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Type: Posts; User: TMRCIN

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  1. Thread: Duct Sizes

    by TMRCIN
    Replies
    5
    Views
    2,230

    Duct sizing

    In order to know what size duct will go with a given CFM you will need to know what velocity you want to work with. For main trunk duct try to keep the velocity around 1000 to 1200 FPM. As you take...
  2. Replies
    4
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    1,027

    VAV

    You already have a very good idea of the problems that can be faced with a retrofit VAV system. Don't get me wrong it can be done but you will have to address all of the above. The speed drive is the...
  3. Replies
    31
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    2,482

    VVT

    If you use a reheat coil along with the VVT Damper the duct temp sensor will need to be relocated down stream from the coil so you can read duct temp. Then a minimum damper position of (1) is...
  4. Replies
    11
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    3,311

    Twin

    In a twinning configuration the return is very important. If one of the units is starved for air it will hit the high limit temp shutting it down and when the fan stops it will spin in reverse from...
  5. Replies
    5
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    596

    VVT

    System mode demand is by # of callers but can also be influenced by how far a zone is from set point. If you are having problems with this system you will need the literature to set it up properly....
  6. Replies
    31
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    2,482

    VVT

    Carrier is still making the VVT control system and is now in the Gen 3 version. I have found it to be a very good system if it is set up correctly. One of my accounts had 175 addresses on 35...
  7. Replies
    20
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    1,837

    This system would be very hard to control in the...

    This system would be very hard to control in the spring and fall when it may be summer on the south side and winter on the north side. The only way to save this would sup heat. If using VAV boxes the...
  8. Replies
    24
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    2,397

    I have toyed with the idea of using a Glycol...

    I have toyed with the idea of using a Glycol system using a water coil in the duct supplying the server room and a dry cooler outdoors to reject heat. This would isolate the room from unwanted...
  9. Thread: Fabric Ductwork

    by TMRCIN
    Replies
    28
    Views
    2,333

    Fabric Duct is cheaper and faster to install and...

    Fabric Duct is cheaper and faster to install and will blend well with open steel structure. Maintenance is a little bit of a problem. The fine screen used in air discharge will collect dirt and plug...
  10. Replies
    339
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    45,937

    In Cincinnati Ohio. Started in 1964 in a union...

    In Cincinnati Ohio. Started in 1964 in a union sheet metal shop. Got in as a 1st year apprentice in 66' took a 2 year vacation in the US Army 66' to 68' and back as a 1st year apprentice in 68'....
  11. Replies
    4
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    491

    It can be easier. The side you are looking at is...

    It can be easier. The side you are looking at is always the first number.
  12. Replies
    27
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    2,866

    jmiles when I switched to the service side it was...

    jmiles when I switched to the service side it was with the same company I was working for. In sheet metal I had experience in all the different phases of the trade. Started working in the fab shop of...
  13. Replies
    27
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    2,866

    Stay with Mechanical Equipment Service. It will...

    Stay with Mechanical Equipment Service. It will be a well rounded education and cover most all the trades. A good service man is a one call can do it all guy. I spent 22 years in union sheet metal...
  14. Replies
    19
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    1,468

    cjr7806 stick to the HVAC-R trade. When you get...

    cjr7806 stick to the HVAC-R trade. When you get in ask as many questions as the techs will tolerate. I spent 22 years in sheet metal union doing everything from shop, to air balance and finally...
  15. Thread: Carrier ccn

    by TMRCIN
    Replies
    9
    Views
    724

    Also on the vibrating damper.If after solving the...

    Also on the vibrating damper.If after solving the duct pressure the damper is still vibrating it may be out of adjustment. When it goes to the close position it will try to overdrive ( drive close...
  16. Thread: Carrier ccn

    by TMRCIN
    Replies
    9
    Views
    724

    If you check the duct static at the bypass and...

    If you check the duct static at the bypass and find it low you need to recalabrate the duct pressure sensor. If you find it won't recalabrate to the value in the duct it is toast. I have changed a...
  17. Replies
    12
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    1,113

    When the air exits the duct system thru a grill...

    When the air exits the duct system thru a grill or diffuser it is no longer effected by the static inside the duct.At that point it is just velocity. A vane anemometer or a valometer is just reading...
  18. Replies
    12
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    1,113

    If you were doing a duct traverse with a pitot...

    If you were doing a duct traverse with a pitot tube that formula would be true. The instrument would cancel out the duct static to read the velocity pressure thru a known area to arrive at CFM.
  19. Replies
    12
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    1,113

    The Alnor hood does not care what the duct static...

    The Alnor hood does not care what the duct static is it is only reading the velocity pressure thru the hood.
  20. Replies
    36
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    2,813

    You may want to take a look at all the linkage to...

    You may want to take a look at all the linkage to be sure some or all are not binding in the closed position. If the damper moves easily after the closed point a part of the system may be overdriving.
  21. Replies
    12
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    1,113

    If the floor tiles are the 2X2 perfs it should be...

    If the floor tiles are the 2X2 perfs it should be no problem.
  22. Replies
    1
    Views
    341

    That cylinder thing is a solenoid valve. When it...

    That cylinder thing is a solenoid valve. When it is energized (24V ac ) it opens to allow water flow. Check to see if it is getting voltage.
  23. Replies
    9
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    979

    If you think a 42X60 louver is huge why not go to...

    If you think a 42X60 louver is huge why not go to a makeup air fan that is ducted into the room. It can be adjusted to match the air flow of the exhaust.
  24. Thread: Cutting S Lock.

    by TMRCIN
    Replies
    39
    Views
    2,802

    When I worked in a general sheet metal shop we...

    When I worked in a general sheet metal shop we would use the red and greens to cut 16ga stainless and mild steel.
  25. Thread: Cutting S Lock.

    by TMRCIN
    Replies
    39
    Views
    2,802

    Remember what a hacksaw looks like? A little slow...

    Remember what a hacksaw looks like? A little slow but works fine.
  26. Replies
    13
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    1,785

    Check rotation. If someone has replaced the motor...

    Check rotation. If someone has replaced the motor they may not have checker it. I found a large swimming pool exhaust fan that had been running correctly for years suddenly reverse. Turned out the...
  27. I think we should revisit the cause of high...

    I think we should revisit the cause of high ozone. In my opinion it is low air flow thru the air cleaner due to the up sizing of the equipment and not upsizing the duct size for the higher air flow.
  28. Thread: Fan question

    by TMRCIN
    Replies
    21
    Views
    1,123

    A direct drive fan will slow down when resistance...

    A direct drive fan will slow down when resistance goes up. This is why you should never take an amp reading with the fan door off. A belt drive fan will run at the same speed no matter what the...
  29. Replies
    9
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    8,932

    Be sure to check the main duct at the plenum for...

    Be sure to check the main duct at the plenum for a balancing damper. Just does not seem right that this was not a problem last year but it is now.
  30. How is the return duct connected to the furnace?...

    How is the return duct connected to the furnace? Depending on the size of unit the manufacturer may require one side and bottom or both sides. If this is the case the limit may not be seeing enough...
  31. As usual the Maytag Man is correct about upsizing...

    As usual the Maytag Man is correct about upsizing the unit being part of the problem. The original duct was sized for 1400CFM and now you are trying to get 2000 CFM thru it. If the air cleaner was...
  32. With the stat in the off position the heating and...

    With the stat in the off position the heating and cooling are off. Note that with the stat in the off position and you turn the fan switch from auto to on the fan will run. If you do have a temp...
  33. Replies
    9
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    8,932

    The remote sensors is a very good idea. If you do...

    The remote sensors is a very good idea. If you do go this route be sure they do average.
  34. If your unit is in the attic and you do have a...

    If your unit is in the attic and you do have a temp sensitive fan control it can very easily see a higher return temp since most all duct work will leak.
  35. You must be very sensitive to changes in your...

    You must be very sensitive to changes in your environment. I suggest you look into adding some outside air to the system. Most all houses are short on ventilation air.If you are in the habit of...
  36. The compressor is controlled by the thermostat....

    The compressor is controlled by the thermostat. If you have a temperature sensitive fan control it is sensing air temp thru the furnace.
  37. Replies
    9
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    8,932

    The above are correct in regards to the fan ( ON...

    The above are correct in regards to the fan ( ON ) this will even out room to room temp but it will only be a compromise. You have the typical two story problem, can't get enough air to the 2nd...
  38. Reply

    I have posted on your problem but fail to see it on my list. Do you see it? TMRCIN
  39. Ozone ?

    This new unit has a two speed fan and the original post stated the installer set it to auto. If the system comes on in heat mode it would be on low speed. The electronic air cleaner is sensitive to...
  40. Fan with a mind of its own

    On some older units with temperature sensitive fan controls it may be set to low. I have seen a piolet produce enough heat to activate these fan controls.In the good old days when energy was cheep...
  41. Replies
    49
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    6,365

    Thanks to all

    I would like to thank everyone for the great information received on the Pulse problem. It is obvious there are a lot of talented technical people on this site and I do expect to gain the needed...
  42. Replies
    49
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    6,365

    I am confused!

    I thought this site was for the exchange information and ideas.Now Senior Tech tells me that technical matters can not be discussed here. Do you think I am a DIY looking to be bailed out of a...
  43. Replies
    49
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    6,365

    Lennox

    I was a sheet metal worker for 22 years with 12 years of that in air balance and system design and service. In 88' I switched to HVAC service.I installed this furnace in 86' for a neighbor and have...
  44. Replies
    49
    Views
    6,365

    Lennox Pulse Not firing

    Hello all. I have been working on a Lennox Pulse furnace that will not fire off. The ignition module is ok and sparking the plug. The flame sensor is new. I have gas down stream from the gas valve...
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