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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

The List of HVAC Installers Who Respect Science and Math

Corbett Lunsford

Welcome to The List. It's free to view, free to be listed on, I have no interest in stealing anyone's information or making a few bucks on a kickback:

https://homediagnosis.tv/hvac-installers

I've had people from Alaska to Manhattan asking where to find an HVAC installer who even understands how to read a Manual J calculation, and just assuring them that 'they're out there' is getting boring. Here is a FREE directory of those people, SELF-SELECTED. I am NOT vetting them. They vet themselves.

Good luck to us all.

Different Room Temperatures & Outdoor Design Setpoints: Alex Meaney and Dustin Cole GO OFF

Corbett Lunsford

Why do people ask for specific HVAC stuff, and do they really need what they're asking for? Let's dive deep into the design and installation of non-mainstream HVAC requests, like different target room temperatures in a home, or outdoor design temperatures that are higher than the 99% hottest we normally use.

See Dustin Cole's interview at: https://youtu.be/1Iiho2cm2LY

Find Dustin at his family business Cole Air: https://www.airconditioninglakecharles.com/

Alex Meaney has made several videos with me so far:
Manual J Deep Dive https://www.youtube.com/watch?v=LEKEMI05dJE
Manual S Deep Dive https://www.youtube.com/watch?v=LGhE4XwbDDE
Duct Design and Existing Home System Replacements https://youtu.be/h5629tWpR9c

Find Alex at: https://MeanHVAC.com

See how HVAC pressures can affect rooms when the doors are closed: https://www.youtube.com/watch?v=orp-sXTjTPw

Borderline of Balanced Ventilation: When Bath Fans Won't Work, and an ERV Becomes Necessary at Home

Corbett Lunsford

We almost never recommend that our clients go with Energy Recovery Ventilators (ERVs) for efficiency reasons- it always comes down to the air tightness of the home. At a certain point, bath fans all over the home stop being helpful and actually become a serious liability for indoor pollution, humidity control, and predictions of performance overall. Let's dive into the free online calculator (https://www.redcalc.com/depressurization-analysis/) that I use in most of my consultations, and how to evaluate the numbers it generates.

Take my Ventilation Training and learn all that I know about this complex topic: https://buildingperformanceworkshop.com/ventilation

Get trained and certified by me to run blower door and duct testing: https://buildingperformanceworkshop.com/det-verifier

Duct Design Tips & Replacing Furnaces with Heat Pumps with Alex Meaney

Corbett Lunsford

We're back again with my HVAC design calculations trainer Alex Meaney (https://MeanHVAC.com), to talk about ductwork and connections and filters and how to get all this right when replacing an old system in existing homes.

Watch my first two videos with Alex: Manual J Load Calculation https://www.youtube.com/watch?v=LEKEMI05dJE

Manual S Equipment Selection https://www.youtube.com/watch?v=LGhE4XwbDDE

Mystery Problems in New Home SOLVED by Builder Using Diagnostics: Scott True, Dimora Homes

Corbett Lunsford

Scott True has been building spec and custom homes outside Austin TX, and he impressed me from the first time we worked together. To see some of the experiments he's running to make performance homes more affordable, watch Matt Risinger's 40 minute follow along at one of his builds: https://www.youtube.com/watch?v=fjwjeoLi6X0

IT IS NOT ROCKET SCIENCE. IT IS NOT ROCKET SCIENCE. Say it back, everybody, and spread the word. Find Dimora Homes at: https://dimorahomes.com/

Level 15 nerds get their diagnostic tools at: https://TrutechTools.com

Bad IAQ Product Review: Panasonic WhisperAir Repair

Corbett Lunsford

In short, stay away from things like this. Here's our understanding of why they're so experimental. The ACTUAL solution to making your home's air healthier is the goal of ALL of our videos on this channel, so subscribe, but FILTRATION is the only proven solution that produces no side effects for indoor chemistry. Here's how to choose filters for your home: https://www.youtube.com/watch?v=HykPt4MO2SY

To learn TONS more about indoor chemistry, watch our HOMEChem playlist all about it: https://www.youtube.com/playlist?list=PLsc2-5fAgMq7fRE6q0uWx-2F_EqBd4S_n

HVAC Training Advice from an HVAC Pro Technician

Corbett Lunsford

Dustin Cole is a 23-year HVAC veteran (and a proud Patreon member of ours- join him at https://Patreon.com/HomeDiagnosisTV ), and he has successfully transformed his heating and cooling company from a regular old family business into a leader in delivering performance-based HVAC systems, using diagnostics and computer analysis. IT IS NOT ROCKET SCIENCE. IT IS NOT ROCKET SCIENCE. Say it back, everybody, and spread the word.

Find Cole Air at: https://www.airconditioninglakecharles.com/

Latest HVAC Trade Show: Highlights Tour of AHR EXPO 2023 (ERV, air cleaning, humidity, & heat pumps)

Corbett Lunsford

Ventilation! Filters! Blue Lights! Dehumidifiers and humidifiers! Tankless heat pump water heaters!?! Lots to see this year, here are my thoughts on applications of some of these products and systems.

0:20 Renewaire EV series ERV: https://www.renewaire.com/our-ervs/single-multi-family/ev-single-multi-family/

2:27 Bath fans

3:13 Broan AI series ERV: https://www.broan-nutone.com/en-us/broan-ai-series-fresh-air-systems

5:08 Spinning enthalpy wheels

7:57 Side effects of active air cleaners

9:52 Electric fireplaces: equally romantic?

10:14 Passive house multifamily research on long-term ERV performance with Jason LaFleur

11:58 Make Up Air dehumidification option

12:50 Humidification for homes with SteamOVap Modulating Humidifier

14:27 Atmox crawlspace ventilation control system

16:31 Parmesan cheese

16:36 Sealed combustion or power-vented?

16:55 Party load mobile air conditioners

18:31 Mitsubishi Hyper Heat Sumo Heat Pumps: https://www.mitsubishicomfort.com/residential/products/wall-mounted-heating-and-cooling?modelID=MSZ-FS

19:49 Lennox's biggest customers are production builders (why does that sound so fishy?)

19:56 Mr. Cool DIY Ductless Mini Splits

21:59 Underground duct thought experiment

23:02 Reflectix duct insulation system

25:16 Problems with spray foam insulation for ducts

25:49 Flex duct configurations

27:55 Duct cleaning equipment

28:44 Tankless heat pump water heater?

32:54 Directional vents and Manual T

34:22 The only ceiling fans I saw at the whole show?!?

34:25 The most beautiful woman in the world

Basement in Florida? Why Mold Took 20 Years to Fail this House...

Corbett Lunsford

A very cool client of ours named Niko came to us with a wildly different home issue- a finished basement. In Florida. That's vented to the outdoors. Watch us tour the home being renovated with Tony Gomes, my Tampa go-to-guy for advanced diagnostics on existing homes. We explore how it's possible that mold was held at bay for 20 years, until Niko did a 'good' thing and replaced an old HVAC system with a VRF (variable capacity) heat pump.

Find the brilliant Tony Gomes and Faraday Energy in Tampa Bay at: https://faradayenergy.com/

Test your home for airborne mold with this easy kit: https://GotMold.com

What Size Humidifier or Dehumidifier Do I Need for my Home? Humidity Calculations Demo

Corbett Lunsford

This is mathy, but it’s not anything too difficult for anyone to understand I think. There are lots of nuances and caveats, which I think make the whole thing more interesting! Ideal absolute humidity range is ~35-65 grains per pound.

∆Gr/lb = Inside gr/lb - Outside gr/lb

Gr/hr = ∆Gr/lb x CFM x 4.5

Lb/hr = Gr/hr / 7000

Lb/day = Lb/hr x 24

Gal/day = Lb/day x 0.12

Pints/day = Gal/day x 8

Tips for HVAC Quality Control Targets and Specs for Builders and Contractors

Corbett Lunsford

Controlling a home's performance is pretty simple as an idea: set targets, and verify that they were met. In reality, it's a lot more complex, which is why we need to talk about the foundations for thinking through what quality control methods you'll need to use to achieve your specific goals for the specific home where a specific family will live.

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