Pressure and Thermal Boundaries

Report
Overview
•
•
•
•
•
•
•
•
•
•
•
•
Introduction to the Weatherization Assistance Program
Communication Skills
House as a System
Building Science Basics
Blower Door Basics
Pressure and Thermal Boundaries
Combustion Safety
Worker Safety
Materials, Tools, & Equipment
Typical Weatherization Measures
Mobile Home Basics
Multifamily Basics
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
1
Learning Objectives
PRESSURE & THERMAL BOUNDARIES
By attending this session, participants will:
• Understand the difference between the thermal boundary
and the air or pressure boundary, and the behavior and
function of each
• Know the proper location of the pressure and
thermal boundaries
• Know common sites for breaks in the pressure and
thermal boundaries
• Understand what is meant by inside and outside in
terms of air barrier, and how a blower door is used to
determine that
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
2
Thermal & Air Barriers
PRESSURE & THERMAL BOUNDARIES
For maximum efficiency and comfort,
the thermal and air barriers must be
continuous and in contact with each other.
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
3
Thermal & Air Barriers
PRESSURE & THERMAL BOUNDARIES
An uninsulated attic
hatch is a gap in the
attic’s thermal barrier
Air Barrier
Thermal Barrier
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
4
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
5
PRESSURE & THERMAL BOUNDARIES
A mechanical chase
containing ducts can
break the attic’s
air barrier
Air Barrier
Thermal Barrier
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
6
Moisture
PRESSURE & THERMAL BOUNDARIES
Moisture flows with warm
air through breaks in the
air barrier, causing damage
when it condenses on
cool surfaces.
Air Barrier
Thermal Barrier
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
7
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
8
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
9
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
10
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
11
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
12
Blower Door Test
PRESSURE & THERMAL BOUNDARIES
ΔP = -50 Pa
Blower Door
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
13
Zone Pressure Diagnostics
PRESSURE & THERMAL BOUNDARIES
Pressure difference of
attic with reference to
the house should be
close to -50 Pa
ΔP = -50 Pa
Blower Door
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
14
Zone Pressure Diagnostics
PRESSURE & THERMAL BOUNDARIES
Pressure difference of
interior wall with reference
to the house should be
close to 0 Pa
ΔP = 0 Pa
Blower Door
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
15
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
16
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
17
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
18
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
19
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
20
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
21
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
22
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
23
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
24
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
25
Where Is the Air Barrier?
PRESSURE & THERMAL BOUNDARIES
Cape Cod
1½ Story House
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
26
Where Is the Air Barrier?
PRESSURE & THERMAL BOUNDARIES
Pressure difference of the
floor cavity with reference
to the house should be
0 Pa. But, is it?
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
27
Where Is the Air Barrier?
PRESSURE & THERMAL BOUNDARIES
Targeted air sealing
defines air barrier
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
28
Where Is the Air Barrier?
PRESSURE & THERMAL BOUNDARIES
Pressure and thermal
boundaries are
now aligned
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
29
Summary
PRESSURE & THERMAL BOUNDARIES
• For maximum efficiency and comfort, the thermal and
pressure boundaries must be continuous and in contact
with one another
• Electrical and mechanical chases, missing top plates,
knee walls and dropped ceilings are common trouble spots
• Pressure diagnostics determine location and condition
of air barrier
• Zonal pressure readings in conditioned spaces should read
close to 0 WRT inside
• Targeted air sealing defines the pressure boundary
WEATHERIZATION ASSISTANCE PROGRAM STANDARDIZED CURRICULUM
30

similar documents