automating humidity and temperature with a/c

[Overgrowtho]

I have a Smart Humidity and Temperature Sensor/Display (Tuya brand) and Aircon which can be controlled by a Smart Universal Remote (Tuya) triggered by fluctuations in the sensor.

Basically I can use the sensor to trigger different states or power on/off the aircon.

I understand that I want to use this to keep the temperature and humidity in a certain range.

I can do that for either/or/both humidity or temperature easily with the app.

However, where I am getting confused, is concerning: how I can do that for both at the same time? Using my setup?

Lets say I want humidity at 48-52% so I automate that into the system. And I want temp at 74-76 for example, so I automate that too. But I cannot use the Aircon to ADD MORE humidity if I need to. I also cannot add heat with my system if I wanted to. Nor can I reduce temperature while keeping humidity steady.

Bascially it seems like I should have an additional machine which can add or reduce humidity as needed? And one that can add heat if needed? This way, I have total control and the machines wont get confused? Are there recommended humidifiers that also dehumidify? I have a very small space of 4x4x4.5

 

[Spazz24]

For such a small space you’re making it more complicated than it needs to be. I’m running a 4x8x7 space and all I do is run an ac during lights on set to a certain temp in the room my tent is in and also a dehuey during lights on outside the tent in the room. If you need to add humidity just shut off the dehuey and turn on the humidifier.

 

[NukaKola]

A dehumidifier and humidifier are different pieces of equipment. However, air conditioners dehumidify as a by-product of cooling the air. Some air conditioners also have dehumidify settings that you could use during lights off but you would most likely have to switch you AC from "cool" to "dehumidify" every time it's lights on or lights off.

During lights on the air conditioner and lights will act as a dehumidifier. If you live in a region with low humidity you may need to supplement with a humidifier if your RH is too low. I would recommend an evaporative humidifier over a "mist" type. If you live in a humid region and your RH is still too high during lights on with AC running then you may need to have a dehumidifier running as well.

During lights off, you will most likely need a dehumidifier to keep the RH down and if you are in a cold climate then possibly a heater.

I'm not exactly sure how your smart controller works and if it is able to be programmed for multiple devices on specified outlets. If you are not able to control multiple devices and assign specific outlets for those devices than you can easily add a humidistat for a dehumidifier/humidifier and thermostat for a heater if you end up needing one.

As mentioned above you are working with quite a small space so it doesn't really make sense to use a ton of different pieces of equipment that most likely won't fit in the space.

https://www.amazon.com/Humidity-Controller-Inkbird-Humidistat-Pre-wired/dp/B01J1E5LWM/ref=sr_1_5?dchild=1&keywords=humidistat&qid=1598217515&sr=8-5

 

[Overgrowtho]

Okay true, its a small space with limited equipment I could place in there (even having the aircon, c02 and 3 x 245 watt LED lights is a lot. I think it will be best to wait and see what, if any humidity issues arise and then go from there. I live in a humid and hot tropical area, so I think that fortunately the humidifier and heater will not be necessary. Meaning, I could be totally fine with the aircon to simply cool down and dehumidify as needed. If I want to add humidity or heat I suppose I can always look at that again later as needed.

 

[sf_frankie]

I set my minisplit to 87F and my dehuey to 55% and it pretty much stays stable 24/7. Temps drop into the low 80s during lights off so the minisplit isn’t even on. I have a fancy environment and co2 controller but got rid of it cause the built in sensors on my AC and dehuey did just fine. It was 110F outside all week last week and I didn’t have any issues.

 

[Overgrowtho]

Hi Frankie, interesting that you ended up with a more simple solution even after having bought the fancy environment and Co2 controller!

I am curious, how do you control the C02 in this case then, without the controller/sensor to manage the PPM? Do you just have it all caluclated out and on a timer?

 

[Overgrowtho]

I'm in a super humid and hot zone. Today I tested out the air conditioner. It's not an inverter.
Using a sensor, I tried to set it to dehumidify when the humidity was above 60 and to cool when temps went above 75. Well, it was kind of a disaster because the humidity was fluctuating from 40 to 90% really wild. Therefore I decided that I likely definitely need a separate dehumidifier.

Seeing as my space is so small and I have a drain to use, I ordered the following one (20$ from China):
View attachment 4665465

 

[Overgrowtho]

Anyone else have a terrible time with trying to make an airconditioer control humidity and temps at the same time?

seems it will be much smoother with two devices!

 

[Overgrowtho]

I had it all wrong. I needed to use the drying setting in the aircon to get the humidity and temps right. At the same time, limit to my himidity range using smart home techs.

 

[nunyabidness420]

I'm in a super humid and hot zone. Today I tested out the air conditioner. It's not an inverter.
Using a sensor, I tried to set it to dehumidify when the humidity was above 60 and to cool when temps went above 75. Well, it was kind of a disaster because the humidity was fluctuating from 40 to 90% really wild. Therefore I decided that I likely definitely need a separate dehumidifier.

Seeing as my space is so small and I have a drain to use, I ordered the following one (20$ from China):
View attachment 4665465

Those peltier module dehumidifiers don't really do anything.
I'm also in a hot and humid environment (for about 9 months out of the year) and grow in a small space.
The separate AC and dehumidifier combo is what I'm using until I can get a purpose built unit made.

 

[Overgrowtho]

Thanks for your reply, a few questions:

I did not know what a peltier is or that this model is one. I have a tiny space so it might help a bit?

What kind of purpose built unit is optimal?

And may I ask why do you use a separate dehumidifier if the AC can also dehumidify efficiently?

 

[nunyabidness420]

It might help but I've had something similar and they only pull a couple ml of water out of the air per hour. Compare that amount to the amount of water you're adding to the plants per day and it hardly makes a dent.

I'm using a separate dehumidifier mainly to dehumidify when the lights are off and the ac isn't needed to cool the air. A dehumidifier also heats the air which is sometimes needed to prevents temps from dropping too low on the few months out of the year where heat is not a concern and/or when the lights are off.

Both of these appliances are composed of a compressor, condenser coil, expansion valve, and evaporator coil and are arranged for efficiency for either dehumidification or cooling, not both, and are inefficient when temps/humidity are close the values set into the controller.

A dehumidifier works by sucking in air and cooling it so the moisture condenses out of the air. It then takes that air it just cooled and heats it back up so it absorbs more moisture when its expelled back into the space the air came from. The air is heated with condenser coil, which means its utilizing "waste" heat to heat that air. But the air coming out of the unit is hotter than the air going in so the AC gets turned on to remove that heat.

An AC dehumidifies as it cools, but if the lights are off and the temps aren't high enough to have the AC kick in, there is no dehumidification. If you set the AC to dehumidify mode when the temps are low, they will use a separate heater to bring the temps back up which means its using more power since it doesn't utilize the "waste" heat like the dehumidifier does.

The unit I want to build would basically combine the two so it can use "waste" condenser heat if needed for optimal efficiency.
Size is also an issue for me as a typical AC is too big for the space/lighting that I'm using.