Energy Vanguard Blog

Adventures in Hotel Bathroom Ventilation

Posted by Allison Bailes on Mon, Apr 18, 2016

I always look at the bathroom ventilation when I'm staying in hotels. Last month I was at the Air Barrier Association conference in Baltimore and took the photo below. Can you tell anything about what might be happening by looking at it? I didn't do a thorough investigation, but here's what I see.

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Tags: indoor air quality, moisture problems, ventilation

Can You Cool Your Home with Crawl Space Air?

Posted by Allison Bailes on Mon, Feb 1, 2016

I know it's not air conditioning season, but this story is too good to wait until summer rolls around. My friends at E3 Innovate in Nashville — you may remember them for finding the home ventilated with dead possum odors — have done it again. This time they've discovered a crawl space with an unhealthy innovation. Let's take a look at the photos.

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Tags: heating & cooling distribution, crawl space, indoor air quality, ventilation, heating & cooling

Unvented Gas Appliance Industry Falls Flat at ASHRAE Meeting

Posted by Allison Bailes on Mon, Jan 25, 2016

Unvented combustion appliances were added to the scope of ASHRAE's residential ventilation and IAQ standard (Std. 62.2) recently. The committee has begun their deliberations on the issue, and at ASHRAE's winter meeting in Orlando this month, the unvented gas appliance industry folks attempted a defense of their products. Based on the results they presented and the reaction from most committee members, I'd say they failed.

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Tags: indoor air quality, moisture problems, health & safety, ventilation

What Is the Best Indoor Relative Humidity in Winter?

Posted by Allison Bailes on Wed, Jan 20, 2016

It's been a little crackly around here lately. We're having a cold spell in Atlanta, with high temperatures right around the freezing point. As a result, the indoor relative humidity has dropped and we're getting some static electricity. Even better, what I call the Southern Lights are visible at night, too. (I've never called it that before, but hey, a man named Allison is entitled to make things up on the spot.) That's when the microfiber blanket on the bed lights up every time I move.

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Tags: air leakage, indoor air quality, moisture problems, ventilation

Another Way to Prevent Your Garage from Making You Sick

Posted by Allison Bailes on Fri, Jan 15, 2016

If you have an attached garage where you live, the odds are high that your indoor air quality is worse than a home without an attached garage. Just take a look at the photo below to see some of the sources of pollutants that can get into your home's air. How many do you see?

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Tags: heating & cooling distribution, indoor air quality, water heating, ventilation

Do Energy Efficient Homes Cause Asthma?

Posted by Allison Bailes on Thu, Sep 24, 2015

The British newspaper The Guardian recently published an article on asthma and energy efficient homes, claiming that reducing energy use in homes can hurt indoor air quality (IAQ). But wait! Asthma may not be the only thing to fear with energy efficient homes. A researcher whose report is cited says that poor IAQ also can lead to "lung cancer, chronic obstructive pulmonary disease, airborne respiratory infections and cardiovascular disease." Should we be worried? Are those airtight houses going to kill us?

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Tags: air leakage, indoor air quality, moisture problems, health & safety, ventilation

10 Essential Steps to Building a Pretty Good House

Posted by Allison Bailes on Mon, Aug 24, 2015

My friends up in Maine came up with the concept of the Pretty Good House a few years ago, and I love the idea! Not everyone can or wants to build a LEED Platinum, Living Building Challenge, Passive House. But a lot of architects, builders, and homebuyers would like to design, build, and live in houses that are better than the barely-legal, code-minimum houses that populate the market. The Pretty Good House, then, is the way to go.

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Tags: design, heating & cooling distribution, insulation, air leakage, windows, moisture problems, ventilation, heating & cooling

Psychrometrics, Part 2 - The Quantities in the Chart

Posted by Allison Bailes on Tue, Jun 2, 2015

Psychrometrics, you may recall, is the science that involves the properties of moist air and the processes in which the temperature or the water vapor content or both are changed. To understand how all that works, we need quantities and we need them to be well-defined. Some are easy to understand (e.g., dry bulb temperature and barometric pressure); others are a bit more abstract (e.g., enthalpy). Here we'll take a look at the main psychrometric quanitites, define them carefully, and tell which commonly used term you should avoid.

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Tags: moisture problems, ventilation, heating & cooling

Psychrometrics - Impenetrable Chart or Path to Understanding?

Posted by Allison Bailes on Tue, May 26, 2015

I have a confession to make: I've fallen in love with psychrometrics! After water itself, moist air has got to be the most interesting substance in building science. And the psychrometric chart, in all its many manifestations and with its multitudinous quantities, is a thing of beauty. Well, at least it is to me, and maybe it will be to you, too, after you get to know it a bit better.

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Tags: moisture problems, ventilation, heating & cooling

Is This the End of the Double-Wall, Cold Sheathing Scare?

Posted by Allison Bailes on Wed, Apr 22, 2015

Insulation is good. More insulation is better (although at some point, more may not be cost effective). It reduces the amount of heat a home loses in winter or gains in summer. You can get there by building thicker walls and putting more insulation in the cavities, or you can put insulation on the outside of the structure, as in the Perfect Wall. The photo below shows thick insulation in the cavities of a home with double-wall construction.

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Tags: insulation, air leakage, moisture problems, ventilation