Home performance articles and stories from the field with internationally respected building forensics guru Corbett Lunsford at the Building Performance Workshop. Hear new episodes of the Building Performance Podcast, see new videos from the Home Performance YouTube channel, and learn all about how diagnostic testing (more than an 'Energy Audit') can make home improvement and new home construction a proven process!
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Charlie Weschler sits down with Grace and Corbett and gives fascinating examples of the complexity of indoor air chemistry. He is an air quality legend, a professor on 3 continents, and one of the nicest guys you'll ever meet. More at: http://HomeDiagnosis.tv/homechem
Corbett talks through the basis of design for his family's upcoming house construction in Atlanta, GA. Subscribe to stay tuned for videos during the build! To learn more about the high performance building products being used, click below:
475 HIGH PERFORMANCE BUILDING SUPPLY
GEORGIA-PACIFIC FORCEFIELD SHEATHING
MITSUBISHI ELECTRIC COOLING & HEATING
ULTRA-AIRE VENTILATING DEHUMIDIFIERS
CHRONOMITE POINT-OF-USE WATER HEATERS
See how Corbett teaches home performance to the uninitiated after having given this presentation 214 times across the U.S. on the Proof Is Possible Tour. Special thanks to the tool companies and all other sponsors of the upcoming TV series 'Home Diagnosis' who have invested in making home performance a mainstream topic:
Phil Rivas of Fantech shows Corbett around the Fantech booth at the International Builders Show 2018. Demonstrations of Inline Kitchen Exhaust hood with silencer, Energy Recovery Ventilator with balancing registers, HEPA filtration, and Dryer Booster Fans. Learn more at http://Fantech.net
Welcome to the #DryVault, a super airtight, insulated, and dehumidified tool shed for the Building Performance Workshop's diagnostic tools in Atlanta, GA. Corbett will be helping homeowners make higher performance decisions on home improvement and new construction in Atlanta from this home base, and we can't wait to show off the framing and airsealing systems used here! For more on the airsealing products used, check out 475 High Performance Building Supply.
Today I talked with Bryan Orr of the HVAC School Podcast about why home performance is the future of all residential construction and home improvement.
This week to illustrate 'Rocking the Client' Corbett broadcasts right before his Earth Day celebration keynote at the U.S. EPA's Region 4 headquarters in Atlanta! Danny Orlando, longtime supporter, is now a client- but it took 5 years to get here!
If you've asked yourself whether energy efficiency really sells homes, you're asking the right question. Go way beyond efficiency into the quality control metrics that can prove a home is worth the money, whether you're on the buyer or the seller side. Home performance diagnostics are here to stay- don't get left behind!
Recorded at Orange County Association of REALTORS during the Proof Is Possible US Tour- special thanks to Eileen Oldroyd, Joanne Frank, and Laura Reedy Stukel for making it happen!
I was going thru the videos in the training portal. Overall, I like your videos. However, every now and then, a portion of one leaves me less than satisfied with the answer. Usually, my disatisfaction is because you are rushing through and just skimming the details and explainations. I realize that your trying to limit the video's length and accept it.
However, I found one video that had something that you brought up, but didn't explain that frustrated me enough to write. The video is in the training portal, 'Mastermind Series Jan 2015' at 30:01 minutes in. Your talking about system airflows and you bring up NCI. You go to say how they add up supply airflows, return airflows, and compare it to what the airflow should be to get leakage. You say that that is wrong but don't explain. You finish by saying that system airflow needs to be measured at the blower.
So, the question I have is: Are you objecting to comparing either the supply or return airflows to what the system airflow SHOULD be (i.e. not measured) or something else?
Would you agree with the following?
(Equipment airflow) - (sum of supply register airflow) = (supply side leakage)
(Equipment airflow) - (sum of return register airflow) = (return side leakage)
Equipment airflow to be measured at or near the blower by one of the several methods. I am calling it equipment airflow and not system airflow just to be clear that it is what the fan actually produces.
Finally, are you doing full manual J's or just block load calculations to get ballpark numbers?
Great question, and I'm happy to clarify what I meant! Thanks for letting me know when my broad strokes don't actually answer your question and leave you frustrated- I always want to give a full picture of what home performance testing actually means.
My issue with measuring the supply airflows and return airflows, and inferring duct leakage from that is:
- How do you know what airflow the equipment is producing unless you measure the actual airflow at the equipment? You can use a calculation like 400cfm x tons of A/C, but what if it's heating season, 20 degrees outside, and the NEST thermostat won't let you disable the compressor's service disconnect and still run the air handler? Also, what if the installer targeted 350cfm per ton, or 450cfm?
- Even if you measure the equipment airflow, you won't be measuring the equipment cabinet air leakage, which is almost always there. In fact, the IECC duct leakage test assumes that 25% of all the duct leakage will be in the cabinet in new construction.
- The only way to measure duct leakage is to perform a duct tightness test, or for a quicker and more localized look, perform a pressure pan test during blower door testing.
- Measuring airflow is notoriously difficult. What tool and technique are we using? Pitot tube has high user error, passive flow hood (balometer) is not accurate for residential grilles and low flows, and anemometers need to be corrected for net free area of the grilles. Lots to scratch your head about, and it turns out the best way to measure airflow in the 21st century is still a plastic garbage bag.
To answer your final question, if all you need is a ballpark number, a block load is fine, but I always do a full room-by-room load calculation if I'm being paid to do an actual Manual J.
Hope that helps, and keep the questions coming!
Building performance testing expert Corbett Lunsford and Pete Sanders take you behind the curtain at the soon-to-be-opened Sanders Home Services showroom in Washington Township, New Jersey (outside Philadelphia). See the best hands-on demonstration of home performance outside the #TinyLab! Visit Sanders Home Services online at: http://www.sandershomeservices.com/