HVAC

Have HVAC Questions? Ask an HVAC Expert for Answers

Ask an Expert,
Get an Answer ASAP!

HVAC
This answer was rated:

what problems may I encounter not using a pant leg transition

what problems may I encounter...
what problems may I encounter not using a pant leg transition and using a plenum
Show More
Show Less
Ask Your Own HVAC Question
Answered in 18 minutes by:
7/21/2013
R.G.
R.G., HVAC Technician
Category: HVAC
Satisfied Customers: 319
Experience: 20 yrs. experience as HVAC technician, state certified contractor.
Verified

R G : Hi, I am R. G., sorry you're having trouble today, I will do my best to assist you in resolving you're issue.
R G : is this a residential air handler installation?
Customer:

no this is a commercial 20 ton unit a carrier 50 BV020-64 we are in confined space I don't think I can make this fit.

Ask Your Own HVAC Question
Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 9,155
Experience: Retired HVAC/ Electrical & Boiler contractor. Industrial
Verified
Welcome to Just Answer!

Tell us please if it for a return or exhaust system, or a supply air system.... for a supply air there can be more issues than for a return or exhaust system... the way the rest of the system is configured from ends of the each branch makes a difference as well.

Phil
Ask Your Own HVAC Question
Customer reply replied 4 years ago

it is a supply duct, vav system, with variable speed fan

Hello again, if the pant leg splits air flow evenly on the two legs evenly ....and each leg has approximately the same air flow with a VAV box down stream of the split... you should have no problems created on that basis.

Same if you use a plenum if the branches of each leg are lateral. (90 degrees to the plenum)

If the VAV box is upstream of the pant leg split or plenum you can have problems if there are not balancing dampers at the registers or in each leg. even then, if one of the legs feed an outside zone along the window areas, and the other leg feeds an inside zone.. you can have a lot of problems as the seasons change and the load on the glass reverses from a heat load to a cooling load.

The VAV should be in each leg in that case, not upstream of the split.


There are many *other issues with VAV systems of all sorts due to bad design, or problems if load is greatly reduced in a zone and air flow drops ...and you end up with air 'falling' out of the registers creating cold spots or hot spots in zone... but those do not stem from these pant leg, or plenum type constructions alone.

 

______________

 

.

Tell me what problems you are having with the system, and a bit about its history and the size of the overall system.

We can go from there as long as you rate this answer from me *positively.
.. I will hold this question open for a much larger discussion on these VAV systems engineering issues..

Phil

Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 9,155
Experience: Retired HVAC/ Electrical & Boiler contractor. Industrial
Verified
Phil and 87 other HVAC Specialists are ready to help you
Ask your own question now
Ask Phil Your Own Question
Phil
Phil
Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 9,155
9,155 Satisfied Customers
Experience: Retired HVAC/ Electrical & Boiler contractor. Industrial

Phil is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

You did one super job of explaining to me everything there is to know about this fridge. I'm looking forward to asking you questions in the future.

JimmyBagley, IA

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

< Previous | Next >

Meet the Experts:

Phil

Phil

Mechanical Engineer

9,155 satisfied customers

Retired HVAC/ Electrical & Boiler contractor. Industrial

Rick Mather

Rick Mather

HVAC Technician

3,133 satisfied customers

35 years experience, HVAC

Matthew

Matthew

HVAC Technician

2,014 satisfied customers

14 years experience in the HVAC field of service, installation, Manual J & D calculations

Kenton Guidry

Kenton Guidry

HVAC Technician

963 satisfied customers

12 years install/service experience.

Brian HVAC Guy

Brian HVAC Guy

HVAC Technician

953 satisfied customers

I have been an HVAC/R mechanic/technician for 30+ years.

Rick Ridley

Rick Ridley

UK Heating Engineer

871 satisfied customers

Retired But have had 30 years on the tools, Ex CORGI

Tom

Tom

HVAC Technician

770 satisfied customers

16+yrs HVAC/R service. Residential Commerical Industrial

< Previous | Next >

Related HVAC Questions
The supplemntal heat is not working in my carrier air
The supplemntal heat is not working in my carrier air handler … read more
Airheatman
Airheatman
Heating & Air Conditioning Contractor
6 years college
1,836 satisfied customers
Carrier 2500a keeps saying it's low on fuel and shuts
Carrier reefer 2500a keeps saying it's low on fuel and shuts down.but is full of fuel … read more
Michael Ferryman
Michael Ferryman
86 satisfied customers
I have 2 Carrier Infinity HVAC Systems that were installed
I have 2 Carrier Infinity HVAC Systems that were installed in 2008. I am trying to replace the thermostats with a 3rd party WiFi thermostat and need to know the dip switch settings on the green contro… read more
Charles
Charles
HVAC Technician
Associate Degree
91 satisfied customers
Phil, we have a Carrier Infinity Weathermaer natgas
Phil, we have a Carrier Infinity Weathermaer natgas furnacethis week the limit switch had to reset at lest 4 ties. We replaced the limit switch,ever since then the furnace runs but the top of the plen… read more
Airheatman
Airheatman
Heating & Air Conditioning Contractor
6 years college
1,836 satisfied customers
Cost to replace a expansion valve on a carrier infinity.
cost to replace a expansion valve on a carrier infinity … read more
Phil
Phil
Mechanical Engineer
9,155 satisfied customers
Need an interconnect schematic for my carrier furnance. Need
Need an interconnect schematic for my carrier furnance … read more
Phil
Phil
Mechanical Engineer
9,155 satisfied customers
I Have a Carrier gas furnace model PG9MAB060120A. The
I Have a Carrier gas furnace model PG9MAB060120A. The burners blow but the air from the heat exchange at the furnace is luke warm. Is there a problem with the heat exchange? … read more
Gaztech
Gaztech
Technician
Vocational, Technical or Trade School
1,142 satisfied customers
Have a Carrier Weather Maker 8000 ts and the light on the
Have a Carrier Weather Maker 8000 ts and the light on the front panel is blinking … read more
Billy
Billy
Journeyman Service Technician
State Licensed Mechanical Contractor
9,330 satisfied customers
We have a Carrier Infinity System Thermostat Model #
We have a Carrier Infinity System Thermostat Model # SYSTXCCUIZ01-A and the plastic "heat" and "zone" buttons are broken. We are looking for a new unit with this model number to replace our current un… read more
gotoman for ac
gotoman for ac
HVAC Service manager and owner
Associate Degree
4,135 satisfied customers
We would like to purchase a Carrier Infinity System
We would like to purchase a Carrier Infinity System Thermostat model SYSTXCCUIZ01-A. Searching for this but haven't had much luck. … read more
Airheatman
Airheatman
Heating & Air Conditioning Contractor
6 years college
1,836 satisfied customers
Im changing my thermostat from a carrier to honeywell
Im changing my thermostat from a carrier to honeywell rth6580wf. The orange wire, not sure where to connect it on the honeywell … read more
Phil
Phil
Mechanical Engineer
9,155 satisfied customers
Airheatman, Trying to source a control board for a Carrier
Hi airheatman, Trying to source a control board for a Carrier forced air furnace that a technician said was no longer available. The number is ***** obscured, looks like 3057?5 702 working with a 3012… read more
Billy
Billy
Journeyman Service Technician
State Licensed Mechanical Contractor
9,330 satisfied customers
Carrier model 58GSC065JB. Works good, but when thermostat
Carrier model 58GSC065JB. Works good, but when thermostat temp is reached, after burners shut down, sounds like the fan attempts to start up 3 times. … read more
HVAC Guru
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
I'm on service with a commercial Carrier heat pump, It wont
I'm on service with a commercial Carrier heat pump … read more
Airheatman
Airheatman
Heating & Air Conditioning Contractor
6 years college
1,836 satisfied customers
My high efficiency condensing furnace (Carrier) emits a
My high efficiency condensing furnace (Carrier) emits a terrible eye-stinging odor when heating. The furnace runs quiet and otherwise appears to be trouble free, however I see (and smell) a fresh (wet… read more
HVAC Guru
HVAC Guru
Service Technician
Associate Degree
682 satisfied customers
Have Carrier fan coil unit model FV4CNB003. Have Carrier Fan
Have Carrier Fan Coil unit # FV4CNB003. Seemed to run and change speed during operation. Is this normal? … read more
Airheatman
Airheatman
Heating & Air Conditioning Contractor
6 years college
1,836 satisfied customers
What is the wiring from txu/carrier thermostat to a
what is the wiring from txu/carrier thermostat to a non-programmable thermostat by honeywell … read more
Airheatman
Airheatman
Heating & Air Conditioning Contractor
6 years college
1,836 satisfied customers
We have a Carrier A/C with Carrier TP-PRH01 thermostat. Set
We have a Carrier A/C with Carrier TP-PRH01 thermostat. Set on hold, auto, cooling.75 dgr. A/C will run for a while and go dark.Cooling stops. eventually it will light up and cooling will begin and wi… read more
gotoman for ac
gotoman for ac
HVAC Service manager and owner
Associate Degree
4,135 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x