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3398 Washington Road
Atlanta, GA 30344
USA

773.398.5288

Advanced residential construction and home improvement consulting and owner's advocacy in Atlanta, using the latest building performance diagnostic and modeling techniques and tools. Airtightness, insulation, HVAC, ventilation, moisture, and air quality and EMF consulting for homeowners and building professionals alike.

Videos/Podcasts/Articles

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!

Filtering by Category: HVAC

How Much CO2 is Healthy in my Home? Carbon Dioxide Targets Planned and Proven

Corbett Lunsford

CO2, carbon dioxide, is a gas we exhale. It's used as a marker for indoor environmental quality because if our emissions of that are hanging out in the home, then any of our other odors, viruses, skin particles (which make up a lot of household dust), etc are also filling up the home. On an airplane, for example, which 'they' say is one of the most ventilated indoor places you can find, you can easily prove when they turn the outdoor air off while you're sitting on the ground, because the CO2 spikes upward of 2000 or even 3500 in our experience (and therefore, any of the COVID laden particles are also obviously building up). CO2 is not everything, in fact you might have a low CO2 level only because there aren't many people in the home, or the home is big enough to dilute it- you might have other markers showing the home suffers from poor ventilation, like formaldehyde, humidity, particles, TVOC, radon, and so on. But it's something that can be easily measured, so let's measure it and try to optimize for 1000 ppm as the max in homes, along with all the other factors. The two devices I use in this video, and everyday in our own home, are the Aranet4 (https://aranet.com/products/aranet4/) and the Airthings Wave Plus (https://www.trutechtools.com/AirThings-Wave-Plus-Indoor-Air-Quality-Radon). The 5 Factors of Ventilation are: https://www.youtube.com/watch?v=FOJ8fsAVUaI Learn WAY more about how to strategize the 5 Factors of Ventilation with our Ventilation Course at: https://buildingperformanceworkshop.com/ventilation See the Broan Overture system for controlling all of this: https://www.youtube.com/watch?v=slNPHuIXwnw Consult with Corbett on tuning any home, anywhere: https://buildingperformanceworkshop.com/video-consulting Watch the first-ever TV series about the Science of Homes: https://homediagnosis.tv/season-2-episodes

3 Rules for Kitchen Make Up Air Systems: Planning Home Ventilation that Performs

Corbett Lunsford

The 3 rules are: don't blow make up air on people, don't blow it on surfaces, and keep the circuit short.

See our own full kitchen exhaust and make up system at: https://www.youtube.com/watch?v=bMkvCn1sGvk

See a demo of the calculators for sizing and selecting make up air at: https://www.youtube.com/watch?v=CSmwDGxtlHU

Airtight Home Ventilation: Where to Place ERV Exhaust and Supply Grilles

Corbett Lunsford

I only recommend ERVs for very airtight homes (less than 2 ACH50), and in those cases balanced ventilation is the ONLY way to exhaust from bathrooms. More coming on that for those who are scratching their heads. If you DO need an ERV or HRV (hear the difference at https://www.youtube.com/watch?v=QOe4lluGwCg) then where do you put the supply and exhaust ports? How many CFM should they each push and pull? Here's my simple breakdown of what you'll need to consider.

Learn more about home ventilation at: https://buildingperformanceworkshop.com/ventilation

HVAC Reality Check: Are Duct Systems Dumb or Essential?

Corbett Lunsford

Just wanted to spell out why central duct systems are a central part of ANY home design. Yes, ductless mini split heat pumps are awesome. Yes, radiant flooring is comfy. Yes, lots of people use decentralized HVAC strategies around the world and are happy with them (or at least they don't know what they're missing). Duct systems can be used to filter and deliver healthy air to every room in the house- humidified/dehumidified, diluted with outdoor air, and pressure relieved for kitchen exhaust. Learn more about designing ventilation and HVAC in general at: https://BuildingPerformanceWorkshop.com Watch the first TV series about the Science of Homes: https://HomeDiagnosis.tv

Manual J or Not? How to Tell If Your HVAC Design is Bogus

Corbett Lunsford

If you ask for the HVAC design calculations for your project, you might get handed literally anything from scratches on a napkin to a 50 page jargon-filled binder. Here’s an example of a calculation that might look legit, but is actually very misleading. Learn more about HVAC Design: https://buildingperformanceworkshop.com/training Get 1-on-1 help in consultation with Corbett: https://buildingperformanceworkshop.com/video-consulting

Manual J Default Air Leakage Inputs vs. Blower Door Test ACH50

Corbett Lunsford

I'm pretty sure the awesome folks who created Manual J (like Hank Rutkowski- hear my interview with him here), and the softwares we use to run the calculations (Elite RHVAC, used here, and Wrightsoft) do not have a lot of personal experience with the test dynamics of home enclosures, and may never have actually used a blower door before. Here's a demonstration of why it's so important to respect the blower door if you're doing HVAC design for residential construction or home improvement.

Learn to perform and analyze Blower Door and Duct Tightness Tests in my 1 Day Training at: https://buildingperformanceworkshop.com/det-verifier

There are two blower door brands, both available at: https://www.trutechtools.com/system-blower-doors-and-duct-testers.html

See a tour of a full Manual J report below:

How to Hide HVAC Grilles and Replace Your A/C Faster

Corbett Lunsford

My friends, DO NOT DO THIS. Friends don't let friends put HVAC grilles, especially the central return grille, anywhere a couch might end up backing up against it. Ceilings, great. High wall, fine. Floor, not so great but probably better than this. Learn more about HVAC performance by subscribing to our channel and joining our Patreon membership: https://Patreon.com/HomeDiagnosisTV

Brilliant Basic Tools for Building Science: Psychrometric Wheel Calculator

Corbett Lunsford

To predict and prevent humidity problems, use a tool like this Psychrometric Wheel Calculator. Understand more about the relationship between tehmperature and relative humidity, absolute humidity, and dewpoint.

Join our Patreon members for as little as $5 a month: https://Patreon.com/HomeDiagnosisTV

You should be able to find one of these for sale (between $2 and $50): https://www.google.com/search?q=psychrometric+wheel+calculator

How NOT to Pick HVAC Registers and Grilles: Aria Vents Test Data Reviewed

Corbett Lunsford

One of my HVAC design clients sent me a question about these vent covers he found online, and it cracked open the whole basket of eggs. Here's a brain dump on how to look up the performance data on products like this. Here's a brand of decorative grilles that perform well- I know because I test them: https://stellarairdecorativeventcovers.com/

Learn WAY more about HVAC on our playlist: https://www.youtube.com/playlist?list=PLsc2-5fAgMq5yJOp-kliEoYVML8dS1G2f

Join our Patreon group for exclusive access to us and our work behind the scenes: https://Patreon.com/HomeDiagnosisTV

Mold House Tour and Scientific Causes: Disaster Production Home Build in Houston Texas

Corbett Lunsford

Meet our friends Anil and Nilima Mittal- they're suing the biggest production home builder in the USA. With help from Jason Earle, 20-year mold inspection veteran, we tell the story of how this mold disaster of a brand new home began, and how their health has suffered because of it.

Get your own simple mold test: https://GotMold.com

Become supporters of our work, just like Anil, and join our Patreon group for as little as $5/month! https://Patreon.com/homediagnosistv

HERE’S A SEPARATE VIDEO WITH ANIL’S TIPS AND TRICKS ON THE LAWSUIT ALONE:

ERV Setup Testing/Commissioning, Using Pressure Curves to Measure Airflow

Corbett Lunsford

Using a Renewaire SL70 energy recovery ventilator and a TEC DG-8 pressure gauge, Corbett demonstrates how to set the low and high speeds on an airtight home's balanced ventilation system.

See this ERV line at: https://www.renewaire.com/our-ervs/single-multi-family/sl-series

Get the DG-8 to test your own stuff: https://www.trutechtools.com/tec-minneapolis-dg-8-digital-pressure-gauge-kit.html

Ventilation design course: https://buildingperformanceworkshop.com/ventilation

5 Factors for Ventilation: How to Plan a Healthy Home

Corbett Lunsford

The 5 Factors for Ventilation are:

  1. Circulation

  2. Capture/Filtration

  3. Humidity Control

  4. Dilution Air

  5. Pressure Relief

This way of approaching ventilation design is condensed from hundreds of hours consulting on home projects across North America- let me know if this way of thinking about ventilation is missing anything, we're pretty sure it's a comprehensive guide! Check out the ventilation course: https://buildingperformanceworkshop.com/ventilation

The ventilation brands I refer most include:

https://Broan.com
https://AirCycler.com
https://Renewaire.com