Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
Ask a Question or Search InspectAPedia
InspectAPedia ® Home
ENERGY SAVINGS in buildings
ACOUSTICAL SEALANT CHOICES
AIR LEAK DETECTION TOOLS
AIR LEAK MINIMIZATION
AIR LEAK SEALING PROCEDURE
AIR SEALING STRATEGIES
ATTIC LEAKS, CONDENSATION & MOLD
BASEMENT CEILING VAPOR BARRIER
BASEMENT HEAT LOSS
BLOWER DOORS & AIR INFILTRATION
BRICK LINED WALLS
BRICK VENEER WALL AIR LEAKS
BUCKLED FOUNDATIONS due to INSULATION?
CATHEDRAL CEILING INSULATION
CATHEDRAL CEILING VENTILATION
CONDENSATION or SWEATING PIPES, TANKS
COOLING LOAD REDUCTION by ROOF VENTS
DEW POINT CALCULATION for WALLS
FRAMING DETAILS for BETTER INSULATION
FRAMING DETAILS for DOUBLE WALL HOUSES
FRAMING METAL STUD PERFORMANCE
FREEZE-PROOF A BUILDING
FROST HEAVES, FOUNDATION, SLAB
GREENHOUSE DESIGN for SOLAR HEATING
HEAT LOSS in BUILDINGS
HOT ROOF DESIGNS: Un-Vented Roof Solutions
HOUSEWRAP AIR & VAPOR BARRIERS
HUMIDITY LEVEL TARGET
INDOOR AIR QUALITY & HOUSE TIGHTNESS
INSULATION INSPECTION & IMPROVEMENT
INSULATION R-Values & Properties
LEED GREEN BUILDING CERTIFICATION
MOISTURE CONTROL in BUILDINGS
NOISE / SOUND DIAGNOSIS & CURE
ODORS & SMELLS DIAGNOSIS & CURE
SOUND CONTROL in buildings
STAIN DIAGNOSIS on BUILDING INTERIORS
THERMAL MASS in buildings
THERMAL TRACKING & HEAT LOSS
VAPOR BARRIERS & CONDENSATION in buildings
VENTILATION in BUILDINGS
WALL CONSTRUCTION BARRIER vs CAVITY
WIND WASHING INSULATION At EAVES
WINDOWS & DOORS
WINTERIZE A BUILDING
WOOD, COAL STOVES & FIREPLACES
WOOD STOVE SAFETY
Building heat loss troubleshooting & cures: beginning here, this article series discusses how to find points of heat loss and air leaks in existing buildings using a variety of tools and inspection methods including infra red, smoke tests, visual inspection, and tests. This article explains how to survey a building for air and heat loss or gain points and how to correct them. This article series discusses how to find points of heat loss and air leaks in existing buildings using a variety of tools and inspection methods including infra red, smoke tests, visual inspection, and tests. This detailed article accompanies a building weatherization and energy-savings company through a detailed building inspection for heat loss points and air leaks. The author accompanied Princeton Energy Partners as they used the blower door, thermal imaging, smoke guns, and visual inspection to pinpoint building air leaks, convective loops, heat loss points, air infiltration and air exfiltration on a building.
Green links show where you are. © Copyright 2013 InspectAPedia.com, All Rights Reserved. Author Daniel Friedman.
This article explains how to survey a building for air and heat loss or gain points and how to correct them.
The text below expands, paraphrases, quotes-from, updates, and comments an original article, "House Doctors with Better Medicine" - Steven Bliss, from Solar Age Magazine. Our photo (left) illustrates a step in a project by the website aurhtor (DF) and steps in sealing air leaks around a window in a New York Home.
The author accompanies a building weatherization and energy-savings company through a detailed building inspection for heat loss points and air leaks.
Princeton Energy Partners used the blower door, thermal imaging, smoke guns, and visual inspection to pinpoint building air leaks, convective loops, heat loss points, air infiltration and air exfiltration on a building. The energy sleuth team investigated a ca 1900 home in Swarthmore, Pennsylvania, with the goal of saving the client the most energy dollars possible based on a day's work of building investigation for air leaks, convective loops, and other energy loss points.
The energy-savings crew uses three principal tools: a blower door, an infrared scanner, and a smoke gun. Bit visual inspection also plays a critical role in testing the air leakiness of a building and in setting priorities for sealing air leaks.
The importance of setting priorities for sealing these points of energy wasted is emphasized and discussed, and sketches as well as photographs of common points of building heat loss, or unwanted heat gain, and air leaks are provided. Also see HEAT LOSS PREVENTION PRIORITIES.
House Air Change Rate per Hour Before Sealing Air Leaks
For the home studied in this article, the house leaked at 32 air changes per hour (ach) at 50 pascals of pressure. (We need to use a standard pressurization in order to compare leakage rates among homes or within the same home under different conditions such as before and after sealing.) Just how leaky is that? New energy efficient houses have natural air infiltration rates of 0.2 to 0.5 air changes per hour (ACH). So this 1900's home in Pennsylvania starts with an air leakage rate that is 64 to 160 times as leaky as a new, tight, energy-efficient home.
House Air Change Rate per Hour After Sealing Air Leaks
After sealing the leaks discussed below and before addressing leaky windows - often the major energy loss on older homes - the air changes per hour was reduced from the starting 32 ach down to 24 ach - a 25 percent improvement, for very little materials or labor cost. The crew pointed out that the sealing operations described below were more for comfort than energy savings, reducing drafts, eliminating cold spots in the home.
Following the discussion of building convective air loops, air leaks, & heating leaks below, we discuss the priorities of action in saving home heating or cooling energy costs
The importance of setting priorities for sealing these points of energy wasted is emphasized and discussed, and sketches as well as photographs of common points of building heat loss, or unwanted heat gain, and air leaks are provided. Accompanying text and sketches are reprinted/adapted/excerpted with permission from Solar Age Magazine - editor Steven Bliss.
As we introduced above, in this article the author, Steven Bliss, accompanies a building weatherization and energy-savings company through a detailed building inspection for heat loss points, convective loops, and air leaks. The author accompanies Princeton Energy Partners as they use thermal imaging, smoke guns, and visual inspection to pinpoint building air leaks, heat loss points, air infiltration and air exfiltration on a building. The importance of setting priorities for sealing these points of energy wasted is emphasized and discussed, and sketches as well as photographs of common points of building heat loss, or unwanted heat gain, and air leaks are provided.
The text below expands, paraphrases, quotes-from, updates, and comments an original article, "House Doctors with Better Medicine, Princeton Energy Partners use the latest diagnostic tools to comb a house for the major causes of heat loss. Their findings are often astonishing. Their strong prescriptions bring results", Steven Bliss, (see links just above) from Solar Age Magazine and written by Steven Bliss. Discussed here are these building heat loss investigation topics:
Attic Energy Loss Detected by Visual Inspection & Infra Red Scan Identifies Major Air Leaks in a Home's Attic
Where air leaks occur around fiberglass batts, look closely: you will probably see that the leaks are at the perimeter of the insulation and at locations where openings in framing, drywall, or insulation were cut to admit recessed ceiling lights, electrical or plumbing penetrations, or similar openings. If airflow were simply through the fiberglass batt in any uniform way, the dust stains on and inside the insulation would also be expected to be uniform. They are not.
We full agree with PEP, however, that predicting air leaks through fiberglass-insulated cavities is very difficult, since leakage depends on the quality of installation workmanship. We have indeed occasionally found workmanship errors that resulted in unanticipated air leaks though foam-sprayed insulation as well, particularly when the insulation (of either type) was installed in a hard-to-access space such as a crawl area.
Our pair of photos above were taken in a tight, hard to enter crawl area where the icynene spray foam insulation was not so carefully applied. Our smoke test found air movement from the damp, occasionally moldy crawl area into an opening in the foam insulating blanket. We pulled a bit of this already-leaky material off to see what was behind and found (photo above right) a leaky metal return air duct. When the air handler was running it was drawing cold, sometimes nasty, crawl space air into the duct system through this leak.
Estimating convective loop heat losses
In addition to their effect on energy bills, the impact of convective loops in buildings can be gauged by measuring attic temperatures before and after sealing off thermal bypasses such as chases and wall partitions, or it can be roughly modeled from the temperature difference and the height of the convective loop.
Stacked Bathrooms & Plumbing Chases Form Convective Loops
Energy retrofitting reduces drafts and cold spots and, according to PEP, produces some unanticipated benefits such as fewer rodent problems and fewer frozen pipes. Still, to sell the service to big buyers - the developers, housing authorities, and government agencies - it has to show an attractive return on investment. Says Gadsby referring to conventional weathersealing treatments, "To do a job for $1200. that's going to save $50. a year is just not the way to do business."In some cases the savings have been spectacular. For example in a 1982 retrofit, PEP spent three months retrofitting the 450-unit Glenhardie Condominium Comlex near Valley Forge, PA, for $62,000.
The 20-building development already had its insulation and heating system upgraded when it went condo four years earlier. After three months of house-doctoring, consisting solely of attic work, the annual heating bill was reduced from2093 to 1329 therms of natural gas, resulting in a first-year savings of $40,600, not including the $9,300. tax credit
.More typical was a proposal to the Baltimore Housing Authority, in which PEP agreed to treat apartments for $550. each while they were undergoing rehab. PEP's work was to be staged over two to three visits. With annual heating bills in that housing stock running $1200 to $1300 (1984 costs), the simple payback would be under three years. In terms of air infiltration alone, said Gadsby, recently-built townhouses generally measure in at about 10 to 15 ach (1984 data) at 50 Pascals before house-doctoring and are sealed down to about 6 ach after.
Costs for weatherizing are held down by providing the service in a one-day blitz, or in new construction in a series of quick hits. In general, a weatherization company can do more effective work for less money during construction or rehab than with retrofitting, since the problems are more visible and accessible.
The cost to the homeowner was estimated to be one half to two-thirds what it would cost to retrofit after construction, and you're probably going to save an extra 5 to 10 percent on energy costs as well.Here we include solar energy, solar heating, solar hot water, and related building energy efficiency improvement articles reprinted/adapted/excerpted with permission from Solar Age Magazine - editor Steven Bliss.
This article continues at BASEMENT HEAT LOSS DETECTION
Also see BTU Monitoring & HEATING COST APPORTIONMENT Issues where we discuss BTU usage monitoring & heating cost apportionment methods used in buildings housing multiple rental apartments or other tenants served by a single heating system.
Frequently Asked Questions (FAQs) about how to track down areas of heat loss in buildings
Questions & answers or comments about how to track down and fix points of buildng heat loss.
Ask a Question or Enter Search Terms in the InspectApedia search box just below.
Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.