Page 1 of 4 1234 LastLast
Results 1 to 13 of 42

Thread: Return Air

  1. #1
    In reading up on HVAC systems it would seem that most people have systems with returns in each room in the house!!

    My system and most of the systems I have seen in my area have one big return.

    Is this a good solution or should the contractor have put in multiple returns?

    Oh! I live in centeral Georgia..


    Thanks for the input

    AB

  2. #2
    Join Date
    Aug 2003
    Posts
    1,841
    Originally posted by andrew boyce
    In reading up on HVAC systems it would seem that most people have systems with returns in each room in the house!!

    My system and most of the systems I have seen in my area have one big return.

    Is this a good solution or should the contractor have put in multiple returns?

    Oh! I live in centeral Georgia..


    Thanks for the input

    AB

    They do that alot in the south,returns in each room is better.

  3. #3
    Thanks!!

    I think the HVAC contractors in the south need training up north :-)

    LOL

    AB

  4. #4
    Join Date
    Jun 2004
    Location
    4H: Hot, Humid Houston H.O.
    Posts
    3,304

    Return practices

    Clearly it's better practice to have multiple returns, especially serving each bedroom. I've seen some houses with one door which closes off the bedrooms, unfortunately it also closes off all the bedroom supply ducts from the one return which is located elsewhere in the house. Those houses have lots of CFM trying to pass under that door -- be thankful if you don't have that design.

    Many older houses have duct design which is kind of neglectful, with resulting excessive vacuum in the return (and excessive External Static Pressure the equipment must work against). If that is your situation, and you can afford to spend a few hundred, you can correct both problems at once by adding return capacity and having it located in the bedrooms. Once you have done that, assuming you have generous return capacity and filter area, you will be free to use almost any filter you want without harming the equipment or airflow.

    Here's an opinion many will find disagreeable on this board -- I am of the opinion those notorious 3M filters are not inherently a faulty product (although I don't use them myself). But... if a duct system is defective a restrictive 3M will make problems worse, and I believe it when they say that can kill a system. Bad duct system, bad results all around -- but it could be the duct system which is defective and not the filter. Good duct system, no worries. The biggest problem I see is too many A/C guys who don't have any instrument with which to measure ESP.

    Hope this helps -- P.Student

  5. #5
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    p student,

    IMHO. The 3M is a problem ,in that it load up too fast,change weekly to be safe,even if the duct system can handle them,they are not a good or cost effective solution.

    Beyond that,any media,of pleated filter may be too restrictive for the otherwise good duct system.

    Had a customer,new home,in warranty using 3M pleated,wants to know why the system wasn't designed to handle them.

    Honest answer:It could have been ,however new construction is a very competitive market,if he had bought the optional media filter upgrade,the price would have included larger return ducts ,to accomodate the media filter.Or he could have paid to have them sized to handle 3Ms.So ,yes we could have designed to use better filters,but the customer nor the builder asked to get a price to do so.In this case,the customer met with us,and was presentd all the upgrades and choose none.

    Bottom line,if the system has acceptable ESP,with the filter it was designed to use,it is a good design.

  6. #6
    Thanks for the information.

    My return is located just below the unit whish is installed in the Attic. The return duct goes from the filter Return intake which is huge and has a very large pipe leading up to the system. I can alsost get inside it and stand up. so I would have to think it has enough capacity to handle the air it needs.

    Problem is I have Three systems and each has its own return all located in the same general living space and services a diffrent wing of the house so I think the return air is pulling the incorrect Air

    AB

  7. #7
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    Maybe ,maybe not,if any of the returns is in a room,that has supplies from another system,it's not the best,unless it's on the "edge" of that room,adjacent to the area the system serves.

  8. #8
    Join Date
    Nov 2004
    Posts
    136
    Having 3 systems with what is essentially a common return is a problem and needs to be addressed.

    As for one return, or central return, it’s ok as long as the door to all the rooms are what is called “under cut” to allow air flow between the bottom of the door and the rug. You can also have transfer grilles installed from each room to the central return hallway. It’s not the best way to do it but we see it a lot and it’s allowed in this area.

    Find a good contractor to look over your floor plan and move the returns to their respective zones. Oh, and make sure the stats are located near the new returns

  9. #9
    Join Date
    Aug 2003
    Posts
    1,841
    Central return they do that to save money that is it.

  10. #10
    Join Date
    Nov 2004
    Posts
    136
    Originally posted by framehvac
    Central return they do that to save money that is it.

    I agree 100%!
    Like I said, It's not the best way to do it but it will work.

  11. #11
    Join Date
    Jun 2004
    Location
    4H: Hot, Humid Houston H.O.
    Posts
    3,304

    3M filters

    I am listening with care to what you are saying about 3M filters. It sounds like you more are less think they *are* defective in loading up more quickly than others do. OK, I accept what you say and won't even think of defending 3M unless you say something to the contrary. Thanks for the benefit of your experience and education.

    Best wishes -- P.Student


  12. #12

    HI VELOCITY

    In the Unico install manual they only have one central return. Is this not the way to do it? Should there be a return in each room? Or is it that because it is hi velocity only one central return is necessary.

  13. #13
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    We have a 25% Heating and Cooliing operating cost guarantee,or we(currently Carrier of Florida) pay the difference to the customer.This is replacing a 10SEER heat pump,with a 12 SEER heat pump,with Variable speed fan and Thermidistat or now Infinity.Based on heating and cooling costs ,being 46% of the total bill(fiqure from Progress Energy),it works out to about 11% of the total.

    Retired guy waits till near the end of the year,his saving are zero.So they go out on the 3th of the month,can't find a problem.

    Now he's retired ,not a lot to do,and this has been bothering him.He shows them,where he's been reading his own meter ,everyday,tracking the kw's used.Service mgr ,looks it over,if you multiply the daily kw's used,during the first few days of the month,times the days in the billin g cycle,he would have saved over the 25%.At the end of the month his kws per day was excessive.

    So they ask,what might he be doing on the first of the month?That's when he changes then filter,and you know,they found a 3M installed!

    Switched back to regular filter,no probelm.

    After this we tested a 3M in our Training Room,very little traffic,loaded up in seven days.

    p student,

    Sorry if I sounded harsh,but yes I hate those filters,other than that post ,just the 3m thing,you right on target and help out a lot of people.Thanks

Page 1 of 4 1234 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event