 for house no. 28. Four sources and samplers were deployed in the two-story house with a basement, one of each in the dining and family rooms (1st floor) and the master bedroom and single bedroom (2nd floor), listed, respectively, as CATS numbers 642, 639, 653, and 658. The average infiltration rate was 0.10 ± 0.01 ACH, when the basement volume was included and 0.15 ACH without the basement volume, which is the preferred mode of calculation. A summary of the results in the 7 homes for the two test periods is shown in Table 3. The trend towards a slightly lower infiltration rate in the second period compared to the first was remarkably consistent, indicative of a warmer period in the second 2 weeks. Example of a Multi-Zone Measurement. An example of the type of 3-zone results obtained recently in the Brookhaven passive solar heated house is shown in Table 4. Given for each of the 3 zones in the house (1 IS the second floor, 2 is the first floor, and 3 is the basement) is the volume, the PFT type and emission rate, the average concentration of each PFT type. TABLE 1 CATS ANALYSIS TUBI POS CHTS NO. HRS, SHMP, INTEGPATOP AREA, CTS/1000 PMCH PDCH PFT MOL*fPL PflCH PDCH PFT CONC. pL/L PMCH PDCH i V 3 4 HOUSE LBl 250 262 2 5 D 258 476.£1 4?6.0 476,0 4?6,y HO. SOURCES 2 U34S.0 14357.0 14646.8 15582.0 T(ceTit) 22 32.463 41.092 41.917 44.584-LAST TUBE POS, 4 8.744 11.063 11.290 12.008 OUSE NO. HOUSE UOLUME 1 iters SOURCE RATE TiL'Tlin AUG. CONCENT pL/L INFILT. RATE L/f'iiTi AUG.AIR CHANGE per hr REL.STD DEU. '4 LBl 481333 27.2 10,8 2526 0.31 13.1 TABLE 2 BNL-AIMS ANALYSIS ACCOUNTS PAR TRACERS PDCH DATES SAMPLED a22883«031583 HOUSE MOLUME 739' SOURCE RATE uL/nit^ 66,0 AUG, CONCENT pL/L 58.5 CATS HO. 642 639 653 658 FILES 1? HOUSES PR2S DATE AHAL.S 3/29/83 IHFILT. AUG.AIR REL.STD. RATE' CHANGE DEM. ?8 TRACER COHC, 5hl 44.6 48.1 58.6 per hr 0.10 11.8 Table 3 Summary of Single Zone Infiltration Results Avg. Air Changes per Hour (Rel. Std. Dev.) 2/15 - 2/28783" 2/28 - 3/15/83 0.23 (* 33%) 0.21 (± 41%) 0.19 (± 18%) 0.17 (± 17%) 0.41 (± 4%) 0.40 (± 8%) 0.17 (± 15%) 0.15 (± 12%) 0.29 (± 30%) 0.24 (ir 28%) 0.20 (± 17%) 0.18 (± 22%) 0.29 (± 20%) 0.27 (:t 25%) TABLE ^ BHL-AIHS ACCOUNTS BNL 3/83 HOUSESBHL5 DATES SHMPLEDS 032983-048283 #20HESS3 FILES 48 DATE AHALS 5 / 2 7 / 8 3 ZONE UOL SOURCE TYPE RATE CnL/hr) AUG.TRACER COHC. <pL/L) PMCH PDCH PDCB EXFILT. RATE ACPH IHFILT. RATE ACPH (f-F/hr) 1 215.0 PMCH 2 240.0 PDCH 3 204.0 PDCB 20HE-Z0HE 1-2 2-1 1-3 3-1 2-3 3-2 ZONE 1 IS 2ND FLR ZONE 2 IS 1ST FLR ZONE 3 IS BSHNT 3410 36.4 1878 15,4 1734 4.2 13.6 14.1 1.5 8.0 60 0.28 8.0 £7 0.28 16.6 43 0.21 RATE<H3/hr.> CATSU COHC.<pL/L) 9Q,4 152.3 7.5 2.7 13.1 68.4 890 889 ^88-887 885 884 883 PDCB 8.029 7.911 -?T403-7.907 -Hrfe-l-8.090 15.220 18.024 PMCH 34.139 38,592 3 0.02 73 0.31 94 a.46 -4-71-856-16.383 -9T-1-00-PDCH 13.942 13.328 - 1 5 T ^ 8 -14.418 4.068 4.271 13.109 15.170 2.475 2.566 and the avera'̂ e eyflltration and infiltration rates, expressed both in rP/^r and air changes per hour. >'ote, for example, that most of the fresh air infiltrating into the house is occurring via the basement and very little directly into the second floor. Below are the zone-to-zone air exchange rates and the individual CATS concentration data, which ranged ^rom 2 to 3^-parts per trillion. A summary view of the flox-? rates is s'-'cm in Figure 4. CATS 890, 889, and 888 were on the second floor in the small bedroom, master bedroom, and second small bedroom, respectively. The door to the latter room was closed and thus sampler 8^8 results vrere not used in t^e assessment of nixing and infiltration rates. GATS 887, 886, and 8«5 were located on the first floor in the family room, kitcher, and living roo-n, resfjectively. The kitchen location was near t'le hoodless range vent w'hich penetrated into the tasetnent; thus sampler P-̂-f- i-7as ̂ -iased and not tased in the naterial balance calculations. Table 5 shows a typical LriL/AIIlS Data Sheet which is completed by the user during a measurement period. The average temperature of the sources in each zone of the house or building must be recorded in order to correct for the effect of temperature on the source emission rate which is about 8% for a jOC change in temperature. Because of possible contamination of samplers during improper shipment or storage of the sources and samplers, a control or unused sampler is maintained, if not for every house, at least 2 or 3 for each deployment period in all buildings or homes. Proposed Use of 2I.'L/AI>iS in Buildings During a sampling period in a building, permeation-type PFT sources would be deployed uniformly throughout each zone of the structure, using a different type of tracer for each zone. At this time, three (3) tracer types are available; studies are being conducted to develop one or two additional types. Using PFT sources with high emission rates, i.e., about 30 to 60 nL/min, would allow one source to be deployed for every 5000 to 10000 ft^ of occupied space. If each zone of the building is equipped with an individual HVAC system and can be left running continuously during the testing, then the sources can be simply deployed in the return air plenum. Otherwise the sources should be placed uniformly throughout the zone. Samplers of the passive type would be deployed uniformly throughout the zone or floor of the building, with a minimum of three or four per zone or floor; one CATS would be left unopened as a control. Each CATS would sample for a designated period. The uniformity of the concentrations on a zone or floor would indicate the degree of mixing in that region and the differences between zones or floors would be used to calculate the average air exchange and infiltration rates. More detailed measurement of those rates could be provided with the use of the Brookhaven Atmospheric Tracer Sampler (BATS), a 23-tube programmable sampler. Set to collect one tube for an integrated 3-hour period, the 23 tubes would provide 69 hours of more continuous inform.ation. Both the cost 3 Zone 2nd Floor—1st Floor — Basennent 6 0 ^ 67 «• 4 3 ^ 2nd Floor (215 nn3) 0 .02 ACH 52 9 0 1st Floor (240 nn3) 0.31 ACH 6 8 Bosement ( 2 0 4 nn3) 0.46 ACH BROOKHAVEN HOUSE (Al l Flow Rates in nn3/h) Figure 4 73 i Account House Description 1 story 2 story w/basement split level w/fireplace w/woodstove TABLE 5 BNL/AIMS Data Sheet Zone No-vel. (m3,ft3) No. Sources *Avg. Temp. °f **Source Type No. Samplers Source Rate (BNL) House Code *Avg. Temp = (op x hrs + op x hrs) -J- 24 **Source Type = 1st letters or digit of source code TC 340 or 2-42-S60 Source Deployment: Deployed Time Removed Time Source No. Location (Order by zone) Zone Room Floor 1. Date Date Item Placed On Comments Collected 2. 3. 4. 5. 6. 7. 8. Remarks: Sampler Deployment: Uncapped Time Capped Time Sampler No. Location (Order by zone) Zone Room Floor 1. Date Date Item Placed On Comments Collected 2-3. 4. 5. 6. 7. 8. 9. C O N T R O L of the subsequent data analysis and interpretation as v/ell as the cost of the programmable sampler xrould increase the measurement cost. Costs for bNL/AIMS Deployment Currently this technique is not available commercially. On a limited basis, lirookhaven has interacted with federal, state, and private scientific and industrial groups working in the areas of energy performance evaluations and indoor air quality to provide this unique capability, where such appli-cation has resulted in advancement of the science of our understanding of such processes in buildings and homes. The cost of performing infiltration and air exchange measurements with SuL/AIliS has been estimated. For a home, the approximate cost is $45 per passive sampler per measurement period. Since a minimum of 2 and a maximum of 4 passive samplers are needed, the approximate cost to determine these average flov< rates is from $90 to $180 per home per measurement period. For buildings, which would require both greater involvement in planning and interpretation, the cost per sampler is estimated to be about $75 per CATS per measurement period. With a minimum of 4 samplers per floor or zone and for a 5-story building, a typical cost would be about $1,500. Measurements performed in greater detail using the programmable sampler would cost about the same per sample. But since more samples would be collected per measurement period, the total building cost is likely to be higher. The costs presented here are approximate costs for the use of the sources and samplers, both of which are reusable and remain the property of the supplier, and for analyses, data interpretation and reporting, and for any needed assistance in how to deploy the system. These costs do not include field deployment. This section is presented solely for the purposes of providing esti-mates for comparison with other techniques which are available either commercially or on a research basis. It should not be assumed that any potential user can purchase this service from Brookhaven. References 1. Dietz, R.M. and Cote, E.A. Air infiltration measurements in a home using a convenient perfluorocarbon tracer technique. Informal Report LNL 30797R, May 1982; Environ. Int. 8, 419-33 (1982). 2. Dietz, R.N. lirookhaven air infiltration measurement system (Birt^/AIMS): Manual for field deployment. Informal report BNL 31544, Feb. 1982. 3. Dietz, R.N., Goodrich, R.W. and Cote, E.A. Performance of a passive perfluorocarbon tracer system for building ventilation and air exchange measurements. BNL 33365, June 1983. For presentation at the Symposium on Measured Air Leakage Performance of Buildings, ASTM, Philadelphia, PA, April 1984. 

Brookhaven air infiltration measurement system (BNL/AIMS) description and application

Brookhaven air infiltration measurement system (BNL/AIMS) description and application

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