Archive for the ‘Energy Audits’ Category

What is my house doing to me?

November 22, 2016

Fall River, MA

hhe-kitchen-hazards“Why do I wake up in the morning with a headache?”  “Why is the house so dry in the winter?”  “What are VOCs?”  “Does my house have a radon problem?”  Can you answer all these questions?  When we do an energy audit on a home, we are looking for issues that impact the heating and cooling loads.  But the same tools that we use for thermal analysis can be used to highlight unhealthy or hazardous conditions in a house.  The BPI Healthy Home Evaluator (HHE) certification merges energy efficiency and home health together.

On Tuesday the 15th and Wednesday the 16th of November, a first in the nation BPI HHE class was held at Bristol Community College.  The BPI credential was developed in partnership with the Green & Healthy Homes Initiative.  “It builds upon the BPI Building Analyst (BA), Energy Auditor (EA), and/orbpi-logo-4c Quality Control Inspector (QCI) certifications to verify competencies required to conduct in-depth healthy home environmental risk assessments.  The Healthy Home Evaluator assesses home-based environmental health and safety hazards and provides a prioritized list of recommendations to address those hazards.”

The two day class extensively reviewed numerous aspects of HHE skills including the liability issues involved in stepping into a hazards and health analysis, resident interviews, the identification and interpretation of hazards, and the seven “Keep Its” developed to clarify the primary elements of the program:

Keep it:

  1. Dry
  2. Clean
  3. Safe
  4. Ventilated
  5. Pest-free
  6. Contaminant-free
  7. Maintained

The class was able to apply these techniques to the test cabin located in the BCC weatherization laboratory while going through a typical field analysis incgas-leaksluding gas leak detection, CO monitoring, combustion safety testing, blower door testing, and ventilation system verification.  Added to these was asbestos pipe insulation, messy counters including cigarettes and spilled coffee, long blind cords, children’s toys in the oven, toxic chemicals in a cabinet, and a hazardous carpet.  These hazards were so common and obvious that the students missed many of them despite the fact that they had been sensitized to seeking them out.  Like odor fatigue, elements such as these are so common in an energy audit that they are simply overlooked.

What are the Lower Explosive Limits for natural gas, propane, and gasoline?  What is the impact on house pressures of a blocked return air vent?  Is it a water stain on the ceiling or sign of a mouse nest in the attic?  There are dozens of questions about a house.  Some of them are no problem at all.  Some of them are chronic, long term problems, and some of the are acute problems (like CO) that should be addressed immediately.

This is an evaluation credential.  There is so much to know about this stuff that it will take years of testing and experience to know the ins and outs.  But if we can get homes safer and healthier it will save a great deal on medical care which should appeal to health insurance companies and all of us.

If you wanbristol-community-college-1t to learn more about this stuff, Bristol Community College will be conducting more of these classes at 1082 Davol Street, Fall River, MA 02720 – 774-357-3644

Which version of CAZ testing is used for BPI/QCI testing?

April 20, 2015


Combustion Safety Testing is one of the most important components of the HEP QCI exam.  Because it is linked to the safety of the occupants, it has been a fundamental element of BPI exams since the inception of the organization.  As we make homes tighter and more energy efficient, we cut back on the supply of combustion air which can cause appliances to malfunction.  Since traditionally the combustion appliances rely on the buoyancy of warm air to function, as appliances get more efficient, their smaller chimneys and flues take less back pressure to fail.  More efficient systems use fans or blowers to force the air up the flue and out of the house, but it is the older, naturally drafted appliances (Category I gas appliances) that fail.  Testing has to be done to be sure that won’t happen under any circumstance.
There are a number of combustion testing protocols for the combustion appliance zone or CAZ.  BPI has been refining their standard for a number of years now.  If you are going to get Home Energy Professional (HEP) QCI certification, you want to be sure that both you and your proctor and working from the same standard.  Although the BPI 1200 Standard is now used for Building Analyst, Envelope, Heating, and AC & Heat Pump certifications, the HEP certifications still use the Building Analyst Professional Standard.  It would be a good idea to make sure that your proctor knows that before you start the testing.

Go to the BPI web site ( and download the Building Analyst Field Guide.

Take that and turn it in to a logical, sequential list.  Since the field exam is open book, you can refer to this and check it off as you go along.  Now, as an experienced auditor or building science professional, you may feel like you don’t need to check it off.  You’ve done it a thousand times!  Well, consider a pilot.  They may have flown that plane a thousand times, but I for one, hope that they never skip items on their checklist!  If you leave anything out and it cause you to fail, you will regret it.  Oh, and make sure when you are finished, you go back over the list and put things back the way they were.  You don’t want to be fifty miles away and get a call from the homeowner about not having any hot water!

When you assemble your CAZ checklist, make sure that you combine other elements of the HEP QCI Field Guide.  For example checking the chimneys to be sure that they comply with the 10:2 rule (chimney terminates two feet higher than anything in a ten foot radius)  and have a 1/4″ slope rise per foot of run. All that stuff should be on your checklist.

During the field test you want to be efficient and you want to talk all the time, telling your proctor what you are doing and why you are doing it, explaining everything.  But don’t look for confirmation.  If you say, “I’m putting my manometer probe in this hole I made in the flue.  Right?” the proctor should not give you any indication of whether you have completed the task successfully.  The proctor and his/her camera should be mute and effectively invisible.

This may sound basic, but make sure that the appliances in the test house will fire when you want them to!  Some water heaters may be full of hot water and turning the thermostat up won’t get them to fire.  You may have to run the hot water.  (I have had candidates under the pressure of testing, fling on the cold water tap and wonder why nothing is happening!  Testing does weird stuff sometimes.)

Also make sure you are familiar with your tools – particularly if you are borrowing them.  You want to know how to turn them on and set them up to take the readings that you need.  You want to make sure that the batteries aren’t dead.  Some combustible gas leak detectors and other tools time out after a while, for example.  You don’t want to be running downstairs and outside to restart the tool in the middle of the test.  (This is true whether it is for a certification test or just a regular, run-of-the-mill audit!)

Just to be allowed to take the HEP QCI exam means that you have a lot of experience.  You’ve done most of these tasks hundreds of times.  But it may have been a while since you did your initial BPI training.  Be sure you take advantage of all the resources available to you and don’t take the testing too casually.

If you are planning to challenge the BPI Quality Control Inspector’s certification, you might find the Quality Control Inspector’s Residential Handbook helpful.  Scheduled for publication on June 1, 2015.  For updates and a discount on publication, please add your name and email address by clicking on the book below.

QCI Handbook Cover copy

Visit us at

What does it take to be a certified Home Energy Professional Quality Control Inspector (HEP QCI)?

April 13, 2015

A quality control program requires knowing a lot about a lot of different subjects.  A HEP (BPI Home Energy Professional) Quality Into the Crawl SpaceControl Inspector is qualified to compare a project outcome to the project requirements or work scope so that the final result is satisfactory to both the program and the homeowner.  It requires both technical knowledge as well as “soft skills” which are difficult to teach, learn, and test.

Receiving QCI Certification is a major commitment of time and money and not a task to be entered into lightly.  You must be technically competent and experienced and you must be convinced that the commitment will be worth the reward.  As of January 1, 2015 the DOE Weatherization Assistance Program (WAP) requires program grantees to meet their Quality Work Plan.

The Weatherization Assistance Program’s (WAP) comprehensive Quality Work Plan establishes a benchmark for quality home energy upgrades. The plan includes an inspection and monitoring requirement that all WAP Grantees must meet.  All units reported to DOE as completed will be inspected to ensure compliance with the specifications in the SWS (Standard Work Specifications).  All quality control inspections, including monitoring inspections, must be conducted and signed-off by a certified Home Energy Professional Quality Control Inspector.

There are about twenty-five Weatherization Assistance Agencies throughout the U.S. and there are about sixteen regional weatherization assistance training programs.  (These numbers come from the WAPTAC website

Most of the QCI inspections are likely to be performed by internal staff at the weatherization agencies and programs.  It is expensive for an independent contractor to carry the necessary liability insurance, although many independent energy efficiency contractors are already carrying a heavy insurance load for audits and HERS ratings.

The HEP QCI certification is a BPI (Building Performance Institute ) certification program.  In order to be qualified to challenge the required exams, there are a number of experience requirements as defined on the BPI HEP prerequisite page.  One of the biggest challenges is being able to prove the experience related credentials.  It is important that anyone thinking of achieving these credentials begin to log or document their experience.  This might require going back to former employers to get them to sign off.   Experiences are summarized by adding up a minimum of forty points from five different areas:

1)    Industry inspector experience;
2)    Other industry experience;
3)    Building experience;
4)    Training;
5)    Industry certification

Inspector experience can include site visits, inspections, and diagnostics for a maximum of twenty points, defined as ten points for every one thousand hours of experience.  If an average energy audit takes you two hours, it would require five hundred audits for ten points.

If you were an energy auditor or crew leader, you could include five points for crew leader and ten points for energy auditor as long as you have completed a minimum of fifteen documented audits.  You will need to have an organization attest to the fact that you have completed two thousand hours as a crew leader and/or two thousand hours as an energy auditor and completed fifteen audits.

For building experience such as framing, roofing, drywalling, or siding you could include a maximum of ten points with five points allocated to every one thousand hours.  You will need to have an organization verify that you have completed one thousand hours of building experience for each five points.

You can include a maximum of ten points for eighty hours of training (five points per forty hours).

Finally you can list five points per industry certification (with a maximum of ten points) for RESNET, BPI, NATE, or EPA.  Other industry related certifications are also considered.

Once you have applied and your experience verified and you have been approved to take the exams, you will have two and half hours for the written exam at a cost of approximately $250 (depending on the testing organization) and three and a half hours at a cost of approximately $700 to take the field exam.   (Reportedly the field exam can be accomplished in less time if the house is relatively basic.)

The HEP QCI certification is valid for three years.

There are twenty-nine organizations that offer QCI training (according to the BPI website).  The first thing to look for is a training provider that is IREC (Interstate Renewable Energy Council) Accredited.  An organization that has achieved IREC Accreditation has gone through an extensive review of all of its practices and programs from the content of the courses to the solidity of its economics.  An experienced IREC assessor has reviewed it all: everything that a student would want to know.

There are fourteen organizations in the U.S. whose HEP QCI courses have been accredited.  Go to the IREC website for their locations.   This is not to say that the other training programs are not good.  They may be excellent but seeing the IREC Accreditation gives you one more level of assurance – quality assurance – in the program.  And if you’re going to invest that kind of money, you should use the best.  It may not necessarily be the closest – and there is something to be said for limited travel costs – but you’re making an investment so it should be a good one.

The QCI course is based on a Job Task Analysis or JTA developed by a team of industry experts.  The QCI JTA consists of five knowledge domains:
Domain I: Conducting Quality Checks – In-Process Visual/Sensory Inspections
Domain II: Conducting Quality Checks – Post-work Visual/Sensory Inspection
Domain III: Conducting Quality Checks – Post Work Diagnostic Inspections
Domain IV: Ensuring Worker Professionalism
Domain V: Ensuring Program or Project Compliance

Each of these domains are broken down into four or five tasks.  BPI has a “Field Guide” on their website.  The Field Guide includes everything that is on the field test.  It would be reasonable to go through everything listed on the Field Guide and make sure that you know how to efficiently perform every task.  It would also be advisable to rewrite the field guide (including all the items) into a checklist in the order that you are familiar with.  (Note that you want to be sure to perform every step in the Field Guide.  Just because a task seems obvious or inconsequential or not applicable to the present home, doesn’t mean that you should ignore it.)  The BPI Field Guide is grouped in similar areas – all the items related to work problems in one area and all the items related to CO in another area.  Bouncing back and forth will be inefficient and time consuming.  It makes much more sense to reorganize the Guide in a logical and sequential list.  At the same time you will be familiarizing yourself with what is included and less likely to be fumbling around during the field test.

More on these  Domains and Tasks to come in future blog posts.


If you are planning to challenge the BPI Quality Control Inspector’s certification, you might find the Quality Control Inspector’s Residential Handbook helpful.  Scheduled for publication on June 1, 2015.  For updates and a discount on publication, please add your name and email address by clicking on the book below.

QCI Handbook Cover copy

Visit us at

Remembering Common Sense

March 23, 2015

A house is meant to be a shelter from the weather, a small, controlled subsection of the planet earth where a family can live safely and comfortably. Caves worked but they were hard to keep warm. But they mostly kept the rain off and blocked some of the wind. House design has advanced over the years becoming safer and more protective. Most of the time. There have been problems with chimneys, for example. A hole in the roof works to let some of the smoke out, but it was an improvement to enclose more of the smoke and guide more of it out. But there was a problem with wooden chimneys. Common sense dictated that chimneys be built of fireproof materials. In fact, many of the improvements in building science were dictated by common sense, wisdom, and skill. The problem came into it when unskilled builders decided that it couldn’t be all that hard and there was money to be made by ignoring some of the details. So rules and codes and standards were created.

Now there isn’t anything inherently wrong with having rules and codes and standards. The problem is that the focus tends to drift from why the rule or code or standard was created in the first place to developing rules and codes and standards just to regulate the rules and codes and standards. Let’s face it: we’re not perfect. And our rules and codes and standards won’t ever be universally perfect either no matter how hard we tweak and tinker and debate. Some people like a airconditioned thatchlittle more salt on their meat and some a little less. And some don’t like meat at all. One rule that covers all the ways to eat a steak simply wouldn’t work. We could have committees and conferences and technical papers ad nauseam but we would still never come up with the perfect rule. When a committee or a society or a club self-perpetuates by simply constantly making changes to a set of rules, the original point is lost. No doubt we are learning more and things change, but we’ve lost the link to common sense. There is no room in our rules or codes or standards for the application of common sense! And we need to just stop and try to remember why the rule or code or standard was written in the first place!

What is the fundamental, bottom line point for the existence of the ASHRAE 62 Standard, for example? (Having been on that committee for over ten years now, I feel that I have a right to use it as an example.) The Standard says, “This standard defines the roles and minimum requirements for mechanical and natural ventilation systems and the building envelope intended to provide acceptable indoor air quality (IAQ) in low-rise residential buildings.” That sounds pretty reasonable. The basics of the standard are great – segmented and detailed to define important stuff. Why can’t we just finish it? Maybe tweak it a little once in a while as we learn more and technology improves. But a huge amount of brain power and hours of discussion and tons of paper go into the constant adjustment of the standard.

When a 747 is landing, it is important for the pilot to line the plane up with the runway accurately so that that little or no adjustment is need to keep the plane rolling straight when it touches the ground. At those speeds, any moderately radical change of direction would be disastrous. A consensus standard is the result of general agreement about diverse views. Can you imagine what would happen if a 747 was landed by a committee? A compendium of diverse views doesn’t always allow room for common sense.

If you are planning to challenge the BPI Quality Control Inspector’s certification, you might find the Quality Control Inspector’s Residential Handbook helpful. Publishing date is June 1, 2015.  Add your name to stay in touch.  Thanks.

QCI Handbook Cover copy

KSAs – Teaching the ‘A’

March 16, 2015

What are KSAs?  Kosher Supervision of America?  Knights Saving Armadillos? In building science terms (and others) KSA is an acronym for Knowledge, Skills, and Abilities.  There is no question about the Knowledge part.  You definitely have to know what you are doing when you are working on a house.  You have to know about the concept of the “house as a system”.   You have to know how to do basic math.  You have to know what ACH and CFM mean.  That knowledge can be presented and learned.  You can read it in a text book or hear it from a trainer.

Attic soffit stuffing

KSAs in an attic

There is also no question about Skills.  You have to have the skill to operate a blower door or a combustion analyzer.  Once you know how to do it, you can develop the skill by continuing to do it.  Some people can play their manometers like Stradivarius violins.  That’s a skill.

And there really is no question about the requirement for Ability to get the job done.  The problem is that you can’t teach ‘ability’.  Ability is either there or it’s not.  No matter how much knowledge you have or skills you have learned, if you’re not able to do the job you can’t do the job.  It might be better, however, to consider that the ‘A’ stands for attitude.  Ability and attitude go hand in hand.  When someone says, “I can’t!”, does that really mean that they lack the ability to do the job?  Or is it that they lack the right attitude?  They don’t feel like doing the job or the task or the event?  You can’t teach attitude either.  Maybe it’s in the motivation.  Maybe it’s self confidence or desire or the reward for getting it done or the punishment for failing.

Imagine you are in a hot attic sealing duct work and you are there by yourself.  It’s the end of the day and you are tired.  It’s dirty and dusty and cramped and your legs hurt and your arms hurt and your head hurts from bumping it on the underside of the roof.  There is one last joint off there in a corner.  No one will ever know if you finish the job and seal that joint . . . no one but you.  You have the knowledge.  You have the skill.  And you have the ability.  But do you have the attitude?

A quality control inspector has to have the knowledge and skill and ability to read the crew members’ attitude.

If you are planning to challenge the BPI Quality Control Inspector’s certification, you might find the Quality Control Inspector’s Residential Handbook helpful.

QCI Handbook Cover copy

What’s Your Quality Control Mission Statement?

March 9, 2015

Even with the best intentions, mistakes get made.  The meaning of mistake is defined by your Mission Statement.  A Quality Control Inspector moves the result of a project one step closer to perfection.  To do that, the inspector has to be a generalist and understand all the aspects of the project and have the experience of making his or her own mistakes and have learned from them.  The weatherization of a home has many parts from an initial analysis to determine what needs to be done, to understanding the systemic nature of construction, to appreciating the needs and resources of the homeowner, to the capabilities of the crew performing the work, to the verification that the results match the initial expectations.

A Quality Control Inspector is a residential energy efficiency professional who ensures the completion, appropriateness, and quality of energy upgrade work by conducting a methodical audit/inspection of the building, performing safety and diagnostic tests, and observing the work.
Imagine that there is a small house owned by a nice old lady who is struggling to meet her bills and tolerating exceptionally cold 090831_1474conditions in the winter and excess heat in the summer, conditions that make her life miserable.  The house fits into the local weatherization program and a BPI (Building Performance Institute) certified energy auditor has visited the house and created a work order to make improvements.  He did a blower door test to measure the leakage, measured the insulation depth in the attic, determined the existing insulation in the walls, and tested the atmospherically vented combustion, gas fired water heater, furnace and oven for safety.  And the crew comes in and begins to work.
The weatherization crew consists of a certified Crew Leader and a good crew who perform consistently good work.  You are the quality control inspector on the job and during an in-progress inspection you find that the auditor mis-identified the building envelope and the installers are not insulating a wall between the conditioned and unconditioned space, a living-room and enclosed porch. They will complete wall insulation this afternoon, according to their schedule. If you stop the job, you will miss the completion time and extend the job.  If you don’t stop the job, will you be doing your job as the quality control inspector?

Life is full of compromises.  A compromise means that you give up something to accomplish something else.  It’s the greatest good for the greatest number kind of thing not the end justifies the means.  Someone on the crew needs to understand where the thermal envelope is and point it out to the Crew Leader.  Certainly, the Crew Leader should know.  The Leader should have pointed it out to the Energy Auditor because it was wrong on the work order.  The homeowner is the one who is going to lose out because she is completely unaware of the mechanics of the problem, although she may feel uncomfortable in that room.

As the Quality Control Inspector, you should be able to turn to your mission statement to answer this question.  If your mission statement is focused on cost effectiveness, then you have to weigh the cost impact of stopping the job.  If you mission statement puts the comfort of the homeowner first, then stop the job and do it right.  But you can’t know that you have achieved success if you haven’t defined what success means to begin with.

A mission statement defines the organization’s purpose and primary objectives.  If the mission statement says that your organization’s purpose is to provide the most energy efficient, comfortable, and safe homes to your clients, then there is no question about what should be done for this home





If you are planning to challenge the BPI Quality Control Inspector’s certification, you might find the Quality Control Inspector’s Residential Handbook helpful.

QCI Handbook Cover copy

If we’re going to do the job at all, we might as well do it right!

March 2, 2015

Gas ChecksDespite our best intentions, everybody makes mistakes.  It may be from lack of knowledge.  It may be from laziness.  It may be from just not paying attention.  Some mistakes have no consequences.  Some mistakes can kill people.  There are a lot of skills that go into making a house more energy efficient.  You can learn the fundamentals of the laws of thermodynamics and how to operate a blower door or an infrared camera, but the only way you gain wisdom is through experience.  When you are in  a crawl space sealing up the ducting joints and there is one more joint way back in the corner that no one will ever see except you  and it is damp and dirty and you’re lying on the floor covered with building rubble, are you going to go back there and get the job done?  Are you just going to work your way back out of there, shrug your shoulders, and justify it to yourself?  That’s what KSA means: Knowledge, Skills, and . . . Attitude.  Some people say it’s Knowledge, Skills, and Ability.  And you do have to have the ability to get the job done.  But you also need to have the right Attitude.

Quality Control Inspectors are the last line of defense.  They must have the right attitude.  The energy auditor checks out the house and creates the work order.  The crew comes in with the crew leader and gets the job done.  The quality control inspector makes sure that the ‘i’s‘ are dotted and the ‘t’s‘ are crossed and . . . that last connection in the crawl space is sealed.  Sometimes the QCI is called in because there is a problem like excessive humidity on the windows.  Sometimes is just a matter of signing off on the job.  If everyone did their jobs perfectly, QCIs wouldn’t be necessary.  And who’s going to check the QCI?d

The BPI Home Energy Professional (HEP) certifications take a lot of knowledge, skills, ability (attitude), and experience.  You have to prove that you know a lot about a lot of things.  To assist in that process, I am creating a Quality Control Inspectors Handbook.  The National Renewable Energy Laboratories (NREL) Job Task Analysis (JTA), what the certification is based on, covers a lot of fundamental and soft skills.  The book will go through all the Domains and Tasks in the JTA as well as all the elements that are included in the BPI field exam.  There is a need for more QCIs to meet the states’ Quality Work Plans.  My goal is to provide a resource that can support these efforts.  If we’re going to do the job at all, we might as well do it right!

If you would like to stay updated on the progress of the book, click on Keep Me Updated!  QCI Handbook Cover copyThank you.

BPI Building Analyst and Envelope Professional Problems

March 11, 2014


I just taught a BPI Introduction to Building Science course last week that included both the information required for both Building Analyst and Envelope Professional.  There is an enormous amount of complex information included particularly for someone who may never have been in an attic or framed a house.  It’s all new from the second law of thermodynamics to R value to convection and boilers.  We are asking them to take in and understand and retain all of that information which has likely been shoveled at them in a week-long course.

On top of that we are working off two different Standards.  There is some information that is in the Building Analyst Standard (17 pages long) and some information in the 1200 Standard (47 pages long) (which is still a draft).  I have serious doubts that many people will actually read the new standard and refer to Paragraph to determine an action level for spillage!

And even more confusing is that the trainers have not been informed as to what needs to be taught for the tests, or if the proctors are looking for different things than the trainers think they are training for.

The 1200 Standard has removed the need for “values” – actual numbers for CAZ depressurization and draft (if it’s higher than x it’s good, lower, it’s bad).  And in fact draft doesn’t even have to be measured.  The standard only indicates if it’s bad if it spills.  Yet we are now asking for CO Airfree on some things and not on others and not all test equipment displays CO Airfree so it has to be calculated.  And the 1200 Standard says “The draft table is provided by permission of the American Gas Association” although it is referring to a table that is in draft form not to a level of pressure.  It is hard to tell what an auditor is supposed to do besides telling the homeowner that their boiler or furnace needs servicing.  Do we really need to have auditors buy an expensive combustion analyzer for that one measurement, something they probably don’t understand and can’t do anything about?

And for gas leaks we need a device that actually measures LEL which is not what the Leakator (the common combustible gas leak detector) does now so it is another piece of equipment students will have to buy and proctors will have to have available.

There are various other discrepancies that make these confusing issues a challenge to teach.  on top of those there are the various categories: Building Analyst, Energy Auditor and Home Energy Professional.  I had students go to the BPI website per my suggestion, and they down-loaded different knowledge lists.

We need an Intro to Building Science Course that one could attend to get an introductory Building Analyst Certification, Building Analyst 1.  That should refer to a “Getting Started Standard” that combined the good parts of both the old Standard and the new 1200 Standard.  The Getting Started Standard should be no more than four pages long.  Maybe it should have a bunch of pictures like the instructions that come with a new computer.


I refuse to teach to a test.  I think the students should understand what they are learning and not just memorize numbers and hose positions.  But there should be a block of maybe twenty-five items that the beginning participants could be taught that would be clear and simple.  Do we really expect them to go to Section 7.8.5, ANSI/BSR Z223.1/NFPA 54, National Fuel Gas Code, Table G-6: CO Thresholds?

Please visit our website at

Building Diagnostics and Infrared Cameras

November 20, 2013

Infrared photography for thermal analysis has changed dramatically in the last thirty years.  The cost of the cameras has dropped to the point where just about anyone can buy one.  But that doesn’t mean that anyone can understand the information they are providing.  I know someone who uses his infrared camera to find his dog when he lets him out at night!

Most of the infrared cameras come with an adjustable palette.  When I am using the camera for diagnostics, I use the Door leaksblack and white palette because it allows me to quickly identify areas that are colder or hotter than they should be, places where air is leaking in.  These spots are amplified if I am running a blower door at the same time; the air is steaming in, streaking the wall with cold fingers.  That quickly tells me where the weather stripping or the air sealing should be improved.  Note that the difference in color is only a difference in temperature.  It may only be a small difference.  When an infrared camera is used for electronic or mechanical equipment diagnostic, the actual temperature is important.  In diagnosing a house, the difference in temperature not the actual temperature     is tAttic Hatchhe important element.

This image is an uninsulated attic hatch.  It is clear that the insulation level of hatch is different than the insulation level surrounding it.  But unless we look at the temperature scale and know the temperature of the attic, we don’t know if the hatch insulation is R1 or R30.  Looking at the temperature scale, the hottest point in this image (right around the edge of the hatch) is 75 degrees F and the coldest point on the ceiling is 68 degrees F.  The colors make it look much more extreme.  When you are using an infrared with a customer, the color palette is a great sales tool.  And people use them to sell all sorts of things that may or may not be there.

Attic StairsOr look at these attic stairs.  These stairs had cellulose insulation blown in around them and the temperatures are pretty even.  The temperature in the hottest spots (those little white areas at the corners of the steps) is 54.9 degrees F and temperature in the black areas is 46.3 degrees F.

I have tested ducts in houses where the sheetrockers sheetrocked right over the top of one of the supply registers.  The infrared camera made it easy to find when I cranked up the heat and that part of the wall glowed in an attractive, rectangular pattern!  Or if you are thinking of cutting into a wall, you may be able to see where the pipes are before you cut the wall (and the pipes) open.

Infrared cameras do not xray the wall.  They only show you surface temperature and the surface temperature can be changed by external elements particularly the sun.  One house I worked on had a window beside a slider.  The amount of solar gain passing through a window is rated as SHGC (Solar Heat Gain Coefficient).  The window had an SHGC of 0.32 and the door had an SHGC of 0.27.  The sun was pouring through the glass and warming the hardwood floor.  It was easy to see the difference in temperature  with the infrared.  I wouldn’t have known what the SHGC number was without the sticker on the glass, but I could certainly tell that they were different with the camera.

Infrared cameras are wondrous tools, but until you clearly understand them and know how to use them, the information they provide is interesting but not definitive.


Please visit our website for more building science information:

Test As We Work

August 1, 2013

Ad-SocratesWhen Socrates sat around with his students discussing the issues of the world, they didn’t have laptops or cell phones, piles of books or even papers.  If they did have tablets, they certainly didn’t look like they do today! The students really needed to pay attention and remember what was talked about.  Even later, stories and histories were passed on from person to person.  Carpenters, stone masons, cobblers passed along their skills by demonstrating their techniques.

Now students sit at desks or tables in classrooms and watch Power Point pictures, often covered with words.  They have to be able to read and understand sentence structure.  And then there is the testing.  I just finished teaching a class on heating and distribution systems.  One of the questions on one of the daily tests was:

Steady State Efficiency is measured with a digital gas analyzer in undiluted flue gases.  True or False. 

What is important here?  The students need to know what “Steady State Efficiency” is.  Steady State Efficiency is a measurement of the efficiency of the appliance when it has reached steady state combustion after about five minutes of operation.  It is a combination of the temperature of the flue gases relative to the temperature in the combustion appliance zone (CAZ) and the Oxygen in the flue gases.  That’s an important part of the process.  And they need to know how to measure it.  They also need to know where to measure it.  Do they measure it in “undiluted flue gases”?  That would mean that the flue gases were not diluted with extra oxygen.  So it would seem that the answer to the question should be “True”.

But whoever wrote the question snuck the word “gas” in there in front of analyzer.  There are a lot of tools that we use in the field – manometers, thermometers, anemometers, gas leak detectors, and combustion analyzers.  We call them different things – sniffers, Balometers, pressure gauges, and maybe gas analyzers.  If you know what tool to use, how critically important is it to have a precise lexicon of names?  Do we need another Standard to define names?  How critically important is it to use the same color hoses on your manometer for each test?  Would it be wrong to say: “The red hose should be connected to the Reference Tap on Channel A of the manometer in order to reference the outside.”?  Certainly not if you’re using a Retrotec manometer.  And in fact if you search for “gas” analyzer on Google, it will reference all sorts of combustion analyzers.

And that’s what this question essentially gets down to.  What the writer was looking for was an answer of “False” because it is not a gas analyzer it is a combustion analyzer.  I was so perplexed by this question that I sent it out to several people who teach and write this stuff every day and they both answered “True”.  So are we testing people on language or on the ability to get the job done?  Are these multiple choice exams really a good test of someone who spends the day crawling under the bellies of mobile homes or in the hot, dark recesses of attics to seal duct work?  Over and over again in these classes I hear the comment, “This class could be improved with more hands-on time.”  We really need to develop a better way to test and train and mentor, with a more comprehensive apprenticeship program.  It would be preferable for a proctor or mentor spend an extended time with a candidate and finally say, “Yes.  This person knows what they are doing.  I would let them test the systems in my house.  My wife and children would be safe living there when he or she had completed testing.”

Please visit us at