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

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

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

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

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

Tips for High Performance Home Floorplan: Designing Out Condensation, Odors, Discomfort, and Hassle

There are so many simple tricks you can incorporate into a home's layout that will improve performance, including closet orientations, bathtub and toilet locations, mechanical shafts, room arrangements, and useful buffer spaces.

Gas Stove Reality Check: Why Banning Gas Cooking is Not the Whole Story

As we've learned, and continue to learn, from the Alfred P. Sloan Foundation's 'HOMEChem' and 'CASA' experiments (https://indoorchem.org/projects/), the chemistry, microbiology, and physics of the indoors is complicated. That's why doing something 'nice' like banning the manufacture or sale of gas cooking ranges might be a misguided step that'll make regulators feel good, but leave us hanging on a TON of other side effects that are still not addressed.

Learn to select and install a kitchen exhaust hood: https://www.youtube.com/watch?v=y08HOnzafM8

See our ultimate kitchen exhaust system: https://www.youtube.com/watch?v=bMkvCn1sGvk

See Broan's SmartSense Infrared Heat Sensing range hoods: https://bestrangehoods.com/product/built-in/hbn1246ss

See AirCycler's RangeRelief make up air controller: https://www.aircycler.com/products/rangerelief

HVAC Reality Check: Are Duct Systems Dumb or Essential?

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

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

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:

Mold Inspection Tips from a Pro: What to Look For with Jason Earle from Got Mold?

Our friend and mold inspector Jason Earle has seen a lot, and believes it's important for normal people to know more about how to look for and test for mold in homes.

See the other videos in this series:

• Jason's own mold exposure as a child, and the test kit he invented to help other families like his: https://youtu.be/nylh-tNHbZg

• This home's horrific full inspection, and a dive into the building science that caused this disaster: https://youtu.be/x_jAxHZ-zLE

• Legal advice from a homeowner who's fighting back: https://youtu.be/aQtO22Yrnrc

• Check out the GotMold? Test Kit: https://GotMold.com

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

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

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