Field technicians
To facilitate communication of field issues and problem resolution, we're providing this list of important field-related items that all technicians should be aware of.
- If you have an immediate problem or question in the field, call Tech Support at 877-297-2797.
- If you have a question that is less urgent, you can send an e-mail to wapfieldquestions@ecw.org
IAQ study
1/17/11—Asbestos and blower door testing
Some programs and organizations place limitations on performing blower door tests when asbestos is present in a home. Temperature reduction in homes during blower door testing is also a concern in some situations. In our study, the following limitations apply:
- If friable asbestos (i.e. material that appears to be asbestos, and crumbles or produces dust when touched) is identified in a home, and would be exposed to the direct flow of air at an opening during blower door testing, then don’t perform blower door depressurization testing. If the use of positive pressurization testing would put the asbestos only in the path of air exiting the building, then positive pressurization testing can be substituted for depressurization.
- If vermiculite insulation is identified in an attic, don't perform attic zone testing with an attic-to-house hatch or other connection opened.
12/21/10—Unvented combustion appliances notes: ovens and dryers
Unvented gas dryers should be tested for CO production, similar to other unvented appliances. Don’t test if there are clothes in the dryer, and don't test if the dryer must be moved. Turn temperature to high, start dryer, and place combustion analyzer probe in dryer vent. Watch analyzer continually, and listen for burner shutoff. The objective is to take measurements after 3 minutes of burner operation, but if the burner shuts down earlier, take the final reading just before shutdown. Record CO and O2 in the table of Other Unvented Devices, and make a note of the burner-on time when measurements were made.
12/21/10—Whole-house fans in combustion spillage testing
Our standard test procedure for worst-case depressurization testing of combustion appliances is to leave whole-house fans OFF. Although these fans, if used with windows closed, are likely to dominate depressurization, they are generally intended for use as cooling ventilation fans with windows open.
12/21/10—Unvented combustion appliances notes: ovens and dryers
Gas oven carbon monoxide and oxygen should be measured using a combustion analyzer with the probe placed into the oven vent, which is usually a slot or grill on the panel behind the burners. These measurements may vary significantly across the width of the opening. Our standard measurement position is in the center of the opening.
Unvented gas dryers should be tested for CO production, similar to other unvented appliances. Don’t test if there are clothes in the dryer. Turn temperature to high, start dryer, and place combustion analyzer probe in dryer vent. Watch analyzer continually, and listen for burner shutoff. The objective is to take measurements after 3 minutes of burner operation, but if the burner shuts down earlier, take the final reading just before shutdown. Record CO and O2 in the table of Other Unvented Devices, and make a note of the burner-on time when measurements were made.
12/21/10—Blower door subtraction duct test
When performing a blower door subtraction duct test, the basement door should be in the same position as determined for basic blower door testing (i.e. open unless the basement was judged to be clearly outside the thermal envelope). If the basement is the primary zone of interest that contains ductwork, and the basement door is left open, then no zone pressure measurements need to be made during this test.
The filter should stay in place for this test.
12/21/10—Update: Treatment-group homes in the process of weatherization
Treatment-group homes in the IAQ study are not supposed to be weatherized until about a month after the first site visit (three months following the first site visit for control-group homes). However, we have run into a few cases where this plan was not completely communicated to agency staff, and weatherization work was either underway or planned for shortly after the technician site visit. If you encounter this situation, first see if it is still possible to delay weatherization until January (have agency staff contact Nick Sayen at 608-238-8276, ext. 115 if needed). If it is not possible to delay weatherization, then proceed with the site visit: we will include the home as a post-weatherization control.
12/9/10—Pressure Testing Procedures when Wood Stove or Solid Fuel Heater is Operating
When scheduling site visits, clients are asked to avoid using wood stoves for 24 hours before the scheduled time. They may not always comply, however, especially in cold weather. Performing depressurization blower door testing when a wood stove (or other solid fuel heater) is operating could result in drawing smoke and/or burning embers into the home, and is hazardous. Don't perform depressurization testing if a solid fuel combustion device is operating. If there is only a minimal fire or coals and no extra fuel in the stove, positive pressurization testing at 25 Pa can be used instead. Put wet newspaper over the fire and close inlet air vents. If the stove has a thermostat (e.g. as with some pellet stoves), turn it down. Turn off any combustion air blowers. Perform a single full-house blower door test at +25 Pa, but no zone pressure, pressure pan, or blower door subtraction test, even if otherwise applicable. Be careful the fire doesn’t flare up, which could ignite chimney creosote. If the fire is large, or there is a lot of fuel in the stove, don’t use the blower door at all.
If there is no fire in the solid fuel heater, make sure that ashes can't be pulled out of the stove during depressurization testing. This should include closing dampers and air vents, and putting wet newspaper over the ashes.
Watch solid fuel heaters for any problems that may occur while performing worst-case depressurization tests of other vented appliances.
12/9/10—Positive Pressure Blower Door Testing, Cold Weather Blower Door Testing
Some circumstances call for positive pressure blower door testing, e.g. asbestos in airflow stream, or wood stove with low fire. In these cases, blower door, zone pressurization, pressure pan, and blower door subtraction tests can all be performed. Be sure to enter the +/- signs in all pressure measurements and use the notes field to document that positive pressurization testing was used.
In general, blowers must be reversed in the door to allow accurate flow measurement in pressurization mode. Also, the reference pressure for measuring CFM flow through the blower must be the outdoor ambient air, not indoor air. (House pressure during testing should still be indoors wrt outdoors.) Check your blower door manual for more information on proper setup for positive pressurization testing.
When either positive or negative pressure blower door testing is done in cold weather, the technician must use judgment about how long the blower can be operated before cold air causes either health concerns or unacceptable comfort for occupants.
12/2/10—Review Schedule prior to Site Visits
Please review your schedule in detail as soon as it's available. The second tab in the spreadsheet (Call History Data) lists the primary heating fuel, type of heating plant, and whether the primary heating system is currently functional. If fuel oil is used, you should perform a smoke spot test before using a combustion analyzer (Bacharach recommends against using their analyzers if the smoke number is greater than 1). If you don’t have a smoke spot tester available, call the Tech Hotline and we may be able to lend one.
12/2/10—Wood Stove Testing
We DO NOT want to drill holes in wood stove vent pipe, and will not do SSE, CO, or draft testing of wood stoves. If a wood stove is the primary heating system (or is currently used as the main source of heat), we want to do a zone depressurization test in the zone where it operates. This would be a limited test of the worst-case zone depressurization only, and would not include firing the stove or draft pressure measurement. If the stove is operating during the test, make note of any observed spillage and room CO.
12/2/10—Combustion Analyzer Reminders
We've seen a number of issues regarding combustion analyzers; here are some reminders for proper operation:
- Know your carbon monoxide measurements BEFORE you start site visits. CO readings are critical to our IAQ study, but not all combustion analyzers measure CO. And check whether your analyzer provides air-free CO in addition to "raw" CO. Air-free is used when measuring gas ovens.
- Keep fresh batteries on hand, and/or make sure the rechargeable battery is fully charged each day. Low batteries can cause improper operation (e.g. failure to calculate efficiency).
- Make sure your analyzer is at room temperature well before it's to be used—don't leave in a cold car overnight if it's to be used in the morning. A cold analyzer can lead to condensation overflow and damage the sensors, plus throw off room temperature measurement.
- Keep condensate cleared. The condensate drain port MUST BE COMPLETELY CLOSED during use, because air entering at this port will throw readings completely out of whack.
12/2/10—Unvented Dryers
Please use notes fields to make note of any unvented gas or electric dryers. This can go on page 3 with misc appliance information, or anyplace that's convenient.
11/29/10—New IAQ data form
We have posted IAQ_DataForm_24.xls, also available under Resources at right.
11/24/10—Important Notes About Radon Canister Deployment
- Foundation-level radon canisters should be placed on the lowest accessible level of the home (including enclosed crawlspaces), regardless of whether it is finished or used. When deploying radon canisters in basements that have both finished and unfinished areas, locate the canister in a finished area, if possible.
- Main-living-level radon canisters should always be placed on the lowest regularly-occupied level of the home that is higher than the foundation-level canister. For example, if you encounter a split-level home with a basement in one section, a family room that is one-half level above the basement in another section, and additional living space that is a full level above the basement in another section, place the foundation-level canister in the basement, and place the main-living-level canister in the family room.
- Don't secure canister lids to canisters with tape, or tape canisters to their cardboard boxes. We received word from the processing lab that they have received some canisters with tape on them that is difficult to remove, or (worse) pulled off part of the label on the lid after the lid was taped to the canister. Lids should always be placed inside the cardboard box.
11/23/10—Updated IAQ protocol and form
If you were involved in November IAQ site visits, note that we have made some changes to both the protocol and the form. If you missed the 11/22 and 11/23 webinars (or just want to review what was covered in those), download and view IAQ Protocol Review for November under Resources at right.
Note that we will be posting the electronic version of the form (Version 24) on Monday, November 29. We will also post a revised Reference Manual.
11/23/10—Note on Hose Placement for Zone Pressure Diagnostics
When implementing zone pressure diagnostics, be sure to place hoses so that they are at least 5 feet beyond any openings and out of any substantial airflow path that might affect the pressure readings.
11/23/10—Note on Combustion Testing for Systems with Double-Walled Venting
Do not drill holes in double-walled (B-Vent) venting for measuring draft and CO. If there is no other access to measure draft pressure or flue products, omit the testing.
11/9/2010—Special Instructions for Mobile Homes
Download and review the file Mobile home guidance (also under Resources to the right) for special instructions related to testing mobile homes in the IAQ study.
11/09/10—Zone Pressure Testing
There is some confusion about the zone pressure testing protocol and form—and some errors on the form. Read on for clarification and instructions.
Describe the zones
The form provides for testing up to four zones: be sure to record what these are (e.g. "attached garage" or "attic") next to "Zone 1", "Zone 2" etc. in the top section of the form, and be consistent about those zones for the remainder of the form. In other words, if you list Zone 1 as an attached garage at the top of the form, the subsequent measurements for the attached garage should be listed on the Zone 1 line elsewhere on the form.
We have set up the electronic version of the form so that whatever is described as Zone 1 in the top section will automatically appear in the other sections. You shouldn’t need to change these, but if you do, you can simply type over what appears for the Zone descriptions.
If you are having trouble entering data descriptions, you are using an old version of the form that has some errors in it (sorry!). Download the most recent version of the form under Resources on the right under IAQ study (form name: IAQ_DataForm_xx.xls where xx is a version number).
How to test basements
First, be sure to read the note on the form about the "normal" position of the basement door, because this affects how the tests are conducted. In most cases, the basement door should be treated as normally-open. However, if the basement can be considered to be clearly outside the thermal envelope of the house (e.g. basement ceiling is insulated) and the basement door would logically be kept closed to keep the cold out, the basement door should be listed as normally-closed on the form.
Basement door treated as normally-open (common situation)—Follow the form directions for basement testing. However, we omitted one important data line for a basement zone test where it is possible to make an exterior opening from the basement to the outside by opening a basement windor or door to the outside. We'll correct this starting in December. In the meantime, if it is possible to test the basement zone by creating an exterior opening, close the basement door, create the exterior opening, and record the readings on the Zone 4 line at the bottom of the form. (If you already have Zone 4 assigned to something else, record the information under Notes.)
Basement door treated as normally-closed (uncommon situation)—Skip the directions and data lines for the basement on the form. Instead list the basement as Zone 1, and follow the standard zone testing protocol.
No basement door—If there is no basement door (i.e. no way to isolate the basement from the rest of the house), omit basement zone pressure testing entirely.
11/09/10—Range/Oven CO Testing
If a range burner or oven yields an initial CO reading that is above the hazard-notification level (100 ppm for ovens; 50 ppm for burners), take a second reading after an additional 3 minutes. Complete the Notification of Possible Hazards form if the second reading is also above the hazard-notification level. Record the CO and O2 values for first reading on the main part of the form, and the second readings under Notes.
When testing burners, measure six inches above the flame after allowing for a three-minute burner warm-up. After placing the probe, allow about 20 seconds for the analyzer to purge, then take an immediate reading: there is no need to hunt around for a maximum reading.
11/09/10—Pressure-Pan Testing
Some registers are difficult to seal off with a standard pressure pan. Carry an old pillow to press against the register for these (be sure to check that the pillow is completely pressed against the register. Alternatively, registers may be sealed with duct mask.
Be sure to describe registers on the form in enough detail that someone else can match up the listed registers for the post-weatherization site visit.
Be sure to list all registers, even those that you cannot access to test.
11/05/2010—Digital data entry
We have posted IAQ_DataForm_19.xls. We unlocked several cells in IAQ_DataForm_19.xls to allow users to enter area descriptions for foundation-level and above-grade moisture observations. Also note that "post" data fields have now been locked. Digital version 19 can be used for entry of data collected on paper versions 16 through 19.
10/21/10—"NA" in field form data entry
When keying field-form data into the Excel spreadsheet, avoid entering "NA" or other text indicators that a numeric value is not applicable: simply leave the cell blank.
Bulk fuel studies
OIL
10/21/10—Tight wiring
It is proving difficult to fit the current switch for tracking heating system run time into tight enclosures for some heating systems. Please make sure that there is no risk of electrocution or of parts vibrating loose if you cannot completely re-secure enclosures after installing the logging equipment.
PROPANE
10/21/10—Two stage heating systems
We have already run into a propane site with a two-stage furnace. These will have multiple Btu/hr input values on the nameplate. In order to properly estimate fuel consumption, each stage needs to be monitored separately. There is usually a wire to the gas valve that goes live when the system is firing in low- or high-stage, and another wire that goes live just for high-stage. Try to identify these wires and install a current switch and separate state logger on each. When in doubt, contact tech support at 877-297-2797. Remember that setting up proper tracking of heating system operation is the most important task in the field for the oil and LP studies!
OIL AND PROPANE
10/21/10—Treatment-group homes in the process of weatherization
Treatment-group homes in the oil and LP studies are not supposed to be weatherized until the month January. However, we have run into a few cases where this plan was not completely communicated to agency staff, and weatherization work was either underway or planned for shortly after the technician site visit. If you encounter this situation, first see if it is still possible to delay weatherization until January (have agency staff contact Claire Cowan at 608-238-8276, ext. 117 if needed). If it is not possible to delay weatherization, then proceed with the site visit: we will shift the site from the treatment group to the control group. Either way, please note the circumstances on the field form.
10/21/10—"NA" in field form data entry
When keying field-form data into the Excel spreadsheet, avoid entering "NA" or other text indicators that a numeric value is not applicable: simply leave the cell blank.
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