White Rodgers Thermostat 1F95-1291
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  1. #1
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    Moore, Oklahoma, United States
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    White Rodgers Thermostat 1F95-1291

    Has anybody installed or used one of these? Seems like an excellent design and does just about everything for a reasonable price.

  2. #2
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    Tampa, Florida
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    Highly recommend

    We've been using them as much as possible for the past 2 years. Both commercial & resi. The two biggest features we use it for: a real Dehumidifiy terminal and supports external sensors for averaging/remote control. You can even weight the sensors by time of day.

    Since we started using them, I've not installed a Honeywell VP. I've even replaced a few of the VP8321 with these because of the real dehumidify terminal. And of course, cost. The VP IAQ can do more, but we've not needed it.

    Staging on it is good, temp control is good despite it appearing to use straight temperature differential vs. Honeywell's Proportional + Integral algorithm. Its staging appears to be P+I if you set staging to "slow", differential if set to "fast".

    A few minor cautions: Remote sensors ONLY work if thermostat has a return wire to Common. Sensors run on 24vAC. It's in the manual somewhere, but I've had techs miss that point.

    Make sure you mount it at or below the eye level of the customer -- viewing angle from below is minimal with the backlight on. Since the backlight is a "pretty blue" (as it was described to me) you'll probably have it lit continuously.

    And...we had one callback on one. Had one on a barrier island (think very flaky power) suddenly stopped working after 6 months. Pulled the stat off the wall, pull the batteries and put it back together. No issues since then, but still a callback. If it acts up again I'll add a larger transformer or put small cap on the transformer to smooth out power fluctuations. Ironically, we had another customer in the same building with the same stat and theirs didn't act up. Contrasting this to our HW VP experience, we had 2 VPs with defective touchscreens after 12 months.

  3. #3
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    "Cool Savings" feature

    I forgot to post about the "Cool Savings" feature that some of the WR stats have. The manual isn't real clear on this, so I pulled the patent (attached). This feature can be enabled/disabled and you can control just how far it'll offset.

    The goal:
    The longer an AC runs, the more humidity it pulls out. Given this, the less humidity in the air, warmer temperatures will feel more comfortable and in some cases running the AC further will make occupants feel uncomfortably cold. Therefore, if you slightly raise the temperature on long cycles, comfort can be increased and energy will be saved.

    The details:
    The stat measures temperature & setpoint in 1/16th of a degree.

    If enabled (as it works on the 1F95-1291, the patent seems to be slightly different):
    After 20 mins of runtime, for every 2 additional minutes of runtime the thermostat lowers the measured temperature (including display) by 1/16th of a degree until setpoint is satisfied or it reaches the installer-defined offset limit (1-6F).

    When the setpoint is satisfied, this offset is kept but paused. When another call for cooling starts, the stat maintains the offset but waits for another 20 mins of runtime, then starts increasing 1/16th every 2 mins again. If the compressor manages to stay off for 20 mins, the reverse starts happening -- offset is decreased by 1/16th every 2 minutes.

    So, if the setpoint is 76F, room is 77.5F, and AC runs for 44 mins to satisfy the setpoint. At the end of the 44 min run, the thermostat will have subtracted 1.5 degrees from the measured temperature and would show 76). Keep in mind, it's still 77.5F in there, but as far as the stat sees and what the user sees on the display, it's 76F. BUT, since the AC's been pulling humidity for the past 44 mins, it feels comfortable.

    The stat shows "Cool Savings" on the screen if this feature is enabled. "Cool Savings" will flash slowly if an offset is active.

    We use this in most of our commercial environments and it seems to work well. No tenant complaints after a year. This also seems to fix many of the temperature battles in office spaces where some people are polar bears and others get chilled easily. Since it also adjusts the display, the accountant-types are satisfied because the number on the screen is the number they want to see.

    I don't see as much need for this feature if you're using the stat's dehumidify output, but it's one more tool available to save energy.
    Attached Images Attached Images

  4. #4
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    I'm glad you explained the features of the unit, those were the ones I was particularly interested in. It appears the thermostat could be set 75 or so and let the thermostat determine the best comfort level. If humid it looks like it can reduce the temp down to 72 to dehumidify and the thermostat could raise the temp to 80 if the system is running a lot. Automatic blower speed control is just icing on the cake. Very ingenious system that seems to focus on overall comfort vs. just temperature control. The coolest thing is it works with my "low tech" existing equipment, good comfort control until my system dies and I can justify upgrading to a VS system.

    If the system had been off all day and the humidity/temperature were both above setpoint does the thermostat use low speed to take care of the dehumidification before satisfying the temperature? Or is it smart enough to know "it's hot in here, blower full speed ahead" then work on the humidity once the temperature is satisfied? Can the "2nd stage output" be used for force high speed blower operation?

  5. #5
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    Quote Originally Posted by 54regcab View Post
    If the system had been off all day and the humidity/temperature were both above setpoint does the thermostat use low speed to take care of the dehumidification before satisfying the temperature? Or is it smart enough to know "it's hot in here, blower full speed ahead" then work on the humidity once the temperature is satisfied? Can the "2nd stage output" be used for force high speed blower operation?
    It will indeed do what you're asking for. By default, if you're just using a single relay, it's going to "focus" on dehumidifying over everything else since that relay solely reacts to if humidity is above or below the humidity setpoint. It's actually "dumb" in this sense. If you add a 2nd relay, you can have 2nd stage cooling bypass the dehumidify terminal. In this way, it'll work more like your car's air con does -- cool off quickly, then worry about humidity later. The stat also supports independent (separate from cooling/heating calls) dehumidifier control via the humidify terminal, so you can use one of these to run a whole-house dehumidifier as well.

    I'd love to get into more detail on the wiring of that, but I think that's about as far as the mods will allow. It should be enough for your HVAC contractor to follow.

  6. #6
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    Since the "Stage 2" is a "high" output and the dehumidify is a "low" output could both connections simply feed the same relay? If either the humidity was good or it was hot enough to trigger the 2nd stage the relay would get a "high" forcing the 2nd blower speed. Does the thermostat internally use physical relays for the output terminals or is it done with electronics? I see it's millivolt compatible so I'm assuming there is at least one physical relay in there. I've always liked the micro relays over the transistor/triac controlled outputs, they seem to hold up better over time.

  7. #7
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    Can't answer that here -- forum mods strictly frown upon DIY. And for something like this, I'd agree with them. These relays will be switching high voltage. Let your HVAC contractor deal with it.

  8. #8
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    Quote Originally Posted by tpa-fl View Post
    Can't answer that here -- forum mods strictly frown upon DIY. And for something like this, I'd agree with them. These relays will be switching high voltage. Let your HVAC contractor deal with it.
    I just wanted to be sure it was installed right. Some contractors even bother to change the fan speed from the default settings unless they get a compliant from the customer or the unit clearly is not working correctly. This thermostat is unique and not all contractors may be familiar with it's setup. Any things I should look for in a contractor to be sure get one that will get it right? Most contractors are listed by equipment brand, but I haven't seen a way to see who is who when it comes to thermostat brand.

  9. #9
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    So, to be clear, using this thermstat with a psc blower requires a series of relays, and freeze stat?

    Jerry Rigger deluxe, frozen coils suck, wrong blower cfm, breakin it up, right about summer time (summer time!!!!).

    Brooks and Dunn - Hillbilly deluxe


    It's gonna be cheaper for the customer to wait for the furnace to die, and go with the varible speed, than the ammount of time + extra cost involved in rigging that abortion.
    "Better tell the sandman to stay away, because we're gonna be workin on this one all night."

    "Dude, you need more than 2 wires to a condenser to run a 2 stage heatpump."

    "Just get it done son."

    Dad adjusted

  10. #10
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    I didn't think hooking up one SPDT relay and possibly a freeze stat would be that difficult for a professional HVAC technician. I can understand not wanting to "homebrew" a humidity control system, but apparently the thermostat manufacturer feels like it's something that's not too difficult to do. I just need to find somebody with in depth knowledge of this particular thermostat that's willing to try it.

  11. #11
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    Quote Originally Posted by 54regcab View Post
    I didn't think hooking up one SPDT relay and possibly a freeze stat would be that difficult for a professional HVAC technician. I can understand not wanting to "homebrew" a humidity control system, but apparently the thermostat manufacturer feels like it's something that's not too difficult to do. I just need to find somebody with in depth knowledge of this particular thermostat that's willing to try it.
    "willing to try it" means experimenting on your system.

    Again:

    Wait untill you have your furnace changed out. When you do, get variable speed.

    Your going to spend time finding a contractor to do this. Then your going to have to pay this contractor an hourly wage, "trying" to rig this together. Cost of labor + parts is going to cost you more money than you having this correctly done. I'm not suggesting you change your furnace. I'm suggesting that the cost of "upgrading" to a variable speed motor when changing the furnace, is going to be cheaper than rigging this stat.

    If you do have this setup installed, and your furnace later dies and you get a new variable speed, guess who gets to pay to revert the system back to the way it should be?

    I know exactly what tpa-fl is suggesting. What he's not telling you, is the reason for the freeze stat, is because the coil will have a tendancy to fail with his setup.

    Also something to remember, the ONLY person who is saying this is possible, is not a professional member, and should not be posting advice.
    "Better tell the sandman to stay away, because we're gonna be workin on this one all night."

    "Dude, you need more than 2 wires to a condenser to run a 2 stage heatpump."

    "Just get it done son."

    Dad adjusted

  12. #12
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    Do typical VS systems have a dehumidify input that lowers blower speed or do they need a communicating thermostat to achieve this function? Do VS systems dynamically adjust blower speed to achieve required humidity level? Are VS systems something advanced knowledge is required to set up or can most HVAC contractors do it correctly?

    I see 400cfm/ton being used as the "standard", however it seems like optimum blower speed depends a lot on the humidity level in the home. Dynamically setting blower speed to maintain the optimum sensible/latent ratio seems like a good way to lower power bills w/o giving up comfort.

  13. #13
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    Quote Originally Posted by 54regcab View Post
    Do typical VS systems have a dehumidify input that lowers blower speed or do they need a communicating thermostat to achieve this function? Do VS systems dynamically adjust blower speed to achieve required humidity level? Are VS systems something advanced knowledge is required to set up or can most HVAC contractors do it correctly?

    I see 400cfm/ton being used as the "standard", however it seems like optimum blower speed depends a lot on the humidity level in the home. Dynamically setting blower speed to maintain the optimum sensible/latent ratio seems like a good way to lower power bills w/o giving up comfort.
    Goodman variable speed units are SPECIFICALLY setup to accept dehumification (I'm sure many other variable speed brands are also, I just don't know about installing other brands to say.) You could use the white rogers stat you mentioned. You could use (my preference) a honeywell IAQ. You could even use a standalone dehumistat mounted on the return duct, while using the cheapest stat on the market.

    The usage of the " " around standard was a good choice. It depends on your manufacturer, who you talk to, and your enviroment. Without getting to indepth, lets pretend 400 cfm is standard:
    2 ton system, goodman drops to 85% on dehumidification call. Thats 680 cfm, and you WILL get the correct cfm with goodman's variable speed.

    Knowing how much cfm your getting out of a psc blower is a crapshoot without knowing your static pressure.
    Lets say, with your static, high speed is 700 cfm, the next drop in blower speed on a psc blower puts you at 550cfm. Only 150 cfm, right? You just went from 400 cfm per ton, to 275 per ton.

    Mix that 275 cfm, and your wife has hot flashes, and likes the stat at 68. Your screwed.



    Correctly installing a variable speed system should not be hard for a moderately skilled contractor to do.
    Last edited by hvacvegas; 07-24-2011 at 10:15 PM.
    "Better tell the sandman to stay away, because we're gonna be workin on this one all night."

    "Dude, you need more than 2 wires to a condenser to run a 2 stage heatpump."

    "Just get it done son."

    Dad adjusted

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