Module 10 - Air leakage.pptx

STRAND Energy-Star Training Minneapolis Blower Door– Setup and Testing © 2023 STRAND Dallas I Texas 972 620 8204 © 2023 STRAND Dallas I Texas 972 620 8204 © 2023 STRAND Dallas I Texas 972 620 8204 The blower door fan consists of a molded fan housing with a 3/4 horsepower permanent split...

STRAND Energy-Star Training Minneapolis Blower Door– Setup and Testing © 2023 STRAND Dallas I Texas 972 620 8204 © 2023 STRAND Dallas I Texas 972 620 8204 © 2023 STRAND Dallas I Texas 972 620 8204 The blower door fan consists of a molded fan housing with a 3/4 horsepower permanent split capacitor AC motor. Air flow through the fan is determined by measuring the pressure at the flow sensor which is attached to the end of the motor. When the fan is operating, air is pulled into the inlet side of the fan and exits through the exhaust side (a metal fan guard is bolted to the exhaust side of the fan). The blower door fan can accurately measure airflow over a wide range of flow rates using a series of calibrated flow rings which are attached to the inlet of the fan. The standard Minneapolis Blower Door System comes with two flow rings (A and B), and optional flow rings are C, D and E. © 2023 STRAND Dallas I Texas 972 620 8204 Where to Install the Blower Door Frame • It is always best to install the blower door system in an exterior doorway of a large open room. • Try to avoid installing the fan in a doorway where there are stairways or major obstructions to air flow very close (one to five feet) to the fan inlet. • If the doorway leads to a porch or garage, make sure this space is open to the outside by opening doors and/or windows. • The door frame is almost always installed from the inside of the building and may be installed in place of the prime door, the storm door or anywhere in between. • Always open the inside door and outside storm door as much as possible during the test to prevent restrictions to airflow. © 2023 STRAND Dallas I Texas 972 620 8204 Temporarily install the frame in the doorway » Stand the frame up and put into the doorway. » Loosen all of the adjustment knobs. » Place one foot on the bottom of the frame to hold it place, and extend the top of the frame to the top of the doorway, leaving about a fingers width of space between the top of the frame and the top of the doorway. » Tighten the knobs on the vertical pieces. » Extend the frame horizontally so both vertical pieces fit into the doorway, leaving about a fingers width of space between the vertical pieces and the sides of the doorway. » Tighten the knobs on the horizontal pieces © 2023 STRAND Dallas I Texas 972 620 8204 Attach the nylon panel to the frame and install into doorway » Lay the fabric panel on the floor, with the Velcro straps and blower door logo facing up. » Remove the frame from the doorway, being sure the adjustment knobs are still tightened so the frame doesn’t adjust in size. » Lay the frame onto the fabric door panel, lining up the top and bottom horizontal pieces with their respective Velcro straps. » Drape each side of the panel over the frame snugly and tighten the Velcro straps. © 2023 STRAND Dallas I Texas 972 620 8204 » Stand the frame up near the doorway and run the green tubing outside so the end is well away from the nylon panel. Extend the other end through one of the patches at the bottom corners of the nylon panel. Pull just enough of it to the inside so it can make the connection to the gauge. » Readjust the frame so it fits snuggly in the door opening and tighten all four adjustment knobs. Now engage all four cam levers so the frame is secured tightly in the opening. » Install the crossbar with the Velcro strap in the lowest slot above the fan hole and tighten the knob so it fits snug. Engage the cam lever © 2023 STRAND Dallas I Texas 972 620 8204 Insert the blower door fan into the hole in the fabric panel » Set the fan down in front of the panel. For a depressurization test, the side of the fan with the guard should be facing outside. The side of the fan with the flow rings should be facing inside. (For a pressurization test, insert the fan the other way, with the guard inside the house and the flow rings outside the house.) » Insert the fan bottom first into the hole, and then work the elastic around the fan until it’s completely inserted. » The top of the hole should rest in the middle of the electrical box on top of the fan so the plug inlet and handle are not covered. » The bottom of the fan should be resting on the lower horizontal frame piece. » Slip the velcro strap through the fan handle and loop it up and back around the cross bar. © 2023 STRAND Dallas I Texas 972 620 8204 Attach the gauge mounting board » The mounting board for the gauge can be attached to any door by using the C-clamp connected to the back of the board. » The mounting board can also be easily attached to a horizontal surface (book shelf or desk top) by rotating the clamp 90 degrees before securing the board. » The mounting board can be attached to the gauge hanger bar. Connect the gauge hanger bar to either side of the vertical pieces by inserting the hook into one of the remaining slots. Tighten the mounting board clamp onto the hanger bar © 2023 STRAND Dallas I Texas 972 620 8204 Attach the fan speed controller to the bottom of the gauge mounting board by sliding it on using the metal clamp on the back of the controller. • Insert the female plug from the fan speed controller into the receptacle located on the fan electrical box. Make sure the plug is inserted completed as the plug or receptacle can overheat. • Plug the power cord into an AC outlet that is compatible with the voltage of the fan motor and speed controller. Be sure the controller knob on the fan speed controller is turned all the way counter clockwise to the off position before plugging in the power cord © 2023 STRAND Dallas I Texas 972 620 8204 Setting Up the Building for the Test The following preparations are appropriate when using the blower door to determine retrofit airsealing potential, weatherization effectiveness or estimating natural infiltration rates. If the purpose of the blower door test is to document construction airtightness quality for new houses, additional preparation may be needed. Your program guidelines may require you to prepare the building differently than described below. © 2023 STRAND Dallas I Texas 972 620 8204 Adjustable Openings • Close all storm and prime windows. • Close all exterior doors and interior attic or crawlspace hatches which are connected to conditioned spaces. Also close exterior crawl space hatches and vents if they are normally closed most of the year. • Open all interior doors to rooms that are conditioned. The object here is to treat the entire building as one conditioned space and to subject all of the leaks in the building to the same pressure difference. Because few house basements can be completely sealed from the house and usually some conditioning of the basement is desirable, they are typically included as conditioned space. • Tape plastic over window air conditioners if they appear to be a source of air leakage into the building and they are typically removed during a large part of the year © 2023 STRAND Dallas I Texas 972 620 8204 Combustion Appliance/Exhaust Devices • Adjust all combustion appliances so they do not turn on during the test. This is commonly done by temporarily turning off power to the appliance, or setting the appliance to the “Pilot” setting. If combustion appliances turn on during a depressurization test, it is possible for flames to be sucked out of the combustion air inlet (flame rollout). This is a fire hazard and can possibly result in high CO levels. • If there are attached spaces (e.g. townhouses) that could contain a vented combustion appliance, either adjust those appliances to prevent them from turning on during the test, or be sure that the attached spaces are not depressurized or pressurized when the Blower door is operating. • Be sure that fires in fireplaces and woodstoves are completely out. Take precautions to prevent ashes from being sucked into the building during the test. In most cases it will be necessary to either tape doors shut, clean out the ashes, and/or cover the ashes with newspaper. • Turn off all exhaust fans, vented dryers, air conditioners, ventilation system fans and air handler fans. © 2023 STRAND Dallas I Texas 972 620 8204 After the Test Be sure you have returned the building to its original condition before leaving. This includes turning the thermostat and water heater temperature controls to their original setting. Always check to see that furnace, water heater and gas fireplace pilot lights have not been blown out during the blower door test (re-light them if necessary). Remove any temporary seals from fireplaces, woodstoves or other openings sealed during the test. In addition, combustion safety tests should usually be performed before leaving the house. © 2023 STRAND Dallas I Texas 972 620 8204 Finding Air Leaks There are many techniques that are used to find air leaks with the blower door. Air leaks between the interior and exterior of the building often follow long and complicated leakage paths. Typically, the air sealing goal is to find where the leaks cross the exterior envelope of the building and to concentrate sealing activities on those areas. © 2023 STRAND Dallas I Texas 972 620 8204 Using Your Hand The easiest method and one that is used most often is to depressurize the building and walk around the inside, checking for leaks with your hand. When you are looking for leaks, let the blower door fan run at a speed which generates between 20 and 30 Pascals of building pressure. You should get in the habit of always using the same pressure so you will get a good feel for what is a big leak and what is not. An entire room can be checked quickly if there is a door between it and the rest of the house. Standing just outside of the room, close the door most of the way, leaving about a one inch crack. A large blast of air coming through this crack indicates large leaks between that room and the outdoors. © 2023 STRAND Dallas I Texas 972 620 8204 Using a Chemical Smoke Puffer In houses, many of the most important leaks are found between the house and the attic or between the house and a ventilated crawlspace. These leaks usually will not be easy to find unless you physically go into the attic or crawlspace. The use of a handheld smoke puffer is often helpful in these areas. With the house depressurized (and the crawlspace or attic access door shut), you can squirt small puffs of smoke toward suspected leakage sites from the attic or crawlspace and watch to see if the smoke gets sucked into the leak. With a piece of tubing attached to the smoke puffer, you can often reach deep into corners or in hard to reach spots. A smoke puffer or a pressure pan is a necessity when looking for leaks in the forced air ductwork © 2023 STRAND Dallas I Texas 972 620 8204 • Using an Infrared Camera The ideal technique for finding leaks is to use an infrared scanner with a blower door. This procedure usually involves performing two infrared scans from the interior of the building; one before turning on the blower door and one after the blower door has been depressurizing the building for five to 10 minutes. As long as the air being sucked in through the leaks is either warmer or colder than the interior of the house, the area surrounding the leakage path will change temperature and show up on the infrared scanner screen. Even if there is little temperature difference between inside and outside, an infrared scan may still be possible if the attic space has been warmed from solar radiation on the roof or the crawlspace has been cooled from the ground. A temperature difference of about five to 10 degrees is sufficient to expose the important leaks. This technique often allows you to find significant leaks without having to enter the attic or crawlspace. © 2023 STRAND Dallas I Texas 972 620 8204 Other Diagnostic Techniques Many important air leaks in a building are not direct leaks to the outside. Air leaks often follow complicated paths through building cavities and through unconditioned zones (such as attics, crawlspaces or garages) on their way into or out of the building. Attic bypasses, found in many houses, are a good example of a series leak. Air leaving the house first must flow through the ceiling/attic boundary and then through the attic/roof boundary before exiting the house. © 2023 STRAND Dallas I Texas 972 620 8204 Diagnostic procedures have been developed to analyze series leakage. These procedures, called zone pressure diagnostics (ZPD), are widely used by weatherization professionals to prioritize airsealing efforts in houses by estimating the amount of air leakage from attached zones (e.g. attics, crawlspaces, garages and basements). ZPD techniques typically combine blower door airtightness test results with zone pressure measurements made both before and after an opening or hole has been added to one surface of the zone being tested. Duct leakage to the outside can add to your overall airleakage values during a blower door test. One method of finding those leaks is using a pressure pan. You may also quantify the leakage to the outside by using theblower door subtraction method © 2023 STRAND Dallas I Texas 972 620 8204 Using the Can’t Reach 50 Factor: One-Point Test If you were performing a one-point test and the blower door fan was unable to depressurize the building by approximately 50 Pascals because one of the flow rings was installed, remove the ring and repeat the test (removing the flow ring will increase the maximum air flow available from the fan). If you were not able to depressurize the building by approximately 50 Pascals (with the “open fan” running at full speed) because the building is extremely leaky, use the following instructions © 2023 STRAND Dallas I Texas 972 620 8204 For DG-1000 and DG-700 Users No adjustments to the test procedure above are necessary other than to make sure the gauge was in the PR/ FL @50 mode during the one-point test. If you can not achieve the target test pressure of 50 Pascals because the building is extremely leaky, a CFM50 leakage estimate will automatically be displayed on Channel B. The leakage estimate shown on Channel B is determined by continuously adjusting the measured air flow from the blower door fan to a test pressure of 50 Pascals, using the real-time Channel A building pressure reading and the can’t reach 50 factors shown below. © 2023 STRAND Dallas I Texas 972 620 8204 © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a one-point Depressurization test Before the Test • Install the blower door frame, panel and fan into an exterior doorway. For instructions about how to do this, please see Chapter 2 of the Minneapolis Blower Door User Manual. • Prepare the building for the blower door test. For instructions about how to do this, please see Chapter 3 of the Minneapolis Blower Door Manual. © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a one-point Depressurization test Tubing Hookup 1. Attach one end of the green tube to the Channel A reference tap. Run the other end of the tubing outside through one of the holes provided in the lower corner of the nylon panel and away from the flow of the fan. 2. Attach one end of the red tube to the Channel B input tap. Attach the other end of the red tube to the pressure tap on the blower door fan. Note: For help with how to connect the tubing to the DG-1000, please use the Tubing Assistant on our website © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a one-point Depressurization test Conducting the Test 1. Turn on the DG-1000 gauge by pressing and holding the power button for a few seconds 2. After the Home screen loads, touch Gauge to open the Gauge app 3. Touch the mode area to open the Channel B Settings menu. Select Flow @50. Touch device and then select Model 3 Fan. Touch the arrow in the upper left of the screen to return to the Gauge app screen. © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a one-point Depressurization test 4. With the fan inlet still covered, touch Set Baseline to initiate the building baseline measurement procedure on Channel A. 5. During a baseline measurement, Channel A will display a long-term average baseline pressure reading while Channel B is used as a timer in seconds to show the elapsed measurement time. When you are satisfied with the baseline measurement, touch enter and enter the baseline reading into the gauge. 6. Channel A will now display the baseline adjusted building pressure value. 7. Remove the No-Flow Plate from the Blower Door fan and install the flow ring which you think best matches the needed fan flow (see table below. © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a one-point Depressurization test Using Cruise Control 1. Turn the blower door speed control knob to the “just on” position (the controller is on but turned all the way down). 2. Set the cruise target by touching the Cruise menu and selecting 50 Pa. Note: The fan control cable must be connected to the DG-1000 and the fan speed controller for this feature to work. 3. Touch the green play icon to start cruise. Once cruise is started, the fan speed slider will move on it’s own. The green play icon will change to an X, and a red stop icon will appear in the lower right of the screen. A pop-up will appear at the bottom of the screen to indicate that cruise has started © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a one-point Depressurization test 4. The blower door fan will now slowly increase speed until the building depressurization displayed on Channel A is approximately –50 Pa. 5. Cruise will turn off when the X is touched, but the fan will continue running. When the X is touched, a pop-up will appear at the bottom of the screen that says “Cruise canceled.” Touch the red stop icon in the bottom right corner of the screen to stop the fan. When the fan is stopped a pop-up will appear at the bottom of the screen that says “fan stopped © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a one-point Depressurization test 5.1 Controlling the Fan with the Gauge app Touch and slide the dot on the fan speed slider in the Gauge app to adjust the fan speed using the DG-1000. As the fan speed increases, the building depressurization displayed on Channel A should also increase. Continue to increase the fan speed until the building depressurization shown on Channel A is between –45 and –55 Pa. © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a one-point Depressurization test 5.2 Manually Controlling the Fan Gradually increase the fan speed by slowly turning the fan controller clockwise. As the fan speed increases, the building depressurization displayed on Channel A should also increase. Continue to increase the fan speed until the building depressurization shown on Channel A is between –45 and –55 Pa © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a one-point Depressurization test 6. Channel B will display the one-point 50 Pa leakage estimate. Record this number. If the leakage estimate is fluctuating more than desired, try changing the time average setting on the gauge by touching the Time Average menu and choosing the 5 or 10 second or long-term averaging period. 7. Turn off the blower door fan. If you are using cruise control, this is done by touching the red stop icon in the Gauge app © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a one-point Depressurization test 8. “-----” or “LOW” appearing on Channel B • Whenever “-----” or “LOW” appears on Channel B in the Flow @ 50 mode, the gauge can not calculate a reliable leakage estimate. The messages “-----” and “LOW” appear on Channel B under the following conditions: » “-----” is continuously displayed when the building test pressure from Channel A is below a minimum value of 10 Pa. Estimating building leakage results when the test pressure is below this value may result in large errors. If possible, install a larger flow ring or remove the flow rings to generate more fan flow. Be sure the fan is off when changing flow rings. » Channel B reads “LOW” is continuously or LOW alternates with a flow reading when the air flow reading through the device is unreliable (i.e. you are trying to measure a flow outside of the calibrated range of the test device in its current configuration). If possible, you should change the test device configuration to match the flow rate being measured (e.g. install a flow ring or a smaller flow ring). Be sure the fan is off when changing flow rings. © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a one-point Depressurization test © 2023 STRAND Multi-Point Test A multi-point blower door test is conducted at several different pressure points. The ANSI/RESNET/ICC 3802019 standard requires testing at a minimum of five different pascals of pressure between 10 pascals and 60 pascals. The airflow data is collected over a minimum of 10 seconds at each of the pressure intervals. Manufacturers make software designed to perform these tests to the required standard; for example, The Energy Conservatory’s Auto Test software (which currently operates only on phones and tablets) has several multi-point test options. One of the options is the RESNET 380 multi-point test mentioned above. For that test, the pressure points are 60 Pa, 48 Pa, 35 Pa, 23 Pa, and 10 Pa. Another option in the software is the ASTM E779 multi-point test (another testing standard allowed by the IRC). There are eight different pressure points in this automated test: 60 Pa, 54 Pa, 48 Pa, 42 Pa, 36 Pa, 30 Pa, 24 Pa,Dallas andI 18 TexasPa. 972 620 8204 © 2023 STRAND Conducting a Multi Point Depressurization test Multi-Point Test A multi-point blower door test is conducted at several different pressure points. The ANSI/RESNET/ICC 380-2019 standard requires testing at a minimum of five different pascals of pressure between 10 pascals and 60 pascals. The airflow data is collected over a minimum of 10 seconds at each of the pressure intervals. Manufacturers make software designed to perform these tests to the required standard; for example, The Energy Conservatory’s Auto Test software (which currently operates only on phones and tablets) has several multi-point test options. One of the options is the RESNET 380 multi-point test mentioned above. For that test, the pressure points are 60 Pa, 48 Pa, 35 Pa, 23 Pa, and 10 Pa. Another option in the software is the ASTM E779 multi-point test (another testing standard allowed by the IRC). There are eight different pressure points in this automated test: 60 Pa, 54 Pa, 48 Pa, 42 Pa, 36 Pa, 30 Pa, 24 Pa, and 18 Pa. Dallas I Texas 972 620 8204 Conducting a Multi Point Depressurization test One reason for conducting a multi-point test is that it is more accurate for predicting building leakage at lower pressures. During normal operating conditions, a typical home rarely sees 50 pascals of pressure difference between inside and outside. More commonly, the pressure difference will be under 10 pascals. To predict the leakage rate at lower pressures, a building leakage curve is produced after a multi-point test is completed (see graph, above). Though the building leakage curve can be estimated using a single-point blower door test, the curve is more reliable when a multi-point test is used. The test performed in the example above was an ASTM E779 multi-point test. The leakage rate at 60 pascals was 806 cfm, and at 18 pascals, 339 cfm. The curve shows us the predicted leakage rates down to a difference of 4 pascals of pressure. © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a Multi Point Depressurization test What happens if you are unable to reach at least 50 pascals of pressure during multi-point testing? The 380 standard will allow a multi-point test to be used as long as at least 25 pascals of pressure can be reached. Less than 25 pascals and the test is required to be a single-point test. Most current software options will convert the test results when a “can’t reach 50” test occurs © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a Multi Point Depressurization test Returning to the point that more data means more accuracy, both single-point and multi-point blower door test results are only as good as the information provided for the calculations. If you are conducting a test during the winter in a very cold climate, you will need to account for the difference in temperature between inside and outside the home, or if you live in a mountainous area, elevation needs to be accounted for. Another important piece of information is the baseline pressure (normal difference in pressure between inside and outside the building). When you’re performing an automated test using software, the software will perform a quick baseline test and automatically adjust the fan speed to account for the pressure difference. When performing a manual test, you will need to do the calculations by hand and make the adjustments manually. © 2023 STRAND Dallas I Texas 972 620 8204 Conducting a Multi Point Depressurization test There are many reasons to perform a blower door test. Sometimes we want to perform the most accurate test we can; other times we just need to run the blower door to help us find the holes. Having a basic understanding of the differences between a single-point and multi-point test can help you decide which test to perform. The only time I perform single-point testing is to confirm the leakage rate of a structure before setting the fan on cruise control to find the air leaks. In all other situations, I perform multi-point tests. © 2023 STRAND Dallas I Texas 972 620 8204