InterNACHI releases "How to Perform Energy Audits" FREE online 3-day course.

Brian, aside from all the jargon, here is something that you have to realize, in our area. I have never seen a house (new or old) that had less than 15 ACH. No one, around here, air seals. A blower door is usually not needed. I just turn on the bathroom and stove vents and turn on the clothes dryer to air fluff and see many areas of infiltration. When there is no delta T (usually only for a month or two in spring and summer) I use a smoke pen and fogger. It does n’t take much to find air leaks when they are so many and when you are experienced with where to look, given the common building techniques in this area.

As I have stated, most customers don’t want an detailed, formal, quantitative audit. They want to know where the problems are, how to prioritize and fix them and where to find professionals who know how to fix them properly.

Also, many HVAC people around here are a joke and don’t know the proper way to install high efficiency furnaces (no combustion air intakes run). Doesn’t take a genius to call this out and save them 10% efficiency on the heating gas costs.

Hope this helps;

Check out David Valley’s blog over at Linked-In in regards to the use of blower doors.

I would particularly pay attention to the comments from:

L. Terry Clausing, P.E.
BPI Certified Building Analyst & Envelop Proctor/Instructor
ASNT Certified NDT Level III Thermal Infrared Thermography


Posted there. Thanks for the heads-up, Linus.

Don’t you just love it when P.E.'s speak down to us poor, lowly home inspectors? :mrgreen:

I don’t feel he was speaking down to anyone. His comments are on point!! Sorry Will, but your posts here and over at LinkedIn shows your ignorance on the subject of blower doors. On that thread you indicated that you have certifications from BPI and that you have done comparisons with/with-out the Blower Door per BPI Standards.

So, just to be clear…Are you a BPI Certified Building Analyst and do you own a Blower Door?


Can you take this course and then take the BPI exam without take the BPI course?

Yes, You need a few study guides and you’ll do fine.
Saturn Energy Auditor Field Guide
Residential Energy
Building Analyst Field Training Video

Why spend all your money on certification and be an out of work building analyst when you can do it for a few hundred $$$.


Linus is 100% correct on those resources, you will have a very good shot at passing the exam with those. However, you are required to do field audits, and that is where you can run in to issues. A lot of the field auditors/proctors for BPI are super swamped right now. They also know they can sometimes charge whatever they want to do your field exams. I have found it is just better to go through a certified BPI training facility that includes the BPI exam and field audits right in their training.

Training materials + exam fee + field audits could be a lot more than $1595 (average price through out the country). If you are in AZ there is a local company here that does it for $875 (Peter did his training there) and if you are an AZ business/resident APS will kick you back 50% of that.

Clean Edison is nationwide and a little birdy told me they will soon have a BPI/Resnet all in one class. Here is a link to all their current BPI offerings throughout the country.


Clean Edison will be at studios all next week. It’s all going online in HD through

Anyone who comments on blower doors that does not own one and use it daily clearly does not know what they’re talking about.


I went through the Energy Audit course (and passed the test, yay!). It is a good starter to doing energy audits, but not even close to being enough training to do an evaluation properly in my opinion. Auditors have to realize that being a good energy auditor goes way beyond a good training course. It takes countless hours of research on products and building science just to scratch the surface of the energy field. I have personally done over 500 energy evaluations, and consider myself very good at what I do, but I also realize that I still have alot to learn. I believe continuing education is extremely important in the energy field. You can spend hundreds of hours learning something, then only to find out there has been 10 new things that have been developed since you started. If there has been one main thing i have learned it is that just when you think you have learned it all…its time to start all over again! I guess thats why I love what I do. There, thats my 2 cents worth.

I thought I would add this. This is from I job I completed yesterday and here is what we did.
Replace weather stripping and sweeps on three doors
Treat attic hatch and insulate with 4’’ HI-R foam
Repair holes in bathroom walls, effected pressure
Air seal all penetrations in attic
Open blow cellulose insulation to R-45 1200 Sqr. FT
Dense pack side wall overhang, Garrison style home to 8’’ 325 SQR FT
Replace T-Stat with digital
Replace bathroom fan/light with Panasonic 110 CFM and hard pipe through the roof with insulation and new roof vent.
Replace rotted chimney clean out door
Replace rotted fascia and soffit, 11 Feet
Hard pipe dryer vent with new hood

Pre blower door test 1700 CFM@50
Post blower door test 1380 CFM@50
Conducted pre and post CAZ test
Conduct boiler efficiency test pre and post retrofit

Total cost of retrofit $3086.00
Energy audit with thermal imaging 500.00

Total cost of job 3586.00

All of this is pretty funny. Secretaries are now getting LEED designations, just by working for firms who do the designs, because with LEED, one needs to have participated in the design process.

Many governmental agencies do not subscribe to either BPI or RESNET. The energy engineers, who specialize in this from an auditing and engineering (many are PEs and all are at least mechanical or electrical engineers with college courses in the latest in energy issues and design considerations) state emphatically that blower door tests are typically not necessary.

I wonder how much of this is being driven by the manufacturers and the auditors, as opposed to sound practices. Measuring the efficiency of a building is a far cry from measuting the energy efficiency of a single piece of equipment. With literally thousands of variables, must truly believe that all of this is a best guess.


What will the homeowner’s return on investment be? $3800 in cost versus how much in energy savings over the cost of a year?

5 years?

Many homeowners smly do not have the $3800 on hand. They will need to phase in the repairs over time. Perhaps two years or more…

What do you show them and how do you quantify it?

I have a relative that received a “free” energy audit, a “free” new HE furnace, “free” new insulation, “free” new windows thanks to all you generous taxpayers.

Wake up people.

Where are you getting this data? Please post your sources.

Blower Door testing is essential in performing a Home Energy Performance Audit.


David Valley did a post over at Linked-In that has stirred up a hornets nest. He questioned the use of blower doors. All the “experts” are responding.

[quote=“jfarsetta, post:66, topic:46400”]

All of this is pretty funny. Secretaries are now getting LEED designations, just by working for firms who do the designs, because with LEED, one needs to have participated in the design process.
If this is true, IT IS SAD!!! SAD!!! SAD!! When Joe Lstiburek (he or partner John Straube speak here every 2-3 years) was interviewed on local radio a year ago, he claimed the LEED program doesn’t work!

Many governmental agencies do not subscribe to either BPI or RESNET. The energy engineers, who specialize in this from an auditing and engineering (many are PEs and all are at least mechanical or electrical engineers with college courses in the latest in energy issues and design considerations) state emphatically that blower door tests are typically not necessary.


Most engineers and architects do not have in depth building science, etc. How are they going to set an airtightness spec for duct systems (I used to test new HVAC systems also)/ building enclosures and then know the spec was met…just have a look at it??? Somewhat like a policeman without a radar gun trying to state in court, when dealing with a speeding charge, that he knows what going 120 mph looks like.

If you go back to the ASHRAE “Fundamentals” volume of 1977 and before, you will see that the “crack loss” method for determining air exchange rates as part of the process for properly sizing HVAC equipment was all that was offered. Calculate all the crackage around windows and doors, give it a pre-selected value of leakage per lineal foot and voila…you had a quantity that really didn’t mean much!!! As blower door testing became “the method”, it was found that windows and doors were only responsible for 6-22% of all air leakage!!! What about all the other leakage that the crack loss method did not account for.

In 1981, I believe, fan pressurization was added to the Fundamentals volume. In 1981, I purchased a blower door to sell air sealing work as an add-on to our blown insulation service. I went to the first full service energy consulting engineering firm (in a larger city close to our town) to try and get them interested in using our services…but with no luck!! About 7 months later, I got a call from one of the firm’s partners… “Could I come to the monthly ASHRAE chapter meeting and speak about the blower door and air leakage measurement”. The rest is history. We became a select bidder for all the retrofit work they specified for school boards etc. although we did not live in their jurisdiction!!

I have found over the years that, in general, engineers/architects picked up the finer points of energy efficiency, IAQ, etc later than those passionate about it…and I find they are the hardest group to teach new ideas to. From my own example: I have no degrees but (1) in 1990, I was hired by an engineering firm to set up and manage an IAQ and TAB (Test, Adjust, Balance) subsidiary; in 1992, I moved to the province I now live in to run the first set of energy regulations; in 2003/2004, I taught the building science course at the local university architectural faculty while the prof was away for a 2 year leave of absence…he was at MIT doing a Phd in building science.

Canada’s R2000 program was mostly built/improved at the bureaucrat/builder level except that Joe Lstibutrek had a hand in setting up the original standards. The first engineer (he’s now with one of the BUILD AMERICA partners) I dealt with in the program (1989-90) had to give “special certification” to 3 houses where my company installed HRV systems that were too small and did not meet program specs then. By today’s specs, these HRV systems are now oversized for the the homes they’re in!!

BTW, Joe, the earliest blower door set-up that I’ve seen mentioned was assembled and used by Texas Power and Light in 1968 to investigate air leakage in relation to high AC bills. This is not a new phenomenon. Get on board!

A local power company here in Texas is using gov’t funds to weatherize homes.

They go in a clean and service the HVAC, make sure the return air and supply air
are sealed properly. Add insulation in the attic up to 18" and go around with
a smoke stick and seal air leaks.

Their staff of RESNET certified auditors have found these items give people
the most bang for the buck. They encourage people to change their bulbs,
use less water, put a timer on the water heater, and keep their windows
covered. They offer low cost solutions that give back decent returns.

No blower doors or duct blasters.

They calculated how to spread out the gov’t funds to give the most people
the best energy advise for the least amount of money spent.

I know this is insulting, but commons sense is sometimes the best solution
for average people in the real world.

John, we have a similar program here in NH. I’m heading out today to do one. Each one of these jobs I have to use a blower door to record pre and post retrofit numbers. I also use my thermal imager to help with air leakage.
After the job is complete the state sends out an auditor who does a quality control inspection with a blower door and thermal imager.
NH has one of the oldest weatherization programs in the country. The program has been around since the 70s and I believe they have been using blower doors and IR now for 6-7 years.

Most of my comments on this board are because I use these tools almost everyday, I follow a procedure that has been in place for years and it works. One of the most important aspects of this program is the home is looked at as a whole system so we not only insulate, we air seal, add ventilation, which will help control moisture, and do caz testing.