Comments on: Is This the Worst Duct Retrofit Ever?

By: Allison Bailes

Allison Bailes — Wed, 04 May 2016 06:53:40 +0000

Yes, Dixie, I've been
Yes, Dixie, I've been watching the news of Corbett's tour. We'll see him here in Atlanta next year.

By: Dixie Wong

Dixie Wong — Mon, 02 May 2016 16:20:38 +0000

I am happy that you continue
I am happy that you continue to write informative articles. Did you see the tour that Corbett is conducting? It was mentioned in HOME ENERGY's newsletter.

By: Mike White

Mike White — Thu, 28 Apr 2016 19:38:51 +0000

Craig's List and Chuck with a
Craig's List and Chuck with a truck at your service!

By: David Butler

David Butler — Fri, 26 Feb 2016 23:52:32 +0000

In reply to Andy Wahl.

@Andy, Johnny says he’s been
@Andy, Johnny says he’s been at it for 30 years. Sounds like he knows how to do bypass ‘correctly’ so as to avoid the problems you mention (as I said, a properly designed bypass will work just fine). But the efficiency impacts, while real, are hard to measure in-situ.

Here’s a great video Proctor put together using a lab setup to demonstrate the impacts: http://bit.ly/1lxxQoE.

This bypass discussion is a bit of a side-show to the main point of this article. Here’s a previous Energy Vanguard article about bypass: http://tinyurl.com/bxg4eyt

By: Andy Wahl

Andy Wahl — Fri, 26 Feb 2016 05:43:32 +0000

In reply to David Butler. David:
David: I agree we all can get set in our ways until we can experience a better way. I would encourage "Johnny" (with due respect) to do measuring of what he is recommending to see it may not be the answer. It not only reduces efficiency it can also freeze the coil in cooling and overheat heat exchanger in heating. I have a philosophy to never believe anything anyone tells me without proof. Show me the data.

By: Andy Wahl

Andy Wahl — Fri, 26 Feb 2016 05:34:52 +0000

In reply to John Proctor. John:
John: Great answer, let the data speak for itself.

By: David Butler

David Butler — Thu, 25 Feb 2016 23:41:00 +0000

+1 John Proctor. Folks aren't
+1 John Proctor. Folks aren't going to easily let go of what they've been taught and have practiced for decades.

By: John Proctor

John Proctor — Thu, 25 Feb 2016 23:31:23 +0000

@ Johnny I have to
@ Johnny I have to respectfully disagree with you. Thirty years of experience with zoning, I presume that you have found that a “properly installed” bypass reduces noise on the zone that is calling for conditioning. The bypass is based on the concept of “excess air”. However, it is important to look at more than experience (which varies between those who still use bypasses and those who do not). It is important to look at what the scientific studies show. I suggest that you take the measured data seriously. The data show what happens when the bypass is open, the capacity drops and the efficiency drops. What this means is that the capacity and efficiency are considered “excess” by opening the bypass. This is both unnecessary and counter productive. There are ways to shift part of the capacity between zones and maintain the efficiency of the unit. I respectfully suggest that you read the information from the Carrier test contained in http://www.proctoreng.com/dnld/H114.pdf
To quote:
This paper states:
“Capacity and EER drop significantly with increasing air bypass for both the air conditioner and heat pump. The capacity and the EER of the air conditioner decreased 47% and 46% respectively with an increase in bypass from 0% to 79% for DOE A test conditions.”
Note that the reduction in capacity produces an almost equal reduction in efficiency. This is because the watt draw of the condensing unit changes very little as the indoor coil gets colder.
Note the graph of Page 9.

By: Johnny

Johnny — Thu, 25 Feb 2016 09:10:54 +0000

In reply to Kris. Dumping excess air into
Dumping excess air into return is correct way to remove excess static when one zone closes. Damper may not be adjusted to correct opening position during this process , you could have variable speed furnace or air handler installed with Honeywell control board that ramps blower to correct proper airflow to each zone,this is somewhat costly but will correct flooding of refrigerant to compressor,l have 30 yrs experience and guarantee this is correct fix to your problem

By: Lee Hammond

Lee Hammond — Thu, 25 Feb 2016 02:44:29 +0000

In reply to c bigelow. I thought the same thing at
I thought the same thing at first but believe it is the perspective of the photo with the gutter being much closer to the camera.