Thermostat recommendations for Amana AMV9

[tas]

Just looking for thermostat recommendations for an Amana AMV9 furnace (70,000 btu). We're working out final details with the contractor this week, and I'd like to get this part right. We haven't discussed details yet - he did mention a digital talking thermostat, but I have no idea which one that might be.

I'm assuming that with this furnace we would want a two-stage thermostat. Any specific brands/models that would be especially appropriate? Previous contractors (estimates) have bluntly told me that there's no reason to use a two-stage thermostat with a two-stage furnace, that my single-stage thermo will do just fine. I've always questioned that thinking, especially after what I've read here in the past. If we're spending the bucks on a two-stage furnace, I'd sure like to get the most benefit from it.

Also, should we consider adding a humidistat for better dehumidification during summer (A/C will be Amana RCE, 2-1/2 ton). If so, I am clueless on what to tell the contractor about that - in the past I've gotten blank stares when asking about it, so I'm guessing it isn't widely done around here. We're in MN, but we have our share of humid 75 degree days when it would be nice to be able to pull some humidity out of the air without cooling the house to 65 degrees...

[beenthere]

Vision pro 8321, it can do up to 3 stages heat, 2 stages cool, has cool to dehumidify, and fan cycle built into it, and yes get the humidistat for the lower temp days.

[BaldLoonie]

The Vision Pro is a great stat. I don't like the overcool to dehumidify though. If you want dehumidification, either slap a simple humidistat in the return and hook it up that way or use a White-Rodgers 1F95-391 which has the same capability built in. Both methods slow the blower if humidiy is high. Of course there has to be a call for cool for it to work. Tradeoff either way.

[beenthere]

Thats why I said to get the humidistat also, it will minimize over cooling to dehumidify.

Only have 1 set up this way so far, and since the season is just beginning, I can't tell you how well it is working yet.

[tpa-fl]

I have both a VisionPro 8321 & WR 1F95-391.. and actually prefer the VisionPro. The VisionPro's only controlling a single-stage AC system, but controls the blower speed (low/high as stage 1/2). Even with this arrangement, I'm getting superior dehumidifcation without major overcooling. The WR is controlling a 2 stage / variable speed system and gets the job done, but it should. I do find that it doesn't always get the humidity under the setpoint with it set to not overcool. If I allow it to overcool, it always gets it, usually without dropping more than a degree or two. On both stats, I never found overcooling to be objectionable or even noticable.

I think the WR handles remote sensors far better, but is limited to 3 sensors, whereas the VisionPro can have 9+. The WR doesn't handle power outages smoothly, losing its time setting, which is an issue down here in FL, probably less of an issue elsewhere. The VisionPro has a 10-year lithium battery inside to keep the clock going, and the VP also properly handles daylight savings time. The VP also has a much better recovery algorithm than the WR, *BUT* won't use recovery when controlling humidity. The VP seems to have better temperature control and staging control than the WR.

[tas]

OK, you guys are gonna lose me pretty quickly here! Let's see if I understand this:

1) Both thermostats can control a two stage furnace, and can slow the blower for dehumidification when needed, if proper setup (humidistat) is in place.

2) Both stats can overcool to dehumidify, which sounds to me like a setting where you tell the thermostat to go ahead and cool below the setpoint if humidity is too high. Blower still runs at normal A/C speed. Am I close?

3) Adding a humidistat allows the blower to be slowed when humidity is high, thus causing the A/C to run longer to cool to the set point, which gives longer run time for better humidity removal.

4) Do both stats require a separate humidistat in the return? Or is that the capability that the W-R has "built in"? I wasn't sure if the "built in" reference meant that the W-R was able to work with a humidistat directly without special wiring like the VisionPro seems to need, or if I'm all confused here.

5) How much is the blower slowed when using a humidistat? Is it a fixed or variable amount, given that this furnace has a variable speed blower?

6) Can both of these stats also control a humidifier during heating season?

Sorry for so many questions, but as I said in my original post I normally just get blank stares when I ask about dehumidification and humidistats, so I feel like I need have at least a basic understanding of what's needed and how it works so I can discuss my needs intelligently. It's hard to push for something when a contractor tells you you don't need it, which I've heard repeatedly on two-stage stats and dehumidification. They tell me there's no reason to spend the extra $$$ - too little benefit, not needed, etc. I still wish one of you guys worked in MN!

Maybe that's a valid question - is the extra cost for dehumidification worthwhile in MN? I know the two-stage stat would be, as it would be plenty busy during the heating season. I guess it doesn't seem to me that adding a humidistat should add much cost, and the potential benefit on humid days could be pretty high...

[classical]

Amana has the thermostat you want can't remember model number I will look it up. It is two stage ht/cool has dihum mode and is made for Amana by White Rodgers. I have dealt with all of the available high-end t'stats and this is best around.
Nice feature set the fan to continuous set humidity level and if is rises above set level it turns off the fan. This is the model I use with my RSG units and AMV furnaces.

[tpa-fl]

Okay, bunch of questions, here come the asnwers:

1) Both stats have humidistats in them and will slow down the blower for additional dehumidification.

2) When cooling to dehumidify, the stats will hold the AC in the low stage, to promote a longer run-time with less cooling (idea being that it'll pull more humidity out)

3) Correct

4) Both stats have humidity sensors internally-mounted and do not support remote humidity sensors, but both support remote temp sensors.

5) This is dependent upon the furnace and how your HVAC installer has set it up. On most (if not all?) variable-speed systems, the speeds can be adjusted.

6) Only the White-Rodgers stat supports a humidifier. If you're thinking of adding one (even if in the future), get the WR stat & have them pull the extra wire for it.

Just off the top of my head, the difference between the regular 2-stage VP & humidity-sensing 2-stage VP is about the cost of a decent dinner. (Forum rules prevent me from being specific) So, skip dining out once or twice and you'll be there. Keep in mind that you can always disable features on these stats if you don't want to use them, but you can't ever add features to a stat which lacks them. I'm still sold on 2-stage stats, can't understand why anyone would want to slap a single stage on a multi-stage system, unless they didn't want to pull new thermostat wire (lazy).

[dgk]

TAS,

I am the factory rep for Goodman/Amana so let's put this one to sleep once and for all.

1) The AMV9 works best with a two-stage heat thermostat, period. If a single stage heat thermostat is used the furnace will run on low stage for a "fixed period" of time, either 5 or 10 minutes. You can only get "true" thermostat-driven two-stage operation with a TWO-STAGE Heating Thermostat. This will allow you to run on low stage longer without forcing the furnace to go into high stage heat, thus not allowing you to operate at the lowest utility cost possible.

2) While the AMV9 already removes more moisture than standard furnaces because it has a variable speed motor, which operates at a lower fan speed (50% power for 30 seconds, then will ramp up to 82% speed and stay there for around 7.5 minutes, dehumidifying the air in the home. You are already getting very good humidity removal.

3) You CANNOT use a humidistat with our furnace as someone previously stated. Our Installation Instructions plainly state if you want additionally humidity removal: "For proper operation, a "DEHUMISTAT" applied to this furnace must operate on 24 VAC and utilize a switch which "Opens on Humidity rise." Our part # DEHUM1 should be used. The use of this dehumidistat is NOT a requirement, just an option.

Hope this clears up the matter.

Amana Product Specialist

[chris31849]

how does everyone feel about the aprilaire 1700 as an alternate to dehumidify mode ?

[beenthere]

Originally posted by dgk
TAS,





3) You CANNOT use a humidistat with our furnace as someone previously stated. Our Installation Instructions plainly state if you want additionally humidity removal: "For proper operation, a "DEHUMISTAT" applied to this furnace must operate on 24 VAC and utilize a switch which "Opens on Humidity rise." Our part # DEHUM1 should be used. The use of this dehumidistat is NOT a requirement, just an option.

Hope this clears up the matter.

Amana Product Specialist

Thanks, I didn't know that.

[mayguy]

I think we can get by with out the humidstat for our Summer months in MN, Just as long you are not the person who opens the windows at night, close them in the afternoon when the temp is up, and run it for 5 hours.

From what Tas has said how the Amana system works, you won't need it.

I love the VisionPro, and have it in my home.. Easy to use, and if you run 7 wires, you can light the back ground all time. :-)

[muswell_hillbilly]

tas -

We just installed this exact Amana unit, right down to the BTUh rating! And with it, we installed the VisionPro 8321. System's been running for a week now, and we couldn't be more pleased. Good Luck!