Every week the Hackaday tip line is bombarded with offers from manufacturers who want to send us their latest and greatest device for review. The vast majority of these are ignored, simply because they don’t make sense for the kind of content we run here. For example, there is a company out there that seems intent on sending us a folding electronic guitar for some reason.
For starters, that’s what happened when CoolingStyle recently contacted us about their Cooler Max. The email claimed it was the “World’s first AC cooling system for gaming desktop”, featuring a “powerful compressor capable of providing good cooling performance”, and was able to automatically bring the computer’s temperature down to as low as 10℃ (50° ) F). The only promotional image in the email showed a fairly chunky box connected to a gaming rig with a pair of flexible hoses, but no technical information was provided. We sent the email around the (virtual) water cooler a bit, and the consensus was that the fancy box probably contained little more than a couple of Peltier cooling modules and some RGB LEDs.
The story almost ended there, but there was something about the email that I couldn’t shake. If it was just using Peltier modules, why was the box so big? What about the “powerful compressor” they mentioned? Could they be playing some cute puns, and were actually talking about a centrifugal fan? May be…
It bothered me enough that after a few days I came back to CoolingStyle and said we would accept a unit to look at. I thought whatever ended up in the box would make for an interesting story. Plus it would give me an excuse to put together a new entry for my Teardowns column, a once-regular feature that has sadly been neglected since I assumed the title of managing editor.
There was just one problem…I’m not a PC gamer. Once in a while I start up Kerbal Space Program, but even then my rockets are rendered on integrated video. I don’t even know anyone with a gaming PC powerful enough to strap an air conditioner to the side of the thing. But I have a lot of experience pulling weird things apart to figure out how it works, so let’s get started.
While I was waiting for Cooler Max to make it over the ocean, I decided to look into the company myself. Browsing their website, you’ll find an impressive selection of small water coolers used for things like cooling industrial lasers or high-performance servers. As explained on the website, the key to CoolingStyle’s product line is their palm-sized compressor, which allows them to squeeze an entire cooling system into a box that can fit into a standard server rack.
Pulling the manual for one of their coolers, we can see that the control panel used is identical to the one shown in the Cooler Max promotional images. At this point I was actually getting pretty excited – this thing was looking more and more like the real deal.
In fact, one of the coolers offered at CoolingStyle, the Q Series Micro Water Chiller, appeared to be very similar to the overall design of the Cooler Max. Could it be that this company took one of their high end industrial cooling units, retooled it for the gaming crowd with some RGB LEDs?
An impressive machine
I have to admit, as soon as I got the Cooler Max out of the box, I was impressed. The case is as big as a medium-sized desktop PC, and is built like a tank. There are some fit and finish issues here and there with the case, but nothing that can’t be forgiven considering it’s a pre-release prototype.
In terms of construction, it’s actually very similar to a desktop PC case, with sheet metal side panels that slide off when you remove the rear thumbscrews. The front and back panels are also metal, while the top and bottom appear to be injection molded plastic. In fact, I wouldn’t be surprised if it’s some kind of jellybean PC case that’s been customized, since there’s even a support panel on one side that looks like it could have been meant to hold a motherboard.
Towards the front of the Cooler Max is a Mean Well LRS-350 power supply that provides 24V to the compressor and most of the electronics, and around the other side we can see a regular adjustable regulator board that is set to 5V and is connected to the dual The 120mm RGB fans on top of the device. Since the main control board for the compressor already has a functional 5 V rail, the addition of the separate regulator seems a bit of a bodge; as if the regulator on board was not up to the task of handling the large luminous fans. Anyway, I’d be surprised if this wasn’t changed for the production units – even just dropping down to a fixed 5V regulator would be cheaper.
The compressor control board has quite a lot going on, and judging by all the unused connectors, it has considerable untapped potential. There is clearly a serial port right at the top of the board, which may be the subject of future experimentation. Overall, the build looks pretty nice here, and I appreciate the little touches like the insulated spade connectors. The relays could be a point of potential failure along the line, and even if they are not connected, it would not be very difficult to replace them.
On the inside of the front panel we have an additional PCB. This is the one that seems to feature in most of CoolingStyle’s products, so as you might expect, it again has a number of unused connections for this relatively simple application.
While the two main ICs have unfortunately had their labels removed, the pair are obviously a microcontroller and a dedicated LCD controller. Note the clearly labeled SWDIO/SWCLK pins on the bottom header: that’s a Single Wire Debug (SWD) interface, and a decent hint that our mystery MCU is actually an STM32. Like the previously mentioned serial port, this interface is ripe for future experimentation. Matthew [wrongbaud] Everything has put together some good recipes on what kind of information can be gleaned from SWD, for those unfamiliar with ARM’s answer to JTAG.
The conformal coating on the board is a nice touch given the potential for moisture, and the screw terminal connection for the thermocouple was a welcome surprise. Small details, but they speak to the overall build quality.
Water cooling system
I won’t spend much time on this side, as far as I can tell this part of Cooler Max looks completely off the shelf. While I obviously don’t have one to compare it to, I’d be surprised if this is the kind of thing you’d find in any of their professional coolers; and is likely one of the cost-cutting measures they’ve used to create this more consumer-focused device.
There are no identifying marks on the water cooling components, but very similar units can be quickly found online. Some custom modifications may have been made, such as adding the port for the thermocouple, but certainly the pump, fittings, and reservoir are all standard components that you’ll find inside any water-cooled gaming PC. Not that there’s necessarily anything wrong with that.
So at this point it should be clear that the Cooler Max is indeed a small (relatively speaking) cooling unit. Just like an air conditioner, it has a compressor and a substantial condenser along with large fans to keep it cool. But the difference is that instead of blowing cold air, this device is designed to pump cold water.
So instead of an evaporator coil with another set of fans blowing over it, the Cooler Max uses a heat exchanger to cool the water pumped through the internal reservoir. Unfortunately, the nature of the soldered copper connections on these types of cooling units makes it impossible to completely take them apart without releasing the coolant, so we can’t get a very good look at any of these components in isolation.
But with the water reservoir removed, and the power supply moved to the side, we can get a pretty good view of all the core components. The silver radiator in the back is the condenser, the black cylinder mounted in the bottom of the case is CoolingStyle’s miniature compressor, and the foam-wrapped box in the middle of the picture is the heat exchanger. The thicker insulated pipes are for water, and if you look at the top of the picture near where the AC power enters the unit, you can see the bulge on the flow sensor that it used to determine how much water is actually being pumped through the system.
Before I wrap things up, I think it’s worth noting that the Cooler Max is perhaps one of the most usable devices we’ve seen during this teardown series. Replacements for so many of the components, from all the water cooling equipment to the fans and power supply, can be picked up at your chosen online store without jumping through any hoops.
The design and construction of the device is such that, as you have seen here, it can be taken almost completely apart without anything more exotic than a screwdriver. All the electrical connections are sockets or screwed down and there wasn’t a blob of glue anywhere to be seen inside the thing.
Amazingly, they even included a service port to add coolant, something you’d normally have to hack in yourself. The compressor uses R134a, which at least here in the US you can easily pick up at the auto parts store.
Of course, as a prototype, some of these features may be due to its one-off nature. The latest devices may remove the service port and replace half of the internals with proprietary bits and bobs. May be. But we can dream.
OK, but does it work?
As I said at the start, I’m not a PC gamer. This is also not a site about PC gaming. So I’m not qualified to judge Cooler Max in that context. That’s likely to upset some people, perhaps not least the fine folks at CoolingStyle.
For the record though, I hooked it up to a basic water block to do some simple testing – it definitely gets cold in no time, and when I dunked the block into a bucket of hot water, the Cooler Max went crazy and brought it down to below room temperature in a minute or two.
I can also tell you that the Cooler Max appears to be very well made, and designed so that you can open it up to fix it, and potentially modify it, without the risk of breaking it in the process. It’s a feature we don’t see often enough, so respect to CoolingStyle where it’s due.
Considering there’s nothing else like it on the market, it’s hard to judge the initial Kickstarter price of $699. It is a lot of money. But the closest you can really compare it to on a technical level would be a small travel air conditioner, and shopping around, they cost about the same. Of course, at the end of the day, if you have a gaming PC powerful enough for you to even consider something this elaborate for your cooling needs, that number probably won’t break your budget.