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  1. #1
    Hello everyone.
    this is a reposting. If anyone has answers it would be greatly appreciated.

    I wish I had found this site prior to having my a/c system and new heater installed. There really is wealth of information on this site thanks to all of you.

    My question is this, I had the following installed: a 3.5 ton American standard Allegiance 14 model #2A7A4042 for the first floor and a 3 ton model # 2A7A4036 for the upstairs. These were paired with american standard variable speed air handlers model # 2/4TEE3F40A with honeywell f100 media filters. Each system has two zones.

    For the heat and hot water a burnham v8 series v86 oil fired boiler was installed.

    The first floor system was also fitted with an EWC model S2020 whole house humidifier with its own humidastat. the one that came with humidifier.

    Four white rodgers single stage thermostats were installed which are the 80 series. Model #1f80-361.

    I have questioned weather the variable speed air handlers
    are doing what they are supposed to do. (change speeds)

    After reading one of the posts here by wyounger (quoted below)I question weather the contracter installed the proper thermostats to take full advantage of these air handlers.

    Which thermostats are you refering to in that post that will comunicate with the air handlers? Are the white rodgers thermostats I have adequate?
    Is there a way for the humidistat for the humidifier to be eliminated and have the thermistat for the A/C/ heat control that function also? Which thermostats would do this?

    The variable speed air handlers have dip switches on the circuit board (8 of them) which can be set in different combinations for optimum performance. which settings would you recommend?


    Lastly I read somewhere that the blowers on the air handlers have adjustments so they can be matched to the size of the condensors. What settings should those be and how is this done?

    I asked the contracter if these were all set up and he said yes, but after installing the system he just always seems to be in a rush to leave so I dont think he took the time to set them up properly.

    Sorry this is so long. Im learning. Thanks in addvance for the help.


    quote:
    --------------------------------------------------------------------------------
    Originally posted by wyounger
    [
    "The VisionPro's only trick for humidity control is that if humidity is too high when there's no demand for cooling, it can start the AC up and do some overcooling to help compensate.

    Many other thermostats in the same price range can do that, but can also send a signal to a variable speed furnace/air handler to slow down the blower as needed anytime the AC is running. By running the blower more slowly in cooling mode, the system dehumidifies more than usual and cools less than usual. It will do that as needed during a call for cooling, but can also use this strategy in conjunction with overcooling. That way the thermostat has some additional control over humidity beyond just overcooling, and if it does have to overcool, it can adjust the blower speed to try to maximize dehumidification and minimize how much it has to cool the place beyond your cooling setpoint.

  2. #2
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,086
    Best bet is a Vision Pro IAQ. It will control a humidifier plus interface with the variable speed blower in the summer to slow it if the indoor humidity is high.

    The dealer should set up the DIP switches properly when he installs the equipment. If you have doubts, have him show you the manual and prove that he did it right!

  3. #3
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,913
    Since the thermostats are wired to the zone panel, they can't communicate with the furnace.

    What zoning system do you have. (brand)
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  4. #4
    I have EWC model st2e zoning system?

    I dont have a furnance I have aon oil burner with a store all tank for hot water.

    A heating coil was installed in the ductwork above the air handler.

    Sorry if I dont use the proper terminology.

    Thanks for the reply I appreciate it.

  5. #5
    Join Date
    Aug 2004
    Location
    North Richland Hills, Texas
    Posts
    14,914
    The EWC ST zone control can only control one stage of cooling and one stage of heating. If set up properly, the CFM through the air handler should stay constant during a call for heating or a call for cooling, regardless of if one or both zones are calling. What is done with all that air depends on how the duct system is designed.

    Any 1h/1c thermostat will work with that panel, and there really isn't anything operationally that can be gained by switching to different thermostats.

    As for the setup of the zone control and the air handler, and the control wiring, thats a bit more detailed than we can get into here, but it at least sounds like what you have should work.
    That zone control is a bit more limited than what I like to use though. Usually I use the EWC BMPlus or UZC zone controls.

    With your type of heating system you could have true 2 stage heating with a different EWC zone control using the same thermostats.

    There are a lot of options for how the system can be controlled using EWC zone controls.

    With the UZC, BMPlus or NCM controls you could have 2 stages of heat and have each zone able to call 2nd stage by itself if you have 2 stage thermostats in the zones.


    With a UZC control you could even have electric heat stips installed in the air handler so you have 2 stages of heat using the hot water coil and a 3rd stage in case the hot water system isn't keeping up, or something goes wrong with it. With just a little imagination, the system could have 4 stages of heat using a UZC control, hehe.

    I'll stop there.

    [Edited by mark beiser on 10-28-2006 at 11:22 PM]
    If more government is the answer, then it's a really stupid question.

  6. #6
    thanks for the feed back.

    But my main concern is this.
    one zone is for one room above a garage. This was seperatley zoned for the obvious. it is colder in the winter and hotter in the summer. so therefore a seperate zone would give better control of temp.

    after system was installed to much pressure was being delivered to that zone when the other zone closed. so a bypass dampner was installed. (I still think there is to much pressure)

    After thinking about what was done I question whether the variable speed air handler is set up properly. Shouldnt it sense the additional pressure and ramp down automatically?

    Secondly I question wether it changing speeds at all. How do you test this? I would expect (and thought) that the air handler could be set up at slower speed (or change its speed automatically) to stay on for a longer period of time before shutting off.

    Hope this makes sense
    Thanks again


  7. #7
    Oh I forgot to ask.

    Mark when you say

    "With your type of heating system you could have true 2 stage heating with a different EWC zone control using the same thermostats.

    With the UZC, BMPlus or NCM controls you could have 2 stages of heat and have each zone able to call 2nd stage by itself if you have 2 stage thermostats in the zones.

    What does that mean in laymans terms. Sorry for my ignorance. The installer is supposed to come back this week and I would like to get this right?

    Thanks again

  8. #8
    Join Date
    Aug 2004
    Location
    North Richland Hills, Texas
    Posts
    14,914
    The air handler will maintain a constant quantity of airflow through the unit, so the blower will actually speed up when one of the zones close.

    If you want the air handler to run at different airflows based on zone calls in the heating mode, it will have to be set up for 2 stage heating using a different zone control.

    With your current equipment you can only have 1 stage of cooling airflow, unless you change to the Allegance16 or 18 outdoor units, wich would be very expensive.

    The settings for the bypass damper can be adjusted, and maybe the duct and vent sizes in the smaller zone can be increased to reduce air noise. The cooling equipment requires a certain quantity of airflow through the coil to work correctly though.

    The best option, that doesn't involve changing to different controls and/or equipment, may be to have your contractor set the zone damper for the larger zone so its closed position is still open a little. This would dump some of the air to the larger zone when only the smaller zone is calling.
    A service tech that understands the equipment, and has a manometer and a thermometer, could get it set up to work very nicely with the equipment you have now.
    If more government is the answer, then it's a really stupid question.

  9. #9
    Join Date
    Aug 2004
    Location
    North Richland Hills, Texas
    Posts
    14,914
    Originally posted by bournazos
    Oh I forgot to ask.

    Mark when you say

    "With your type of heating system you could have true 2 stage heating with a different EWC zone control using the same thermostats.

    With the UZC, BMPlus or NCM controls you could have 2 stages of heat and have each zone able to call 2nd stage by itself if you have 2 stage thermostats in the zones.

    What does that mean in laymans terms. Sorry for my ignorance. The installer is supposed to come back this week and I would like to get this right?

    Thanks again
    It means you could have 2 levels of airflow/heat available in the heating mode, even with only one zone calling.

    You would need a different zone control that can run 2 stage heat.
    You would also need 2 stage thermostats in the zones you want to be able to call 2nd stage when only that zone is calling for heat.
    You would also need service person that understands how to set it up, wich may be the main stumbling block.
    If more government is the answer, then it's a really stupid question.

  10. #10
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,913
    Or, in other words.
    You current system set up, with the controls you hve, is doing what it is suppose to do.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  11. #11
    thanks mark

    I appreciate your time.

    So if I understand correctly, for AC i need to maintain a specific amount of air flow through the cooling coil so this cannot be set up for two stage cooling unless I have a 2 stage condensor.

    For heat however I can set it up for two stage because the heat coil does not require a certain amount of air flow.

    Just as a side note I read that the Allegiance 14 has a two speed fan motor. It doesnt say 2 stage only 2 speed fan motor. I cant find where I read that I will search for it and post the link.

    Thanks again

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