First off, thanks for all the replies!
The NodeMCU cannot power fans, it can control a driver that powers the fans. The type of driver depends on the type of motors in the fans.
You will need a power supply capable of supplying the voltage and current required by the fans.
Do I understand correctly that you want to be able to reverse the fans?
Can you post data sheets for the fans?
I figured as much, I thought there might be a need for a relay board that would have its power from a buck convertor. Let me update the diagram.
I was hoping that I could reverse the fans if possible. The point of this fan project is to regularly vent humid air from a closed environment (terrarium) based on a timed schedule. The enclosure will change humidity levels throughout the day due to misting, and to keep the glass clear I was looking to pull air out of the enclosure (there are passive vents that will allow in coming air) and on occasions I'd also like to push in air. The fans being used are going to be smaller PC style fans, but from what I read from another post this might not be doable. I thought the fans could be set on either a push/pull depending on the flow of current, but from what I'm reading that is not the case. It's been a while since I've tinkered with PC fans. In most cases I remember the orientation of the fan determined the flow in the case of a PC, but I thought that may have been limited to the connector as they only connect one way. The fans I'm going with are small and not high CFM, but I'm banking on them assisting with pulling out higher heat/humidity with convection.
As I'm going with some off brand Chinese fans, I only have a little information in regards to specs:
Dimensions: 40mm x 40mm x 10mm
Voltage: 12V DC
Working Current: 0.08A
As groundFungus intimated, your description is such a high level that there's not much guidance that we can provide without a little more detail.
You said something like, "I want to get from point A to point B using wheels".
So, here's a start. Everything in my home is controlled using MQTT over WiFi. You can start your research here.
Sorry for the 30,000ft view on this. I was trying to look at the big picture to see if what I'm after is or is not capable with what I had in mind. In the analogy of "wheels" you posted, I'd like to clarify that I was trying to ask if the hardware (specifically the NodeMCU) would be able to accomplish this task as said wheel, or if what I had in mind was trying to use a rectangular wheel which would be a non starter.
I'm familiar, briefly, with MQTT as I used it in the past with another project when it came to NodeMCU's collecting data and kicking the file over to a remote database for trending. I'll have to look into it further for the control aspects of devices. Thanks!
If you mean change direction of airflow, then NO.
No PC fan can do that. You must physically flip the fan.
I swore I remember that some PC fans were bi-directional. Again, this could be completely wrong, but I thought I tinkered with a set years ago that were able to be toggled as input or exhaust. I just tested on a 5V fan I had laying around and well, it looks like the standard may be single direction flow.
Here is the updated diagram per the inputs of what was mentioned. Does this help make things a little more clear?