North Dakota Weatherization Field Standards
Contents
1. 4 Record any pressure difference between the main body of the dwelling and the outdoors This is the reference background pressure a Areference background pressure might be due to stack effect air leakage especially if it is cold outdoors or wind 5 Turn on the air handler and measure the pressure of the main body of the house with reference to the outdoors a If the pressure difference between the main body and the outdoors is different with the air handler on than with the air handler off there is probably some duct leakage to the outdoors i Either from the return side of the system the pressure difference of the dwelling with reference to outdoors will move toward positive when the air handler is activated or ii From the supply side of the system the pressure difference of the dwelling with reference to outdoors will move toward negative when the air handler is activated 6 Close all interior doors North Dakota Weatherization Field Standards January 2003 Page 115 11000 Diagnostic Testing Procedures 7 Repeat the pressure measurement from the main body of the house with reference to the outdoors a If this pressure is different than it was when all the interior doors were open the interior doors are acting as dampers to the air distribution system This can cause thermal discomfort and stuffiness in the room and it can increase the air leakage of the dwelling when the air handler is running 8 Take the pr2. the pressure pan readings is between 3 and 5 Pascals Visually check all boots and repair and seal with mastic if necessary Visually check any crossover ducts and repair and seal with mastic if necessary Make sure these ducts are supported properly Visually check furnace plenum joint and repair and seal with mastic if necessary and Goal Reduce the sum of pressure pan readings to 3 Pascals or less For a living space return system if the sum of the pressure pan readings is greater than 5 Pascals Repair and seal as in 3 above and Perform duct blower test and implement duct blower guided duct repair and sealing Refer to page 121 Duct Blower Testing Goal Reduce duct leakage to the outdoors as measured with a duct blower and blower door to10 percent of conditioned floor area 11922 Site Built Homes Including Manufactured Housing 1 For ducts located in unconditioned spaces The pressure pan readings must be adjusted for house zone pressure differences See Pressure Pan Multipliers chart and test on page 120 for instructions North Dakota Weatherization Field Standards January 2003 Page 117 11000 Diagnostic Testing Procedures a If possible convert the unconditioned space where the ducts are located to a conditioned space making sure the air and thermal barriers are installed effectively i Demonstrate the effectiveness of this weatherization work by performing a house to zone pressure and flow tes
3. North Dakota Weatherization Field Standards Home Weatherization Assistance Program January 2003 Edition State of North Dakota Department of Commerce Division of Community Services DCS Paul Govig Director Energy Division Howard Sage Weatherization Program Administrator 400 East Broadway Bismarck ND 58502 701 328 4140 11000 Diagnostic Testing Procedures 11800 Room to Room Pressure Testing 11810 Air Handler Pressure Balance Testing for Site Built Homes 11811 Introduction This test procedure is performed only in dwellings with air handlers Room to room pressure s should be measured in all rooms with forced air heating return or supply ducts and operable doors after all weatherization installations have been completed The procedure indicates the magnitude of 1 Duct leakage to the outdoors either through supply or return ducts 2 Imbalances of air distribution resulting from closed interior doors These closed doors can act as dampers to the free flow of air within the conditioned space of the dwelling 3 Imbalances of air distribution resulting from airflow differences between the supply side and return side of the ductwork for example a restricted return truck 11812 Test Procedure 1 Set house up in winter operating mode 2 Run a pressure hose from the main body of the house to the outdoors 3 Setup amagnehelic gauge zeroed at 15 Pa or a digital pressure gauge in the main body of the house
4. an reading with the maximum possible reading 12 Record the pre and post weatherization readings on the Diagnostic Field Form 11940 Duct Blower Testing for Leakage to Outdoors 11941 Introduction This required duct blower test requires measurement of duct air leakage to the outdoors not total duct leakage to outdoors and indoors During this test procedure a blower door fan will be used to pressurize the building to the test pressure while the duct blower system is used to pressurize the duct system to the same pressure as the building Because the duct system and the inside of the dwelling will be at the same pressure there will be no leakage between the ducts and the dwelling during the test The blower door fan should be set up to blow air into the building for pressurization Airflow through the blower door does not need to be measured during this test Because of this the blower door fan can either be set up in the pressurization test mode or it can be set up in the standard depressurization test mode with the fan direction switch reversed to blow air into the dwelling Refer to your blower door manual for complete instructions For residential duct systems generally is recommend as the test pressure This pressure has been adopted by the majority of residential duct testing programs in the U S because 25 Pascals represents a typical operating pressure seen in many residential systems The instructions below assume the us
5. atherization Field Standards January 2003 Page 122 11000 Diagnostic Testing Procedures b Turn the mode selection knob to fan select and select 8 Choose 8 0 for no duct blower rings 8 1 for one ring and so on c Turn the mode selection to pressure 20 Turn on the duct blower and pressurize the ducts until the gauge reads zero that is the pressure between the duct system and the dwelling is zero Leave the duct blower running 21 Re check the building pressure at the blower door and adjust if necessary 22 Re check the duct blower system and adjust if necessary 23 On the DG 3 digital manometer connected to the duct blower fan turn the channel knob to B and turn the mode switch to Flow The gauge will now display the air flow through the duct blower fan in cubic feet per minute at 25 Pascals CFMgs This fan flow is the measured duct leakage to the outdoors at the test pressure of 25 Pascals This CFMzs5 flow can also be determined by reading fan pressure from Channel B and converting that pressure reading to flow by using the Duct Blaster Flow Conversion Table in the Duct Blaster instruction manual 24 Check to make sure you have set the DG 3 correctly 25 It is a good idea to move the register pressure hose to other registers If the dwelling to duct pressure does not remain close to zero there are probably significant duct leaks Inspect and repair any obvious duct disconnects bef
6. e home ducts and site built homes with ductwork in crawl spaces or attics are susceptible to leakage to and from the outdoors On the other hand although duct leakage within the conditioned envelope usually does not have a significant energy impact it might impose a hazard to occupant health by causing poor indoor air quality or backdrafting of combustion North Dakota Weatherization Field Standards January 2003 Page 116 appliances 11000 Diagnostic Testing Procedures These potential problems are addressed on site by an IAQ appraisal and by performing the worst case draft test refer to page 111 Pressure pan and duct blower testing must be done in some dwellings to determine if ducts are leaking to a significant degree to or from the outdoors 11920 Duct Leakage Standards The following standards shall be followed for mobile homes including double wide mobile homes and site built homes including manufactured housing 11921 Mobile Homes 1 2 a b 3 a 4 a b If there is a belly return system in the mobile home convert it to a living space return system refer to Section 7700 on page 79 For a living space return system if the sum of the pressure pan readings is 3 Pascal or less Visually check furnace plenum joint and repair and seal with mastic if necessary and Visually check all boots and repair and seal with mastic if necessary For a living space return system if the sum of
7. e of The Energy Conservatory Digital Manometer Model DG 3 and the Minneapolis Duct Blaster 11942 Test Procedure 1 Close all exterior doors and windows 2 Open all interior doors 3 Open doors to heated or conditioned spaces Close doors to all unconditioned spaces 4 Install blower door properly North Dakota Weatherization Field Standards January 2003 Page 121 11000 Diagnostic Testing Procedures 5 Shut down solid fuel appliances before activating blower door or duct blower 6 Adjust the HVAC system controls so that the air handler fan will not turn on during the duct blower test 7 Temporarily seal off all supply and return registers except any central return grille being used to connect the duct blower system to the duct system 8 Temporarily seal off all combustion air and ventilation air inlets that are directly connected to the duct system 9 Turn off all exhaust fans vented dryers and room air conditioners 10 Turn off all vented combustion appliances if there is a possibility that the space containing the appliance will be depressurized during the duct blower test 11 Remove all filters from the duct system and air handler cabinet If the duct blower will be installed at a central return grille remove the filter from that grille 12 If ducts run through unconditioned spaces such as attics garages or crawlspaces open vents access panels or doors between these spaces and the outdoors to el
8. essure gauge being careful to level and zero on 15 Pa when using a magnehelic gauge and measure the pressure difference across all interior doors Pressure test and record measurements for all rooms with reference to the main body of the house Make sure that registers and grilles are not blocked even though they appear open Provide pressure relief to any room with readings greater than 3 Pascals by b Opening the door slightly while measuring the pressure difference across the door Open the door until the pressure difference is less than 3 Pascals and measure the square inches of opening This is the number of square inches i The door must be undercut this usually works well in mobile homes ii A direct grille offset grilles or jump duct must be to properly relief the pressure imbalance caused by the distribution system when the door is closed 9 Turn off air handler and return house to the condition it was in before testing began 11900 Duct Leakage Testing 11910 Introduction Duct leakage can lead to many problems in a dwelling the most common one being wasted energy Other problems can include thermal discomfort substandard indoor air quality and combustion venting failure Ductwork leakage can take place 1 within the confines of the conditioned envelope of the building or 2 to and from the outdoors Leakage to or from the outdoors wastes more energy than leakage within the confines of the thermal envelope Mobil
9. g the filter with the bag over it This blocks the filter opening and results in more accurate pressure pan testing When the testing is completed make sure to remove the plastic bag from around the filter 4 Temporarily seal outside combustion air inlets or ventilation system connections that are directly connected to the duct system These connections will show up as large leaks if not sealed prior to testing If supply ducts are located in a garage or other unconditioned space seal these registers so that the register opening does not show up as a duct leak 5 Open attics crawl spaces garages and other unconditioned spaces to the outdoor air as much as possible If the basement is being treated as an unconditioned space open it to the outdoor air 6 Only one person at a time should be taking pressure pan readings Having 2 registers in different parts of the duct covered by a pressure pan at the same time can affect readings 7 Depressurize the dwelling to 50 Pascals with the blower door 3 This section is primarily based on Using a Pressure Pan to Diagnose Duct Leakage by The Energy Conservatory March 2002 This document is available on the Internet at www energyconservatory com manuals html When you get to this page find Pressure Pan User Manual Before fully opening or changing the position of balancing dampers mark their position so that they can be returned to that position after the pressure pan testing Nor
10. iminate pressure changes during the test procedure This should also be done if the duct blower fan will be installed in an unconditioned space for example connected to an air handler in a garage or crawlspace 13 On the blower door connect the outdoor building pressure tube to the bottom tap on the 60 Pascal magnehelic gauge The other end of this tubing should either be run to the outdoors or to the unconditioned zone which contains the majority of the ductwork 14 Install the duct blower at the furnace or at a large return grille 15 Decide on the ring configuration for the duct blower 16 Connect the digital manometer correctly a Connect a pressure hose between a register and the input tap on side A of the digital pressure gauge Connect another pressure hose from the reference tap on side A to the interior of the dwelling This means that if you are in the garage the crawl space or in the attic you will need a pressure hose running under a door back to the interior of the house b Connect a red hose to the top tap on channel B The other end of this hose is connected to the duct blower flow ring 17 Pressurize the house with the blower door to the test pressure 25 Pascals Leave the blower door fan running 18 Make sure the digital pressure gauge is set on channel A 19 Set up the digital gauge properly a Turn the mode selection knob to time select and select 1 second North Dakota We
11. ore continuing 26 When the duct sealing and duct blower testing are completed shut down and remove the blower door and duct blower The final worst case draft test should be performed after the duct testing and duct sealing is completed 111000 Zone Pressure Diagnostics ZPD Testing 111010 Introduction Zone pressure diagnostics testing is performed to answer some fundamental questions where is the functioning air barrier and where should it be located These test procedures can also be used to measure the size of the leakage paths to various house zones Leaking air often takes a path that moves through two surfaces with a cavity or zone between These zones can include attics basements garages knee wall areas or attached porch roofs ZPD procedures require the measurement of pressure differences across air barriers like the pressure difference between the house and the zone attic for example while the house is depressurized by a blower door to 50 Pascals The procedures also require the determination of flows across air barriers These flows can be calculated with the steps of the ZPD procedures and a computer or North Dakota Weatherization Field Standards January 2003 Page 123
12. t if possible before and after converting the unconditioned space to a conditioned space ii Always repair disconnected ducts in the space iii It is preferred to seal the shell of the space rather than sealing the duct joints b If the unconditioned space is impossible to convert to a conditioned space or it is determined impractical to convert to a conditioned space i Use a duct blower to determine the duct leakage to the outdoors Examples of these types of unconditioned spaces include crawlspaces unconditioned basements attics attached or tuck under garages and exterior walls ii Repair seal with mastic and thermally insulate ducts in unconditioned spaces to at least an R 8 iii Goal Reduce duct leakage to the outdoors as measured with a duct blower and blower door to 10 percent of conditioned floor area 2 For ducts located in conditioned spaces such as a basement or crawlspace a Perform a house to zone pressure and flow test if conditions warrant to determine if the space in question is conditioned in terms of its shell air barrier The house to zone pressure should be 20 Pascals or less b Visually inspect the conditioned space to ensure that the shell is properly insulated c If it is determined that weatherization work should be done to the shell of the conditioned space housing the ducts perform a house to zone pressure and flow test if possible before and after the work to quantify the effecti
13. th Dakota Weatherization Field Standards January 2003 Page 119 a C Table 11 8 11000 Diagnostic Testing Procedures Make sure the pressure pan is properly connected to the manometer The proper connection should be reading the space under the pressure pan with reference to the main dwelling pressure Place the pressure pan completely over each register and grille in conditioned areas If a register or grille is larger than the pressure pan cover the oversized portion of the register or grille with tape while the reading is recorded If access to a register or grille is difficult for example at a kitchen counter kick space cover the entire opening with tape and insert the pressure probe through the tape near the center of the taped opening while the reading is recorded When two registers or grilles are closely connected to the same duct run for example two registers on opposite sides of the same partition wall seal one and use the pressure pan on the other unsealed register or grille Once you have taken the pressure pan reading remove the seal before proceeding to the next register Pressure Pan Multipliers 10 Record the pressure pan readings House Zone Pressure Pressure Pan before and after duct sealing Multiplier activities to get an idea of sealing 1 0 effectiveness It will sometimes be 1 useful to record readings during duct 125 sealing Always start your 1 66 measurements
14. using the blower 2 0 door as a reference point and work 2 5 clockwise around the dwelling a If an unconditioned space is not 10 0 well connected to the outdoors North Da e g unvented crawlspaces or unvented attics or has very large connections to the house then the unconditioned space will be at a pressure between the outside and inside house pressure during the blower door test In this case the pressure pan reading will show an artificially low number To correct this misleading number i With the dwelling at 50 Pascals measure the pressure difference between the main dwelling and the unconditioned space in question For example the house to zone pressure is 10 Pascals and the pressure pan reading is 2 0 Pascals ii Multiply the pressure pan reading by the multiplier in Table 11 8 to get the corrected and true reading For example multiply the pressure pan reading of 2 0 Pascals by the kota Weatherization Field Standards January 2003 Page 120 11000 Diagnostic Testing Procedures multiplier of 5 resulting in a pressure pan reading of 10 Pascals 11 If you are testing a house with a very leaky building shell and are not able to create a 50 Pa pressure difference with the blower door perform your pressure pan tests with the house at the highest achievable pressure In this case you will need to interpret your pressure pan readings carefully Compare the measured pressure p
15. veness of the work i Always repair disconnected ducts in the space ii Sealing the shell of the space rather than sealing the duct joints is preferred iii Goal The house to zone pressure should be 20 Pascals or less North Dakota Weatherization Field Standards January 2003 Page 118 11000 Diagnostic Testing Procedures 11930 Pressure Pan Testing Procedures 11931 Introduction Pressure pan testing helps find ductwork leaks or disconnections that are connected to outdoor air Testing before and after duct sealing gives an indication of the effectiveness of sealing efforts Pressure pans do not read duct leakage directly they infer leakage to the outdoors by reading the pressure at individual registers 11932 Test Procedure 1 Install the blower door for a depressurization test Make sure the dwelling is set up for winter conditions 2 Open all interior doors including the door to the basement if the basement is considered conditioned space heating system water heater washer or dryer located there and it is determined that the basement is part of the conditioned envelope 3 Make sure the furnace burner and air handler is off and will not start during the testing Remove the furnace filter and ensure that all registers grilles and balancing dampers are fully open a Exception When performing pressure pan testing in a mobile home block the filter opening by covering the filter with a plastic bag and reinsertin
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