Will High-Velocity AC Blow You Away?

Will High-Velocity AC Blow You Away?

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Landis Carey
Aug 20, 2010

I've been wondering about the benefits of high-velocity AC systems for some time—they seem to be the popular choice when retrofitting older homes with air conditioning. In comparison to traditional units, I've heard these smaller systems are more energy efficient and very popular in Europe. This information came from my real estate agent, who I absolutely adore, but let's face it, he's not an engineer. Though neither am I, so please chime in if you're aware of any benefits these systems offer a homeowner that I don't mention. Or chime in even louder if your experience proves there is no benefit to be gained.

Let's begin with these systems' positive attributes:


  • Duct work is smaller and more flexible than conventional AC units, making it easier to install in older, exisitng homes. High-velocity ductwork requires 1/10 the space that conventional ductwork requires.

  • Keeps up to 30% more humidity out of your home than conventional systems. This is a plus because when your environment's humidity is lower, temperatures feel cooler. Therefore, users can keep their thermostats set at higher temperatures and still be comfortable, saving energy at the same time.

  • Because air is delivered at a higher velocity than conventional systems, the fresh air introduced into a room more effectively mixes with existing air, preventing hot and cold spots.

  • These systems create gentler circulation without drafts. In the image above, AC enters the room from a vertical wall, where it efficiently mixes with the room's air for comfortable temperatures.

  • They are quieter and will cool your space quicker than their conventional counterparts.

  • Because high-velocity ductwork is more easily installed in old, existing homes than conventional ductwork is, homeowners will avoid spending money on structural alterations and cosmetic repairs, which often happens when retrofitting homes with larger, conventional ductwork.

Now to the bad news: Initial installation costs are greater if you are installing in a new construction home because high-velocity's smaller, more flexible ductwork is more expensive than conventional ductwork.

This bad news isn't so terrible, right?

Now you may ask the obvious question: Is it even possible to have AC in your home and still be green? It's a fair question and many of you will say no (including my husband), but let's face reality. When summer temperatures reach 90 degrees with humidity levels just as high and you're walking home, perhaps up a hill, in a suit, it's likely you'll be hot and a bit irritable coming in the door. And you will want to relax and cool off after a hard day of work. Or perhaps you are like me and you prefer cooler sleeping temperatures. Either way, AC is sometimes necessary, especially here in the Northeast and in my home state of Florida.

From my investigation, high-velocity AC systems are the best option for retrofitting old homes. Living in an existing home is always more green than building a new home, but that's another post. So, by choosing low-energy systems, like the one discussed here, that make living in existing homes comfortable, isn't that living a greener life than building a new home with inefficient systems? I'd love to hear your opinion!

For more information about high-velocity air conditioning systems, take a look at this Bob Vila video.

(Image: United Garibay Heating and Air Conditioning)

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