Thermostatic Controls - Honeywell IAQ and dehumidification

Hello,
Very new to the world of HVAC and have just purchased a Honeywell IAQ. Can I use this thermostat along with my AC to dehumidify the house instead of buying a dehumidifier.

I currently have a Goodman Furnace Model GMV950704 and a Goodman AC model SSX140241 and a
GeneralAire Humidifier.

I'm afraid I don't understand what Dehumidify with AC means and how it works.
Currently I have nothing wired into the DHUM
Please help me understand.

Also I'm not sure where to connect the GeneralAire 1042 Humidifier..not sure if it requires the powered or non-powered setup

Thank

Can I use this thermostat along with my AC to dehumidify the house instead of buying a dehumidifier.
Depends on your home, and how much your A/C runs. If you have a very damp basment, and no vent, then you need the stand alone unit. But if your basement is dry, and have a vent or two open, then might be able to make do with out. But, if your system is oversized for your home, then humidity may not get low enough.

I currently have a Goodman Furnace Model GMV950704 and a Goodman AC model SSX140241 and a
GeneralAire Humidifier.


I'm afraid I don't understand what Dehumidify with AC means and how it works.
Currently I have nothing wired into the DHUM
Please help me understand.
When DHUM gets wired up, the blower on the furnace slows down, and with the air flow going slower over the A/C coil, it has a better chance of getting the humidity out. (Colder coil) Read on page 22 of the furnace manual if you have it.

Also I'm not sure where to connect the GeneralAire 1042 Humidifier..
Is it hooked up to anything now?

not sure if it requires the powered or non-powered setup
It's a non-powered unit..

Depends on your home, and how much your A/C runs. If you have a very damp basment, and no vent, then you need the stand alone unit. But if your basement is dry, and have a vent or two open, then might be able to make do with out. But, if your system is oversized for your home, then humidity may not get low enough.

Thanks for the answers Jay.
I'm new to home ownership and the joys of HVAC's so please forgive the noob questiosn...
Currently the humidity ranges in the basement from 60 to 70% and I don't have a vent. I will get a vent put in there soon, however the current humidity in the basement is 60 to 70%. Is this bad or acceptable for a basement?

I'm not sure if the AC is oversized or not, the hvac guys who put it said it was right size for 1900 sq feet back split



When DHUM gets wired up, the blower on the furnace slows down, and with the air flow going slower over the A/C coil, it has a better chance of getting the humidity out. (Colder coil) Read on page 22 of the furnace manual if you have it.

In my case with the Goodman 2-stage furnace the the AC, do I need to do any sort of special wiring on the Honeywell IAQ for the AC to do the dehumidification?

Currently I have set the honeywell IAQ for Dehumidification for AC and I see the dehumification screen but I don't think it does a whole heck of a lot since the humidity by the thermostat which is upstairs ranges from 55% to 60%.
I'm not sure if it's doing any dehumidification?


Is it hooked up to anything now?

It's a non-powered unit..

I re-visited this and the humidifier is actually 1042L and says powered on it. Currently its' wired into the HUM1 and HUM2.

Is there a way to test that this is actually working?

Currently the humidity ranges in the basement from 60 to 70% and I don't have a vent. I will get a vent put in there soon, however the current humidity in the basement is 60 to 70%. Is this bad or acceptable for a basement?
That is a bit high.. Mold grows around 50%, and ideal setting is around 45 to 50%.


I'm not sure if the AC is oversized or not, the hvac guys who put it said it was right size for 1900 sq feet back split
I don't seem too bad for a 2 ton unit in a your home, but then I don't know what you got for windows and attic insulation.



In my case with the Goodman 2-stage furnace the the AC, do I need to do any sort of special wiring on the Honeywell IAQ for the AC to do the dehumidification?
Yes, a wire off one of the R's on the EIM, to DHUM1, and another wire from DHUM on the furnace to DHUM2 on EIM.

Currently I have set the honeywell IAQ for Dehumidification for AC and I see the dehumification screen but I don't think it does a whole heck of a lot since the humidity by the thermostat which is upstairs ranges from 55% to 60%.
I'm not sure if it's doing any dehumidification?
Right now it's not doing much since the blower isn't slowing down much. It may try to over cool by 3˚ if the humidity is 5% above set point.. I set mine at 45%.


I re-visited this and the humidifier is acually 1042L and says powered on it. Currently its' wired into the HUM1 and HUM2.

Is there a way to test that this is actually working?
It's wired right.. It won't run till you run a heat cycle/mode on the furnace.

Yes, a wire off one of the R's on the EIM, to DHUM1, and another wire from DHUM on the furnace to DHUM2 on EIM.


I've connected the R from the EIM to the DHUM1 and the DHUM from the furnace fo the DHUM2 EIM.
Any way of testing this?

The HVAC installers cut the dehumidification jumper wire on the furnace and the yellow LED is now on? Is that correct for this setup?

As an aside the heat shows up as a Single Stage when the honeywell does a discovery...should I be forcing the thermostat to a 2 stage, but then I dunno what to put in for the CPH for stage1 and stage2.

I've connected the R from the EIM to the DHUM1 and the DHUM from the furnace fo the DHUM2 EIM. Any way of testing this?
Just look for the yellow LED.


The HVAC installers cut the dehumidification jumper wire on the furnace and the yellow LED is now on? Is that correct for this setup?
Correct.

As an aside the heat shows up as a Single Stage when the honeywell does a discovery...should I be forcing the thermostat to a 2 stage
Any settings on the IAQ that shows "E" should be changed to a number value. "Auto discovery" don't work with your furnace, so here are the settings I suggest for the IAQ. I skipped some since you could figure them out.. But, if you have questions on them, feel free to ask me.

110-0
172-1
174-1
176-2
180-1
220-2
240-2
250-3
280-0
340-0
342-1 (You have an outdoor sensor on this?)
370-1
372-3 (If you have outdoor sensor)
374-2
379-1
383-3
384-0


This is what I suggest for Dip switch setting on the board.
1-ON
2-OFF
3-OFF
4-OFF
5-ON
6-ON
7 and 8, You'll have to run the furnace to get the temp rise, and may need to be changed to get the right rise.

T-stat slection to 2-stage.

Just look for the yellow LED.



Correct.


Any settings on the IAQ that shows "E" should be changed to a number value. "Auto discovery" don't work with your furnace, so here are the settings I suggest for the IAQ. I skipped some since you could figure them out.. But, if you have questions on them, feel free to ask me.

110-0
172-1
174-1
176-2
180-1
220-2
240-2
250-3
280-0
340-0
342-1 (You have an outdoor sensor on this?)
370-1
372-3 (If you have outdoor sensor)
374-2
379-1
383-3
384-0


This is what I suggest for Dip switch setting on the board.
1-ON
2-OFF
3-OFF
4-OFF
5-ON
6-ON
7 and 8, You'll have to run the furnace to get the temp rise, and may need to be changed to get the right rise.

T-stat slection to 2-stage.

Thanks a lot for the information...for a little while there the humidity dropped to 51% yesterday but jumped up again to 60% this morning...I've since made the recommended changes....but not sure how to determine what to pick for 7 and 8. I guess will have to wait for the winter when I turn on the heat

Thanks a lot for the information...for a little while there the humidity dropped to 51% yesterday but jumped up again to 60% this morning...I've since made the recommended changes....
What is your temps outdoors and humidity? What is your temp settings, and do you leave the temp setting the same all the time or have temp change up and down? Also, humidity setting on Dehumidify mode?


but not sure how to determine what to pick for 7 and 8. I guess will have to wait for the winter when I turn on the heat
Do this fall when you start using the furnace, you can do it now if you want.

What you need to do is a temp probe of some type and take a temp reading at the filter next to the furnace.. Furnace should be running 10+ minute. Then take a temp reading on the supply above the A-coil. Take supply temp reading and take away the return temp reading, that should give you the temp rise.

Look at the model # sticker on the furnace, and you should see the temp rise range.. The rise should be in mid range of what the nameplate is saying.

What is your temps outdoors and humidity? What is your temp settings, and do you leave the temp setting the same all the time or have temp change up and down? Also, humidity setting on Dehumidify mode?


For example today the outside is 20 C and humidity is 78%. The temp inside is set to 24 C and they are left the same all the time. the dehumidify is set to 45%.

However the humidity in the house is showing 62%

For example today the outside is 20 C and humidity is 78%. The temp inside is set to 24 C and they are left the same all the time. the dehumidify is set to 45%.

However the humidity in the house is showing 62%

If the temps outdoors is cooler, the A/C is not going to run much, only time it's going to run is "over cool" mode, I'm guessing the house temp is 3˚ below set point?

If the temps outdoors is cooler, the A/C is not going to run much, only time it's going to run is "over cool" mode, I'm guessing the house temp is 3˚ below set point?

Yah...it's been a pretty cool summer up here..so if I understand correctly the if the Humidity is at 62 and the set temprature is 24C then it should cool to atleast 21C to try and get the humidity down?

I dont' see this happening...I see it stop at 22C

Yah...it's been a pretty cool summer up here..so if I understand correctly the if the Humidity is at 62 and the set temprature is 24C then it should cool to atleast 21C to try and get the humidity down?

I dont' see this happening...I see it stop at 22C

Ok, I looked at the manual, You are using C˚ temp reading, so it will only over cool 1.5˚. If it' was F˚ reading, then it will over cool down to 3˚.

Ok, I looked at the manual, You are using C˚ temp reading, so it will only over cool 1.5˚. If it' was F˚ reading, then it will over cool down to 3˚.

Right..I didn't catch that :-).... I guess my only other option is to get a dehumidifier for the basement

Yeah, that will be the best thing to do help get the humidity down.

Yeah, that will be the best thing to do help get the humidity down.

Thanks a lot Jay for all your help..much appreciated