'Fan On' Speed for Trane AH


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Old 06-15-06, 11:32 PM
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'Fan On' Speed for Trane AH

I have a Trane Variable Speed Air Handler (TWE049E13FB2). The installation guide clearly describes how to set airflow for heating mode and cooling mode. However, I like the continually run the fan to even out air temperature in the house. The fan speed is very low when not heating/cooling.

Is there an adjustment to change this fan speed?
 
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Old 06-16-06, 05:55 PM
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I think that when it is in enhanced mode the fan only runs at 50%, you can try changing your dip switches to see.
 
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Old 06-16-06, 10:28 PM
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I'm not in enhanced mode. Here are how my dip switches are set:

Switches 1-4: (Cooling Airflow) is set to 400 CFM/Ton.
Switches 5-6: (Cooling off delay options) is set to 1.5 minutes/100%.
Switches 7-8: (Auxillary Heat) is set to 1400 CFM as required by my supplementary eleictric heaters.

Any other thoughts?
 
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Old 06-17-06, 11:32 AM
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Wink

Did the installer tie in a humidistat there on that V/S blower . Tied from R to BK in air handler. Now that would turn the blower speed down on you. When the humidity is high for what its set at. Id check that out first.

ED
 
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Old 06-17-06, 05:17 PM
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There is no humidistat. R and BK are tied together.

Even so, my understanding is that the humidistat only affects the fan speed while cooling. I'm seeing a low fan speed when both cooling and heating are off (and have been off for a long time).

Any other ideas?

Thanks,
Cliff
 
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Old 07-26-07, 10:47 AM
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Originally Posted by CliffV View Post
I have a Trane Variable Speed Air Handler (TWE049E13FB2). The installation guide clearly describes how to set airflow for heating mode and cooling mode. However, I like the continually run the fan to even out air temperature in the house. The fan speed is very low when not heating/cooling.

Is there an adjustment to change this fan speed?
I am also trying to determine the wiring (With or W/O a relay) diagram to boost the variable speed fan in my Trane XV90 to engage high speed while the thermostat fan is "ON" and the compressor is not engaged. Any info?
 
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Old 07-26-07, 11:49 AM
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Since I first posted this thread, my installer called Trane to get an answer to my original question. During "Fan On", the fan runs at 50% of whatever the maximum speed of the fan is. There is no mechanism to change this.
 
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Old 07-26-07, 12:05 PM
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That is incorrect. There is a modification that will allow the VS fan to run on high speed at all times while in the AC mode and with the fan "ON" mode. It would have no affect on the Heat settings. I know that it has been done. I simply am unable to put my hands on the schematic. I have posted an inquiry under the Air Conditioning forum.

I also challenge the 50% claim while the compressor is off and the fan is in the "ON" mode. At that time the fan is running well below 50%.
 
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Old 07-26-07, 02:18 PM
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On the furnace / air handler board you should have two wires on the "Y2" connection, assuming a two-stage cooling system. One of these wires will be coming from the thermostat and the other will go to the outside unit. Remove both of these wires and wire nut them together. Run a jumper from "R" to "Y2" and the blower will run continuously at the second-stage cooling speed. The A/C will run according to the thermostat settings.

If you want the blower to be controlled by the "fan auto-on" switch on the thermostat then move the green lead on the control board to the "Y2" connection without adding the jumper.
 
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Old 07-26-07, 05:15 PM
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Yes, there is a way to bring up the speed on the air handler..

You want the blower running 80% of your cooling speed, or 100%?

Why do you want higher speed?

Ideal behind the variable speed system is to slowly move air around for comfort, and quietness. I love how my fan run slows in the winter.. I run AUTO in the summer.
 
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Old 07-27-07, 07:16 AM
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I understand the reason for slowing the air to remove humidity. However, during the time period while the compressor is not engaged I need to circulate more air on the second floor or it becomes stale. The real fix is to add insulation and install a second system on the second floor of most recently constructed homes with an adequate number of true ducted returns as opposed to the leaking stud-space returns contractors are so fond of.

Having said that, my previous 18 year old York system had a four speed blower motor that was easily wired on high speed during the summer. While having a slightly higher level of humidity on the 2nd floor it kept the air fresher while the fan was left in the "ON" mode. I need to accomplish this with the VS blower in the XV90.

Thanks for the feedback.
 
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Old 10-28-08, 07:38 PM
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80% Would Be Great

80% would be great for me. I want it for the same reason as cliff--the top floor of my house is colder than the main floor and I'd like to even things out by moving more air around.

If you have a way to do it, I'd love to hear it.

Originally Posted by Jay11J View Post
Yes, there is a way to bring up the speed on the air handler..

You want the blower running 80% of your cooling speed, or 100%?

Why do you want higher speed?
 
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Old 10-31-08, 09:58 AM
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Originally Posted by clarku View Post
80% would be great for me. I want it for the same reason as cliff--the top floor of my house is colder than the main floor and I'd like to even things out by moving more air around. If you have a way to do it, I'd love to hear it.
Take a look at the message from "furd". That post gives you two more options on how to adjust the fan speed.

I did NOT end up making those changes. Here's why. The West face of my house is all glass. That means that there is a lot of sun entering the house during the afternoon. The main area of the house has a cathedral ceiling and an open loft. In the afternoon, the loft was getting unbearably hot. The problem turned out that there was only one small A/C vent in the loft and that the air intake was in the basement. My installer added an air intake to high up near the cathedral ceiling and another large air output vent blowing into the loft. With these changes, I didn't need to change the fan speed.

In the cooling season, the new air intake sucks warm air from the ceiling, cools it, and distributes it around the house. The net is less warm air near the ceiling (and thus in the loft). The new air output supplies more cold air in the loft. In the cooling season, I manually close the air outputs in the basement. Even then, the basement borders on too cool for my taste.

In the heating season, the new air intake again sucks warm air from the ceiling, heats it more, and distributes it around the house. The net is more efficient heating. I actually then manually close the new air output vent in the loft. Since the loft is so close to the ceiling, it simply doesn't need any more heat in the winter. In both the heating and cooling season, I keep the fan "on" during the day to keep the temperature as even as possible throughout the house.

I suspect that the A/C installer mis-estimated the cooling needs of my house. On a hot summer day, the sun blasts though the West facing windows. During the afternoon, the main part of the house will rise to 3 degrees over where the thermostat is set. (The loft will rise to 5 degrees over where the thermostat is set.) But this situation is much better than when I started. Cheers, Cliff
 
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Old 10-31-08, 12:34 PM
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There is another way to wire this, but I can not find it back.. I think I had it on my hard drive, and the hard drive crashed on us last winter.

I am still looking around to find it.
 
 

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