Wednesday, July 11, 2018

The Important Stuff You Need to Know About Ceiling Fans

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Here are a few basic principles that many people don’t understand
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Here we are in the middle of air conditioning season.  So why don't we chop down some myths and misconceptions about ceiling fans?

What got me on to this topic was a video of a fan with blades that hide on top of the fan when the fan is turned off. Sounds clever, but it's a ridiculous idea.

Anyway, here are seven things about ceiling fans that a lot of people seem not to know.

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from Building Science http://www.greenbuildingadvisor.com/articles/dept/building-science/important-stuff-you-need-know-about-ceiling-fans

Wednesday, June 27, 2018

An Update on the Residential Ventilation Debate

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Here’s what you missed at the ASHRAE 62.2 committee meeting last week
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It's been a while since I've written about what I had been calling "The Great Ventilation Debate" back when Joe Lstiburek was battling the ASHRAE 62.2A standard for residential mechanical ventilation systems established by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. Among other requirements, the standard requires a home to have a mechanical ventilation system capable of ventilating at a rate of 1 cfm for every 100 square feet of occupiable space plus 7.5 cfm per occupant. residential ventilation committee. The 62.2 committee meets in person twice a year at the two ASHRAEAmerican Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). International organization dedicated to the advancement of heating, ventilation, air conditioning, and refrigeration through research, standards writing, publishing, and continuing education. Membership is open to anyone in the HVAC&R field; the organization has about 50,000 members. conferences, and they just met last Friday and Saturday in Houston, Texas.

A few things have happened over the past few years, so let me give you a brief update.

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from Building Science http://www.greenbuildingadvisor.com/articles/dept/building-science/update-residential-ventilation-debate

Thursday, June 21, 2018

Do Solar Panels Need to be Cleaned?

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How the accumulation of dust, pollen, and bird droppings affects the energy production of a PV array
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I was at my brother’s house in Lee, New Hampshire, recently and looked up to see that his photovoltaic(PV) Generation of electricity directly from sunlight. A photovoltaic cell has no moving parts; electrons are energized by sunlight and result in current flow. (PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow.) panels looked a bit dull (see Image #2 below). His PV array is easy to get to — the long north slope of his roof has a walkable 5:12 pitch — so we went up and took a closer look.

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from Building Science http://www.greenbuildingadvisor.com/blogs/dept/building-science/do-solar-panels-need-be-cleaned

Wednesday, June 13, 2018

Simple Steps to Improve Air Conditioner Performance

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If your air conditioner struggles to keep up in the heat, these measures can help
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It's getting hot out there. Here in the Southeast, we love our air conditioning.  In fact, without air conditioning, far fewer people would live in places like Houston, Hattiesburg, and Sopchoppy. And that's true for the hot, dry places, too, like Phoenix, El Paso, and Boron.

So if we're going to have air conditioning in our homes, we want it to work.  It should be effective and efficient.  It should keep us cool without creating new problems, such as excessive noise, bad indoor air quality, or comfort that varies from room to room.

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from Building Science http://www.greenbuildingadvisor.com/articles/dept/building-science/simple-steps-improve-air-conditioner-performance

Thursday, May 24, 2018

Phenolic Foam Insulation Revisited

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Can we put to bed the corrosion concerns with this insulation?
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A particularly well thought-out and thorough question from longtime GBAGreenBuildingAdvisor.com reader Aaron Birkland on the pH of phenolic foam and its possible corrosive nature prompted me to follow up my original blog on Kingspan’s Kooltherm rigid insulation.

Aaron has two main questions:

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from Building Science http://www.greenbuildingadvisor.com/blogs/dept/building-science/phenolic-foam-insulation-revisited

Wednesday, May 23, 2018

How to Read Manual J Reports

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If you know what to look for, it’s easy to check for accuracy
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When you enter the world of building science — whether through building a house, becoming a home energy rater/building analyst, or just hanging out in cyberplaces like this — everyone talks about the importance of getting actual heating and cooling load calculations based on ACCA Manual J. A great number of HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. contractors sell and install oversized equipment with air distribution systems that don't work because these contractors base their choices on rules of thumb.

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from Building Science http://www.greenbuildingadvisor.com/articles/dept/building-science/how-read-manual-j-reports

Wednesday, May 9, 2018

Proper Sizing Isn’t the Real Reason for HVAC Design

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Yes, size matters, but another factor matters more
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Many people seem to think HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. design means you get a load calculation (Manual J in the ACCA protocols) so you know what size system to put in. Hey, that's a great start. It's way better than just using a rule of thumb or Manual E (for eyeball).

But there's so much more to real HVAC design than simply finding out how much heating and cooling a building needs when it's at design conditions. And we might as well start with the fact that my first statement is incorrect: The load calculation does not tell you what size system you need.

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from Building Science http://www.greenbuildingadvisor.com/articles/dept/building-science/proper-sizing-isn-t-real-reason-hvac-design