HVAC design, Manuals J, S, T, & D, Duct leakage, Air flow, ENERGY STAR new home requirements, and more. Since heating & cooling are such a big part of home energy use, understanding HVAC is critical.

Members: 205
Latest Activity: Nov 28, 2017

Discussion Forum

joining ducts

Started by Don Fugler. Last reply by Dara Bowser Nov 28, 2017. 21 Replies

A question came up on exhaust duct connections. I have always considered screws necessary for mechanical fastening of one duct to another. I have been reminded recently that screws impede airflow and…Continue

HVAC integration – the past, the present, and the future

Started by Igor Mitbarg. Last reply by Lucifer Prescott Apr 11, 2017. 1 Reply

HVAC integration – The pastWhen the first air conditioning systems came in, they were simple mechanical “machines”, with very…Continue

Efficient furnace with maximum temperature

Started by Thaara Mar 30, 2016. 0 Replies

Furnace with maximum temperature used for melting and semi heating purpose. By this we can achieve the strengthened steel.Continue

Tags: maximun, temperature, with, funace, manufacturer

Zehnder North America seeks qualified QA agents

Started by Gary Baggett Mar 4, 2016. 0 Replies

       Hello Energy Pro’s. On behalf of Zehnder North America, I would like to put out a request for 3rd party QA/commissioning agents across North America. We are looking for Home Energy Raters,…Continue

Target superheat formula

Started by Miguel Orduno. Last reply by John Proctor Feb 18, 2015. 6 Replies

You said take wet bulb at unit not in the house am i right or did i miss understand the formula

Now for Something Different

Started by John Porterfield. Last reply by John Porterfield Jan 12, 2015. 2 Replies

Now that my wife and I are involved in BPI training and plan to conduct field test at our residence, the work scope for integrated HVAC has become more involved.   We'd like to use our efficient…Continue

Tags: test, site, BPI, heating, HVAC

Floor level return added to attic ductwork.

Started by Steve Waclo. Last reply by Bob Blanchette Dec 14, 2014. 1 Reply

Hello everyone and Happy Holidays!Attic ductwork is ubiquitous in extant, single floor, single family housing and we are all too aware of the numerous shortcomings. A number of years ago, I decided…Continue

Furnace with ECM: How to Model

Started by Barbara Smith. Last reply by Ryan Schmidt Nov 13, 2014. 5 Replies

Suppose you have a forced-air natural gas furnace.  At the end of its life, you are considering replacing it with an ENERGY STAR model.  In the cold northern states, that means 95 AFUE with an…Continue

Tags: blower, PSC, fan, ECM, gas

Exposed AC and ducts. How would you like to tackle this??

Started by Hal Skinner Sep 7, 2014. 0 Replies

Some of the things homeowners,…Continue

ENERGY STAR Furnaces & Failure of DOE Standard

Started by Barbara Smith. Last reply by Bob Blanchette Aug 15, 2014. 7 Replies

Any speculation on why DOE was not able to make its new minimum federal standard for furnaces stick?…Continue

Tags: effectiveness, cost, market, share, ECM

Comment Wall


You need to be a member of HVAC to add comments!

Comment by Don Fitchett on September 5, 2017 at 10:44am

I bet a lot here in this group can identify this refrigeration system. :)


Comment by Hal Skinner on January 9, 2017 at 4:58pm

We have been applying a radiant control coating to interior and exterior ac units and ducts for over 30 years withv great resuls.

I started a classroom for Radiantt Control Coatings a few years back.

Comment by John Nicholas on September 26, 2013 at 6:18pm

For ES 3.0 you have to verify the contractor is certified.  If he is certified he knows he has to take that measurement.  I would discuss the requirement with him and find out why he doesn't want you drilling in the cabinet.  I know you do not want to hit a piece of the coil.  The recommended practice is to use the same holes the certified HVAC companies tech used for rater measurements.

My next step is who hired you and is paying you.  They can decide not to go ES 3.0 - talk to the contractor - or depending on the paper work, refuse to pay him until he properly completes the process.  I hope it doesn't go that far.

Comment by Steven Lewis on September 26, 2013 at 6:12pm

I just go through the filter.  if it is not metal or electronic.  Leave the filter in place and poke a hole with your probe in a corner.  If you want to know the pressure drop across the filter place the probe just under the filter and compare to the number above the filter.

Comment by Bruce A. Bailey on September 26, 2013 at 5:30pm

I want to test static pressure for Energy Star version 3 in a split heat pump with the air handler in an interior closet so it does not have any return air duct the filter is in the slot at the bottom of the air handler. The inspection form requires 2 inputs a supply side static pressure (I took it in the riser plenum attached to the Air handler.) and a return side static pressure that is supposed to be between the filter (slid in the bottom of the Air handler) and the blower fan. The contractor says he doesn't think he needs to take the return side static pressure because there are not any return air ducts but he will not allow me to drill a hole in the cabinet between the filter slot and the blower. What do you suggest I do to get an accurate number?

Thank you in advance for any help you can offer.

Comment by Steven Lewis on December 17, 2011 at 2:55pm

You  havent given  enough information to make an educated guess.  How dusty was the house before?  Is it in all rooms or just a few.  is it dust or fibers from the cloth materials in the home.  If you can sweep your hand across a surface and the materiall rolls up it is fibers and is probably not coming from the duct work

Take a camera and shoot some pictures down the duct or runs and that will show you if something is in the duct system as well.  What type and efficency  filter is the homowner using?  You might check the returns and see if there are any openings to the outside of the envelope . 

when you gave "more air" how did you do that?

Comment by Judi Lyall on December 17, 2011 at 9:42am

Good morning,

   I have a client that complained that certain rooms were either cold or hot. She had 45% leakage. We gave her more air, tightened the ducts and now she called and said that the home is now getting very dusty. What is the cause and what to do next. It has gone through the summer with the air blowing thru it, I would think the the dust in the ducts are already blown out

hanks for your reply

Comment by Al Tibbs on February 4, 2011 at 2:20am
When will the ICC Codes prevent the installation of air handlers and ductwork in unconditioned attics. This practice is the biggest obstacle to achieveing the best results when retrofitting.
Comment by John Nicholas on December 31, 2010 at 1:02pm

I went out to get the mail this morning and saw my neighbor's roof.  The attached image shows what I am thinking is ice, frost on the roof.  It is obviously circular around the flue from the furnace. The flue from the DHW is separate and not in the image.  It was frosty this morning and overcast. At 8:30 most roofs have frost. By the time I noticed this and took the shot, the frost on the other roofs is gone.

Is this excessive condensation from moisture in the flue gases and does that mean the furnace has a problem?



Members (204)


Discussion Forum

joining ducts

Started by Don Fugler. Last reply by Dara Bowser Nov 28, 2017. 21 Replies

HVAC integration – the past, the present, and the future

Started by Igor Mitbarg. Last reply by Lucifer Prescott Apr 11, 2017. 1 Reply

Target superheat formula

Started by Miguel Orduno. Last reply by John Proctor Feb 18, 2015. 6 Replies

Latest Activity

KRicket Smith-Gary commented on Efficiency First California's blog post Is Health The Future of Home Performance?
"While discussing health benefits for various retrofits and new construction, please also keep in…"
22 hours ago
KRicket Smith-Gary liked Efficiency First California's blog post Is Health The Future of Home Performance?
22 hours ago
goodtidings comfort is now a member of Home Energy Pros Forum
Payal Nene posted a discussion
Tina Baldt added a discussion to the group Job Board

Hiring QC Specialist - Chicago/Evanston, IL

CMC is looking for a QC Specialist to join our growing team in the Chicago, IL area.Please see…See More
Jessica Wong posted a blog post

10 Financing Trends and Predictions for 2018

2017 brought innumerable highs and lows for the global business community. All said and done,…See More
Jim Gunshinan posted a blog post

Using God Talk—or Not—to Help the Planet?

I am always impressed with the work of Susan Shelton and the Shelton Group. So an email message…See More
David Butler posted a discussion

RESNET gets serious about modeling platform consistency

A critical element in ensuring the consistency of HERS Ratings is enhancing the consistency which…See More


  • Add Photos
  • View All

© 2018   Created by Home Performance Coalition (HPC)   Powered by

Badges  |  Report an Issue  |  Terms of Service