The Latest from the Energy Vanguard Blog

hvac duct flex poorly supported reduced airflow comfort efficiency
Posted by Allison Bailes on October 19, 2012
I like flex duct. Really! In fact, I did an interview yesterday for the Energy Saving in the Home Radio Show and surprised the host, I think, when I said that to him. He's an HVAC contractor himself and is used to building science types being purists on the use of rigid ducts. (You can catch the...
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hvac duct design strange plenum configuration jellyfish mating
Posted by Allison Bailes on September 19, 2012
Every once in a while I come across someone's workmanship that leaves me in awe. I see it and realize that I am looking at something unique, a piece of work (in all senses of that phrase) so bold that it may never be surpassed. The one I'm about to show you is such a piece.
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hvac duct robot ductbot condensation
Posted by Allison Bailes on September 12, 2012
I've seen it over and over: The central air conditioner's ceiling vents raining down onto the floor. The insulation liner on the duct in the crawl space holding a gallon or two of water. The office that has spots appearing on the ceiling. It's not uncommon at all, although it should be.
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Getting HVAC design advice from Good Housekeeping magazine isn't a good idea
Posted by Allison Bailes on September 10, 2012
Spice up your relationship with these seven sexy suggestions! Give your skin the youthful glow of radiant good health! Master that new mixer with these garden fresh recipes! Calculate the number of BTUs per hour that your home needs for air conditioning!
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Oversized air conditioner
Posted by Allison Bailes on August 24, 2012
Apparently, I haven't written a single article this summer about oversized air conditioners. Shame on me! I've written several in previous summers, mostly about how HVAC contractors bypass the HVAC design process by using rules of thumb and how they mess up the Manual J load calculations when they...
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hvac mini split heat pump duct rigid elbows waiting
Posted by Allison Bailes on August 16, 2012
Mini-split heat pumps and ductless go together like peanut butter and jelly. Or do they? If all mini-splits were ductless, then why were those rigid elbows sitting on a jobsite I visited recently? That home is going to be heated and cooled entirely with mini-split heat pumps.
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Release the Kraken! The Ductopus Kraken!
Posted by Allison Bailes on July 9, 2012
Just a quick little post today to show you the new image I put together. Last year I wrote an article about a type of duct system that's just a complete mess. A lot of home energy pros call it the ductopus. It's just a radial system installed without any real design behind it. The ducts all radiate...
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Building science secrets for home builders and remodelers
Posted by Allison Bailes on July 2, 2012
The title of this article refers not to the two framers charging the house with a large timber but to the framing timbers already installed above the porch. Home designers, builders, and framers aren't used to thinking about the building envelope and thermal bridging. They think more about...
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hvac flex duct distribution system in unconditioned attic
Posted by Allison Bailes on May 23, 2012
Flex duct. It's ubiquitous now in homes with forced air heating and cooling systems. It's easy to install. It's cheap. The installer can show up and rough in a whole duct system without ever having seen the house before and without having a duct design. I'm not saying that's a good thing.
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hvac air conditioning latent sensible capacity load sweat
Posted by Allison Bailes on May 15, 2012
As I sit here on a nice cool May evening, getting ready for my trip to New England tomorrow, I'm thinking about sweat. And that makes me think about air conditioning. It may seem like it doesn't make sense, but when you twist your mind around in just the right way, it does. Really! And what I'm...
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