Lets talk cooling, the whole room

As we see here in Wendell’s latest video, he has not one but two wall mounted AC units in this room.

I have a computer room that has one ducted vent and one door, thats it. I need something like this to help cool the room down when multiple computers are running and heat builds up.

Does anyone have experience with units like this? Are they hard to install yourself? Are there brands to avoid? Brands you recommend?

EDIT: scratch the DIY - in my state you must be licensed to install these split units shown above.

Thanks in advance!

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Yes and no. In principle, it can be done by an accomplished and competent DIY person. But no, it’s illegal to install yourself as it involves seriously hazardous materials. Unless you are a certified refrigerant mechanic or engineer, any work you do on these units is an environmental violation, which carries prison time.


Of course you can simply and easily dismiss my warnings and put in a unit all by yourself, but unless you can prove a certified refrigerant company installed the unit, and the install can be traced at said company, insurance isn’t gonna pay out in case anything happens. And it doesn’t have to be related to the split-unit you’ve installed. Never mind if the insurers come by for something unrelated, expect a gi-normous increase in your premium, if you’re lucky enough they don’t cancel your insurance outright on the spot :roll_eyes:

As for brands, the A/C installer company has a few options. I should know, I’m a refrigerant mechanic/engineer (but not working in that field) :stuck_out_tongue:


I didn’t think about that. Thanks for the warning. Consider it heeded.


My plan next month is to add two 3" duct vents in the wall behind my PC desk and have them go up the wall into the attic and merge into either a 6" or 8" duct fan that then exits right near an attic vent. I will be using a molex 4 pin (only with 12v and ground in it) connector to 2 bare wires that I connect to a 12v relay coil. The contact side of that relay will connect to the power cord up to the fan. That way when the PC turns on it automatically turns on the exaust duct fan. That will suck the hot air from my PC out of my bedroom and send it right outside the house which will keep the bedroom much cooler. This new OCed threadripper and my OCed 3090 put out a ton of heat right now. I can do the project easily myself. and looking at it all should only cost around $260 in supplies.

and for anyone wondering why two 3" ducts, that is because those will fit inside the wall. 4" is hard to fit, and anything larger is impossible. So Im using two 3" ones and converge into a larger one right before the fan to get enough airflow and fit inside the wall.

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Another thing to consider is the INVERTOR type of AC units for a more efficient type of cooling, pioneered by Toshiba in Japan back in the day.

Not so common here in NA but gaining momentum.


How about MRCOOL, mrcool? They market mini-splits that are expicitly DIY.

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From their website:

NOTICE: MRCOOL® products must be installed in accordance with all applicable local, state and federal codes and regulations. Unless explicitly stated otherwise, installation must be completed by a licensed / certified HVAC technician. ALL electrical connections to a power source must be performed by a licensed electrician and comply with local, state and federal electrical codes and regulations.

Basically, wot I said :wink:


Live in a cold spot of Canada, that will solve the cooling issue

Honestly hope you all take this as a joke


There are specialised Split-AC-systems that just circulate water between the “condenser” and the “evaporator” Example for such a System, which could be DIY installed.

To repeat what @Dutch_Master said, most refrigeration involves:

  • grid voltage electricity (:zap: :fire: )
  • Hydrocarbons under pressure (:fire: :boom: ) (Example: R290 = Propane, R410a = Ethane-compound)
  • insurance issues (:money_with_wings: )

Look into their behaviour in regards to IoT and Right to Repair, if the system dies the moment the server goes down, I’d take big steps the other way.


I believe LTT did a DIY on AC:

Like someone above mentioned, you will at some point need to have a professional inspect your setup. My thinking is, have a pro come over and take a look at your entire setup, discuss what you can and cannot do, if there is anything you can do yourself to help speed things up like routing cables or ducts et cetera.

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They didn’t. They had “Brian the Electrician” who also happens to be an HVAC mechanic. Sure, Linus helped installing the stuff, but this Brian chap was/is responsible for the entire setup.


To drive @Dutch_Master’s point home, look what kind of funtime you can also experience when servicing AC:



Flammable gasses are fun. :neutral_face:


Wrong address. You need to look at https://mrcooldiy.com/

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The entire state of Kansas does not require HVAC certification to do ANY HVAC work. Seriously. Also the only time i need to be a certified electrician is if i am connecting to the City owned drop in the right-of-way.

And due south is Oklahoma, where you need to be a certified electrician to flip a breaker.

So if you want to do it yourself, check local regs.


This is why I find the US so weird, and to be quite frank, a bit insane. State to state laws is wild and there is still the federal laws above them and city laws beneath it all.


I live in an old RV and it does not have very good insulation. I took one of the Portable air conditioners that would normally be in a room when you’d run the exhaust out the window and I set it up outside of my RV and ran the cold air in and left the exhaust to stay outside. It works good to cool off my little bedroom when It’s 40 degrees Celsius outside. Perhaps you could set up something similar to help cool off your room.


While this is true, your insurance may have different requirements. If you do any DIY electrical panel work, for example, and there is a fire, the insurance company can point at the panel and say “you didn’t get a pro for this, that’s why the house burned, you’re on the hook for your own mess”


This is very similar to EU countries, and you should really think of it this way.

There are EU regulations, Country regulations and City regulations.

The US is really 50 countries with a common economic system, free movement agreement and mutual defense (and offense, lookin at you, grummy bear) agreement.


Most stuff we can lay out the stuff, pull sites, route cables/ conduit, and just get a sparky to check the terminators/connections and sign off ar the end. So like a couple hours labour, instead of days. Can you do something like that?

Presumably not for pressurized gas in AC tho…