Sustainable Building Forum

Found an energy saving product called FlexFlow Elbow by Thermaflex. It is like a brace that straps over the outside jacket of flexible duct to form it into a 90-degree elbow. You can use it on any size of duct in attics or commercial spaces. It improves airflow efficiency by keeping the duct from kinking at bends. Their website is www.flexflowelbow.com (http://www.flexflowelbow.com)

Welcome to Informed Building HVAC PRO!

So do you have any experience with these FlexFlow Elbows?  I'm very curious about them, especially now that I see they received an honorable mention at the 2007 AHR expo for ventilation innovation.  This looks like exactly the kind of innovation sustainable, green building needs - not just more energy efficient, but cheaper too.

Here's an excerpt from ASHRAE for those who may also be interested:

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The FlexFlow Elbow from ThermaFlex eliminates the need for metal elbows that require sealant and insulation. FlexFlow Elbow fits flex duct sizes 6 to 16 in. (152 to 406 mm), installs in about 30 seconds, can be retrofitted on existing installations and costs substantially less than metal elbows.

http://www.ashrae.org/publications/detail/16039

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Recently, I've seen FlexFlow Elbow specified on multiple projects around the country. Been on the market about 5 years. Seems to be gaining more recognition and acceptance lately because of its use in saving energy. We've used them - can be installed on new projects or retrofit existing flexible duct installations to improve airflow and save energy. More Mechanical Engineers and Builders need to know about them.

We'll do our best to spread the word - I'm going to add FlexFlow Elbows to our directory.  Thanks again for letting us know about this product.  Based on our experience, a lot of duct contractors in our area don't even put in hard elbows - they just run flex all the way.  Sadly, most homeowners - and perhaps even the contractors themselves don't understand the implications.

More info on FlexFlow Elbow from Supply House Times:

Wheeler On HVACR: New HVACR Technology — Other Products
by Jim Wheeler
May 4, 2004

Something that I wish we could get more HVAC installing contractors to use is another simple and inexpensive new device from Thermaflex (Abbeville, S.C.), the FlexFlow Elbow. What does it do? It is made of two adjustable plastic straps that are connected together at a 90º angle, which are used to make smooth 90º connections of flex duct to diffuser boots. Back when galvanized elbows were commonplace, such devices weren’t needed. However, whenever flex duct is the only connector, something (like this) is needed to ensure that each diffuser receives proper air flow.

More info on FlexFlow Elbow. HVAC Product Insider Review.

http://www.flexaboot.com/FFE/HVAC_Product_Insider.htm

So it looks like Flexaboot is manufactured by the same company right?

FlexFlow Elbow and FlexaBoot (FlexaBoot is an acoustical sound boot used with return air grilles in plenum return ceilings - much more economical than sheet metal return boots - also has been acoustically tested) both are manufactured and sold by Thermaflex. www.thermaflex.net. I've installed and recommend both.

Here is a video from YouTube (worth checking out) showing how FlexFlow Elbow increases airflow and saves energy.

http://www.youtube.com/watch?v=ucl3x9IFmvo

More info on the internet regarding FlexFlow Elbow.

This is from Air Conditioning Heating Refrigeration News - 2004 Dealer Design awards.

Silver winner FlexFlow Elbow, manufactured by Flexible Technologies Inc., Thermaflex Division (Abbeville, S.C.) also captured high marks and high praise from the contractor-judges. As one remarked, “This will improve airflow and quality of installation for consumers, if it is used.”

The FlexFlow Elbow straps over the duct outer jacket at diffuser connections, forming a 90-degree elbow. According to the manufacturer, its one-piece design fits all brands of commercial and residential flex duct sizes from 6 to 16 inches. The contractor-judges were not surprised to find out that the product was invented and designed by a contractor.

I saw FlexFlow Elbow at the Comfortech show in St Louis last week.

By far one of the most popular and talked about products.

As a contractor, I'll use it everytime.

It solves a major problem, saves energy, and saves me money.

I only wish I would have thought of it!  :)

Welcome to Informed Building HVAC installer!  We're looking forward to hearing more about your experiences in the HVAC industry in the future.

I saw the FlexFlow Elbow product listed as a "Green" product on a site

called www.RateItGreen.com.

The new Garmin building in Kansas City has both FlexFlow Elbow and FlexaBoot specified on it.

Its great to see an internationally known company like Garmin choosing energy saving products.

  FlexFlow Elbow  Seems to be gaining more recognition and acceptance lately because of its use in saving energy.

It's funny how such a basic premise as unimpeded airflow has taken so long to work itself into commercial products in the market.  (!)

Yes clever.  However had the makers of these systems done their homework in the first place, would be a moot point.

You are right BG1 regarding doing it right.

When I first saw FlexFlow Elbow I did the "flat forehead"!

I would like to see more simple yet effective products like FlexFlow Elbow on the market.

Imagine all the energy that could be saved if all flexible ducts installed worldwide were unimpeded!

I first saw FlexFlow Elbow at the 2002 ASHRAE show in Atlantic city.

Our company made it a standard to install them on diffusers that had 90 degree bends.

The mechanical engineers we work with love them.

Cheapest and fastest way to guarantee airflow through the flex duct.

We use these Flex Flows all the time. You always have the right size because the they are adjustble. Cutomers like them because they can see where their airflow is better.

VERY clever indeed! Looks like this product will work on commercial buildings or homes. I checked the flexible duct in my attic. All of my ducts are choked off. Definitely need to eliminate a few kinks where the ducts are connected to taps and register boots. Seems simple enough based on the youtube video.

Anyone know where I can buy FlexFlow Elbows in Southern California?

Hey Build Right,

I know FlexFlow Elbow is made by Thermaflex and their website is www.flexflowelbow.com.

Hope this helps!

I noticed the recently published ASHRAE Guides to energy efficiency for schools, retail buildings and small office buildings elude to installing a "durable support" when using flexible duct to make an elbow.

This evidently is the FlexFlow Elbow mentioned above.

The description in the guides coincides with the written spec on the FlexFlow website.

My experience has been - kinked flex duct is just like your kinked garden hose - no flow.

Great to see a product address a major concern in the industry.