This Desktop Air Conditioner Is Really Cool!

[Mike] works in a 50+ year old building with unreliable air conditioning. It often reaches 80°F inside during the summer, and he once measured it at 98°F. Rather than burn sick days, he became the envy of the office when he built this awesome desktop air conditioner.

The problem with knocking holes in the office walls and installing window units is that they must vent heat somewhere. [Mike] has overcome adversity and harnessed the power of the heatsink, only in reverse. His desktop a/c unit is made from two 28oz cans plus a 20oz can for the ice bucket. [Mike] used a side-vented CPU fan, which is vital to his design. He secured the heatsink to the base of one 28oz can with a self-tapping screw. This can is the upper chamber. [Mike] made a base from the other 28oz can, drilling holes for the CPU fan wires, the power cord, and a sweet light-up rocker switch. He used Gorilla Glue to affix the CPU fan to the base can.

Hot, stale office air is drawn through the ice in the 20oz can, which is nestled in aluminum foil to maximize heat transfer to the heatsink. The heat in the air gets absorbed by the heatsink, and the CPU fan kicks out cool air in 20-30 seconds.

Hacked AC and ash filter

Moscow is in a bit of a hot spot right now, dealing with a heat wave and enormous wildfires. The combination of smoke, ash, and heat was driving Andrew up a wall so he built a contraption to provide some relief. It has two chambers, the bottom houses ice water, the top is an air baffle. A small DC fan pumps air into the upper chamber where it encounters the water being sprayed in from the lower reservoir. What results is a heat exchange similar to other diy AC setups we’ve seen. But Andrew also notes that after running the device for a while the smell of smoke and ash is gone. Can this setup be seen as an effective way to trap airborne smoke particles?

Network enabled window air conditioner

It’s no secret that the central US is feels like a very humid oven right now. [Erik's] window AC hack might help you out if you’re coping with triple-digit temperatures. He added network connectivity to the unit above but the picture is a bit deceiving. The blue CAT-5 cable that enters the bottom isn’t connecting directly to the network, but extends the up and down button connections for the unit to an external relay board. From there he uses an SNMP board to connect it to the network and uses PHP commands to reset the temperature. The unit has a working range of 66-88 degrees Fahrenheit so he cycles enough button press to reach the maximum or minimum level, then sets the desired temperature (avoiding the need to know what temperature the unit is currently set at).

If you’ve got an AC unit with a remote control you could always use an IR device to patch into the system for similar functionality.

Recharging AC with propane

As the summer heats up an air conditioning system is a necessity in many climates. [Grayson's] system suffered some damage over the winter that caused it to vent its refrigerant, avoiding an explosive situation. Before he can chill out inside he’ll need to recharge it and he’s chosen to use propane in his cooling system. According to our friend Google this is not his original idea, but has been done many times before. [Grayson] makes the point that although propane is flammable it’s not necessarily any more dangerous in a fire than Chlorodiflouromethane, or R22, which is the nasty little gas that fled his system for its new home in the upper atmosphere.

The video above includes a brief explanation of recharging the system and the tools needed. We’d need to mill this over for quite a while before working up the gumption to give it a try. For now we’ll stick to [Grayson's] more pedestrian hacks like making some servo motors sing or easing our yard work woes.