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  1. #1
    Join Date
    Jun 2006
    Posts
    110
    I'm having a Bryant 355AV 90I furnace installed. It has a Variable Speed blower. I also included an Electronic Air cleaner.

    The object is to be able to run the system in "fan only" mode 24X7 so that the air in house is constantly cycled through the EAC, the "theory" being I scrub my air all the time and life is great.

    Problem: The licensed HVAC guy installing the unit has never heard of such a theory and therefore didn't have a clue as to how to run the fan only nor how to control the fan speed!

    Anybody able to shed some light on the subject of fan speed control with a Bryant 355AAV furnace and Honeywell FocusPro thermostat?

    Research on my part appeared to indicate they were supposed to have given me an Evolution thermostat which would do what is needed, but they gave my a Honeywell FocusPro (appears to be a decent unit) which doesn't have such a feature. They call Tech Support and get feedback that if I simply cycle the system Fan from "Auto" to "ON" repeatedly then the fan speed cycles through the speeds.

    We tried it. It works....sort of. Problem being that we can't really tell what the speeds are, as in sometimes 5 Auto/On cycles brings it all the way from lowest speed to highest speed and back to lowest speed. Another time after 15 Auto/On cycles it was still not back to lowest speed (as though it was still increasing very slightly).

    Long story.

    Anybody able to shed some light on the subject of fan speed control with a Bryant 355AAV furnace and Honeywell FocusPro thermostat?

    -dhh


  2. #2
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    If the furnace can use the Evolution Control(Carrier is the Infinity Control),that's what I'd have them install.

    It's the best control for other reasons as well.

    You can easily set the off cycle fan speed ,right at the control/stat.

  3. #3
    Join Date
    Jun 2006
    Posts
    110
    RE: Having them install the Evolution Control -- Yeah, that is sadly going to be an "argument" for me as the contractor now doubt will not want to be "giving away" anything they feel they didn't specifically promise me. The contract simply specifies "a thermostat" whereas it was my very obvious assumption that because the Evolution Control is listed as a "Feature" that accompanies the furnace that it is what I would get. So, again, that is likely going to be a losing argument on my part as the contractor pulls the usual game of digging in their heels and waiting for me to just give up and give them their money.

    RE: How to control the fan speed -- the system was pitched to me as one which I could control the fan speed on when in fan only mode, therefore it is again a logical assumption that I won't have to crawl up into the attic, take the cover off the furnace circuitry, and twidel around with jumpers/switch settings each time I want to increase/decrease the fan speed.

    Their does appear to be an "undocumented feature" of the variable speed fan control such that cycling the fan on/off makes it increase speed. That's what I'm looking for more information on, as I am sadly certain that I'll lose any argument about having to have the Evolution control (unless I pay another $700 or so for it).

  4. #4
    Join Date
    May 2004
    Posts
    1,462
    The fan control is not "undocumented." The contractor should know how to do this or he should not be selling the furnace. You can not "take the cover off and set this." You have been told correctly about how to change speeds.

    Toggling the fan switch from Auto to On to Auto to On in 3 seconds will toggle the fan to different speeds. Once you have it set to the speed you want you do not have to do this any more. In other words if you are satisfied with the speed and then turn the fan back to Auto for anything over 3 seconds, the next time you turn it back to On it will remember and go back to the same speed you had last time. There is no indicator of what this speed is, only trial and error checking air flow. If you are constantly toggling the switch, you are probably toggling faster than the fan can change and therefore do not give it time to adjust.

    This furnace will always run the fastest fan speed called for, so if you have another call of some type it will run that speed and not the constanst fan speed. In other words you can not lock it at a certain speed. Word to the wise, get the Evolution control or you will never have proper control or be satisfied. It offers so many other options that will make you happy. See if you can not negotiate the price if you return the Vision Pro for the Evolution.
    If all else fails....Try reading the directions!

    Tell it like it is and let the chips fall where they may.

    Any views or opinions stated here are strictly my own.


  5. #5
    Join Date
    Jul 2004
    Location
    Denton Texas
    Posts
    20
    There is another way…

    But let me shed some light on the operation of that particular furnace. It is in my opinion the best furnace on the market. And if you want great indoor air quality you made the right choice. The variable speed blower motor can run all day and consume very little electricity.

    The fan plus feature your talking about was designed to allow some flexibility for constant fan, the only drawback is that since the fan motor is completely variable, toggling the fan switch could step you through anywhere from 4 to 14 different fan speeds (depending on the full model number)

    If you don’t want to upgrade to the evolution control this is how I would do it.

    Ask your contractor to do the following

    First disconnect power to the furnace to reset the PC board this way what ever fan speed it may be currently set to is erased from the boards EPROM (erasable programmable on-board memory) chip.

    Second find the recommended airflow for the electronic air cleaner. It’s not recommended to drop below this value or you might notice an increased ozone smell from the cleaner.

    The furnace installation manual has a chart and instructions on how to set the desired constant fan CFM (cubic feet per minute) of air with three dip switches found on the board. Pick a value that’s comfortable for you. And meets the CFM requirement for the air cleaner and is not excessively noisy

    Then take the thermostats fan switch and put it in the on position and leave it there.

    The fan will stay on the selected CFM when the heater or AC is not running

    The fan speed will only change when heating or cooling comes on. And you can have clean air
    “The definition of Insanity is doing things the exact same way but expecting different results.” James P. Curley

  6. #6
    Join Date
    Jun 2006
    Posts
    110
    Now there's some really useful feedback, thanks! It is a luxury to get back more good information than one can keep up with.

    Regarding the minimum CFM for the Air Cleaner, I've been looking and looking through the manual for the unit and have yet to find anything about that. I'll look some more. The tech installing the system only says that "I want as much air blowing through the AEC as I can possibly get!". Then again, he acted truly surprised when I told him I wanted to run the system in fan only mode 24X7 (unless heating or cooling).

    Regarding the toggling between Auto/On to change speeds: It was quite interesting that when the tech was doing the toggling he only toggled 4-5 times to go from min to max to min. Then when I tried we gave up after 15 toggles cause the fan seemed to still be slowly getting faster and faster. Is there a logical explanation for this?

    Regarding the Evolution Control board: I really would like to understand what the Evolution Control board offers me that the one I have (FocusPro TH6110D) does not. I've begun conversation with the dealer/contractor regarding why they seem to have sold me an Evolution but delivered a FocusPro and would like to know specifically what I might be arguing for. No sense my arguing for something I don't really want/need but then again no sense not arguing for something I really do want/need. So, can somebody offer me details on what the Evolution will do for me so I can compare/contract that with other thermostats?

    Thanks!


  7. #7
    Join Date
    Jul 2004
    Location
    Denton Texas
    Posts
    20
    Glad it was helpful

    If you read through the installation manual of the EAC the minimum CFM may be listed a couple of different way sometimes a number in a table or as a line on a graph. Some EAC’S include an airflow sensor designed to shut it off if the airflow drops to low. You might want to look for a section on the air proving switch it might say at what CFM it cuts off. As long as you stay above that value it should run fine.

    As for the fan seeming to continually get faster each time the switch is toggled, they way the furnace works has a lot to do with the size of the blower motor, the factory has a few different horsepower motors that can produce multiple speeds. I know that some have up to 14 different speed selections but it can be very hard to tell exactly when the fan speed changes without measuring the face velocity of the air leaving the register. It may seem like 15 or 17 because the faster it runs the less of a change there is between each speed. In other words the faster it runs the lower the RPM difference between the next speed.

    I don’t know much about the focus pro stat but I know the Evolution stat is top notch in my book. It has very large display that is backlit and easy to use buttons.

    You can go on line to http://www.bryant.com/interactive/evolution.shtml to try an on line flash demo.

    Some of the nice features are that you have a fan button on the upper right that instead of selecting on or auto you can select auto, low, med & high you wont have to toggle the button 17 times to get a good speed.

    An outdoor air sensor can be connected so it can read the outside air temp

    It can be setup to be seven day programmable with multiple time periods per day.

    It has a smart recovery feature that continually tracks how long it takes to bring your home up to temperature and brings the equipment on at the right time each morning so that the house is at set point as soon as you get out of bed. And as the weather changes it adjusts how soon it comes on to run as efficiently as possible.

    It also has maintenance reminders that will automatically let you know when to change or clean your filter, humidifier, UV lights ect…

    The control and furnace are so smart that they communicate back and forth so that the control can show what RPM the motor is turning at, what the system static pressure is, and how much CFM the furnace is putting out…

    However I digress…

    Try the online tutorial and check Bryant’s web site and I think you’ll find a wealth of good information.
    “The definition of Insanity is doing things the exact same way but expecting different results.” James P. Curley

  8. #8
    Join Date
    Dec 2005
    Location
    NOrthern Ohio
    Posts
    37

  9. #9
    Join Date
    Dec 2005
    Location
    NOrthern Ohio
    Posts
    37
    sorry for the duplicate link from the previous post. tech support101 posted about the same time I did. Great info tech support. If you can work it out with the contractor, you would be pleased with the Evolution thermostat.

  10. #10
    Join Date
    Aug 2004
    Location
    Los Angeles, CALIFA
    Posts
    1,134
    Yeah Tech Support 101 is correct. Considering he taught me everything I know.
    Do as I say, not as I do

  11. #11
    Join Date
    Jul 2004
    Location
    Denton Texas
    Posts
    20

    Talking

    Well done my young apprentice… HA HA HA HA
    “The definition of Insanity is doing things the exact same way but expecting different results.” James P. Curley

  12. #12
    Join Date
    Aug 2004
    Location
    Los Angeles, CALIFA
    Posts
    1,134
    Originally posted by tech support 101
    Well done my young apprentice… HA HA HA HA
    Lets See If we Can Bring Up Your Post count. Gezz, 9 Post since July of 2004. You suck diddily-uk. Now I have a question for you. I remember you telling me that if I jumper R & C I can get my system to run better correct?
    Do as I say, not as I do

  13. #13
    Join Date
    Jul 2004
    Location
    Denton Texas
    Posts
    20

    Smile

    sorry i have been very busy teaching someone else all i know.

    took a lot longerthan i thought.

    plus i have to train my new apprentice my son...your nephew.

    and you know how much fun he is



    PS my count is now up to 10


    only if you lick your hands real good and take off your shoes first.

    [Edited by tech support 101 on 09-08-2006 at 07:25 PM]
    “The definition of Insanity is doing things the exact same way but expecting different results.” James P. Curley

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