2007 National Weatherization Training Conference Orlando Florida This

2007 National Weatherization Training Conference Orlando, Florida This Old House (of Pressure) Diagnosing Zone Pressures David Keefe, Anthony Cox, Wednesday, December 12, 2007 (8: 15 am to 9: 45 am) 1

Objectives • Understand the principles of zone pressure diagnostics • Learn how to interpret results • Locate existing air barriers; and • Determine the most effective air-sealing strategies. 2

Use Your Blower Door to do more – Where the air barrier (PRESSURE BOUNDARY) is so we can determine where to air seal – If the Pressure Boundary and insulation (THERMAL BOUNDARY) line up – Are zones with poor air quality such as Garages connected to the indoors – Is warm moist air getting into the cold Attic 3

Zone Testing • “Pressure Diagnostics” = Zone Testing • What are Zones? • Spaces that might be better connected to Inside or Outside 4

ZONE TYPES can you tell what determines type? Primary Zones Secondary Zones Attic Cantilevers Basement Floor Cavity b/w Floors Garage Soffits Crawlspace Porch Ceiling Attached Porch Interior Wall 5

Zone Types • Primary Zones – Are zones that have an opening in one of the surfaces • House to Zone or Zone to Outside • This is an advantage for testing • Secondary Zones – Do not have an access in either surface • Only Direct Pressure measurements can be taken 6

Levels of Zone Testing • Level 1 – Direct Pressure Measurement • Level 2 – Charts and Graphs • Level 3 – ZPD Calculators 7

Level 1 Pressure Only • Is the zone more indoors or more outdoors? • Do Pressure and Thermal Boundaries line up? 8

• The Pressure Boundary and Thermal Boundary must be together and continuous. 9

• If the boundaries are misaligned or If there are holes, voids or gaps this will make the building difficult to heat and cool. 10

11

Outside Zones and Inside Zones Measured with Reference to House We want Zones Outside the House (Unheated Areas) to be closer to 50 We want Zones Inside the House (Heated Areas) be closer to 0 12

Examples of Outside & Inside Zones Outside Zones (Unheated) q. Attics q. Garage q. Porches q. Crawlspace q. Basement Inside Zones (Heated) q. Interior Walls q. Floors Between Stories q. Crawlspace q. Basement 13

WRT With Reference To • Zone WRT House = 40 PA • Zone WRT Outside = ___PA • Zone WRT House = 15 PA • Zone WRT Outside = ___PA • Zone WRT House = 25 PA • Zone WRT Outside _______PA 14

Let’s Do Some Level 1! 15

16

17

18

19

20

21

22

23

Soffit Open to Attic 24

25

26

Kitchen Soffit and Base Cabinet were open to attic 27

28

29

30

31

Kneewall Attic Heated Area Insulated/Air Sealed 32

Kneewall Attic Unheated Area Insulated/Air Sealed 33

Kneewall Attic Unsealed/Uninsulated 34

Interconnection • Depressurize house to 50 Pa • Measure pressure to one zone • Open a door to the other zone, readjust blower door to read 50 again • If the zones are connected, the pressure in the first zone will change, If not, it won’t 35

Pressures and Leakage Attic Zonal Reading of 25 pa Means hole between Attic and House is Same size as Hole Between Attic and Outdoors 36

Pressures and Leakage Attic Zonal Reading of 48 pa Means hole between Attic and House is 1/8 th size of Hole Between Attic and Outdoors 37

Ratios of Pressures to Leakage Zone Pressures Relative Size of Leaks 38

Level 2 Charts and Graphs – Zone with an opening – Can calculate square inches leakage of both barriers – Can calculate the leakage through the zone (available CFM 50 reduction) Total Path Leakage 39

Total Path Leakage • The CFM 50 that describes how much air will go through the two barriers • Always less than the tightest barrier • Identifies potential for reduction in house CFM 50 40

Add a Hole • Depressurize house to 50 Pa, measure housezone and zone-out • Make a hole in one of the barriers • Adjust fan to keep 50 Pa, measure pressures • Use Chart or software to get CFM 50 of either barrier 41

Open a Door (Flow Method) • Depressurize house to 50 Pa, measure house CFM 50, house-zone and/or zone-out • Open a door with highest pressure difference across it (tightest air barrier) • Measure new house CFM 50 – Verify house-zone is near 0 and or zone-out 50 42

New Charts for In-Field • Garage Chart – You can always open a DOOR H/G or G/O (makes this easier) • Attic Chart – You can only open the hatch that is there (a bit more tricky) 43

Let’s Do Some Level 2! 44

Give the Charts a Try! (Hand them out!) • Attached garages – Quick – Easy – Important • Attics – Sometimes Quick and Easy – Also Important 45

Level 3 Software – More Detailed calculations using Software or Handheld Calculator – Test Can be automated with laptop computer and equipment 46

Remeasure When You Think You’re Done • Outside zones (attic, garage) should be much closer to 50 than when you started • Inside zones (interior walls, chases, ducts) should be much closer to zero than when you started • Zones that haven’t changed much in the right direction are opportunities for further improvement 47

Limitations/Cautions • Don’t attribute much meaning to measurements between 47 & 50 – Small errors in measuring may generate large errors in the result – Don’t assume attic is OK because pressure is 48 – Can seal zone-exterior (attic vents) to get numbers into a better range – Read small pressure 48

Limitations/Cautions • Re-check unusual measurements – – “If a number is unbelievable, don’t believe it!” Disconnected, misplaced or pinched hoses Unknown fans Mis-read gauges • Its best to be able to get 50 Pascal before and after adding a hole • Zone Connections can give exaggerated numbers in doing advanced on several zones, especially kneewalls 49

Improving Accuracy • Take Baseline Measurements • Measure pressures directly; don’t subtract • Try to measure the smallest pressure difference carefully • Do it again • For add-a-hole, try to add the hole to the barrier with the largest pressure difference 50

The End 51

52

Are the zones where they are supposed to be? ? If not we need to seal holes between inside and outside. By sealing the holes we stop Air Leakage by making a PRESSURE BOUNDARY Pressure Boundary (Air Block between Inside and Outside) 53

Porch is Open to Upstairs and Downstairs Exterior Walls Porch is open to Floor System between 1 st and 2 nd Floors (Can Look all the way through to Attic above single story) 57

58

Test Key Areas Ø Ø Attics, Side attics, Porch roofs Garages, Basements, Crawlspaces Chases (plumb, elec, duct, chimney) Plumbing Access, Duct Location, Soffits Keep It Simple Ø Record basic pressure measurements Ø Explain bad pressure readings (ex 10 attic) Ø Should take very little time (Bdoor is all ready up) 59

Kneewall Attic Unsealed/Uninsulated 60

61

Kneewall Attic Air Sealed/Uninsulated 62

Kneewall Attic Air Sealed/Insulated 63

Snow melting because of bypasses in attic kneewall 64

Interconnection • Depressurize house to 50 Pa • Measure pressure to one zone • Open a door to the other zone, readjust blower door to read 50 again • If the zones are connected, the pressure in the first zone will change, If not, it won’t 65

Ratios of Pressures to Leakage Zone Pressures Relative Size of Leaks 66

Attic Zone – Leakage paths and Surfaces Gable Roof Bypasses Ceiling Soffit

ATTICS • In Mild to Southern Climates (e. g. No Ice Damns) Direct Pressure is sufficient. • Look at venting to help guide you. – 48 PA WRT House and not a lot of venting = good, but if 48 and lot of venting still should check – 15 PA = there are some major holes that need to be dealt with 68

Attached Garage Zone Ceiling Exterior Garage Walls Garage Wall to House 69

Garage • Advanced Zonal Pressure Diagnostics are recommended – Open Door Method (Manual or with TI-86) – Hybrid Method (with ZPD Utility, PC, PDA, TI-86) • Ideal to get below 20 sq inches of Leakage between Garage and House 70

Basic Procedure • Measure pressure between the house and a zone, with the house depressurized to 50 Pa – Can close attic vents to get better numbers – Make sure to take baseline pressures – Is this zone in or out? A little or a lot? • Quantify the leakage – Add a hole – Open a door – Estimate venting 71

Add a Hole • Depressurize house to 50 Pa, measure housezone and zone-out • Make a hole in one of the barriers • Adjust fan to keep 50 Pa, measure pressures • Use chart or software (TI-86) WX Ware) to get CFM 50 of either barrier 72

Open hole to zone enough to reach target pressure while keeping Blower Door at 50 PA Measure Size of Hole made in Square Inches 74

Open a Door • Depressurize house to 50 Pa, measure house CFM 50, house-zone and/or zone-out • Open a door with highest pressure difference across it (tightest air barrier) • Measure new house CFM 50 – Verify house-zone is near 0 and or zone-out 50 76

Estimate Roof Venting • With house at 50 Pa, measure house-zone and zone-out • Estimate net free area of roof venting by visual inspection • Use chart or software to get house-zone CFM 50 • Usually the least accurate method, because difficult to estimate net free area 79

Add a Hole, Low-Tech Version • With house at 50, measure house-zone • Open a hole (attic hatch) just big enough to cut the house-zone pressure in half – Keep house at 50 • The hole you added is roughly equal to the existing leakage 81

Remeasure When You Think You’re Done • Outside zones (attic, garage) should be much closer to 50 than when you started • Inside zones (interior walls, chases, ducts) should be much closer to zero than when you started • Zones that haven’t changed much in the right direction are opportunities for further improvement 82

Limitations/Cautions • Don’t attribute much meaning to measurements between 47 & 50 – Small errors in measuring may generate large errors in the result – Don’t assume attic is OK because pressure is 48 – Can seal zone-exterior (attic vents) to get numbers into a better range – Read small pressure 83

Improving Accuracy • Measure pressures directly; don’t subtract • Try to measure the smallest pressure difference carefully • Do it again • For add-a-hole, try to add the hole to the barrier with the largest pressure difference 85

New Zone Pressure Diagnostics • Study Completed by Center for Energy and Environment, Michael Blasnik & Assoc. and the Energy Conservatory • To test out how accurate the current tests are and when to use them • Actually ended up creating a Hybrid method by combining Add a hole and Flow Method. To crosscheck and increase repeatability 86

When to Do Advanced Zonal Pressure Diagnostic Testing • Important to access amount of leakage for – IAQ issues (How much Leakage between Garage, or Moldy crawlspace and house) – Durability Issues (How much leakage of moist house air leaking into attic of cold climate house) 87

New Zone Diagnostics • Previously had programmed new hybrid method into a spreadsheet, and has now develop into a stand alone windows program, and currently developing for palm by The Energy Conservatory • Rick Karg has added this to the TI-86 Calculator (Ziptest Pro 2) 88

ZPD Utility for PC • Available at www. energyconservatory. com • Select Products link then click on Software • Scroll to bottom of page to download installation file 89

• ZPD Study Available at Energy Center of Wisconsin website www. ecw. org • To get directly to download page visit http: //www. ecw. org/ecw/productdetail. jsp? product. Id=384 90

Reference Articles • Home Energy Magazine May/June 2002 – Zone Pressure Diagnostics • Home Energy Magazine Sept/Oct 1994 – User Friendly Pressure Diagnostics – BOTH OF THESE ARE AVAILABLE AT www. homeenergy. org 91

TECTITE & ZPD Utility • The ZPD Utility can be used with a handheld manometer or by using TECTITE. • I use a form to collect data from TECTITE • Then am able quickly input data into ZPD Utility • TECTITE zone pressure info can be collected at same time as multi-point blower door test. 92

Summary of Work Flow (1) • Find Primary Zones and Thermal Boundaries • Infrared scan before Blower Door • Initial Blower Door Reading • Use Infrared Camera with Blower Door to locate air leakage paths 93

Summary of Work Flow (2) • Direct ZPD for all Primary Zones • Can use Pressure Ratio Chart to determine relative leakiness by estimating Net Free Area of Hole through one surface • Direct Measurement on suspicious areas – Cantilevers, Soffits, Chases, Floor Cavities, Porches • Check for Interconnections between zones 94

Summary of Work Flow (3) • Advanced ZPD for all Attached Garages and Crawlspaces with moisture/mold issues. • Advanced ZPD for Attics in cold climate areas, especially for tight houses with high moisture • Use Visual Clues and Smoke Puffer from inside zone to help locate leaks in Pressure Boundary 95

Summary of Work Flow (4) • Where is Pressure Boundary, – Is the Zone Inside or Outside • Does it line up with Thermal Boundary • Where should the Zone be and how will it be accomplished (Strategies for Air Sealing and Insulating) • Explain recommendations to client (Mechanical, Air sealing, and Insulation) – (e. g. leaving enclosed porch outside and insulating wall between the house and the porch) 96

Summary of Work Flow (5) Do Intermediate Blower Door Test • Did Zone Pressures move toward right direction – Exterior Zone closer to 50 PA WRT House – Interior Zone closer to 0 PA WRT House – Pressure Pans in outside zone less than 1. 0 PA 97

Summary of Work Flow (6) • Advanced ZPD to Measure remaining leakage to primary zones that were measured during the assessment • Final Infrared Scan • Take Final Blower Door Reading 98