the technology is still evolving and may take several more years to catch up.
the technology is still evolving and may take several more years to catch up.
This situation is quite ironic because they seem to be lagging behind in size compared to their actual existence... but let me clarify.
I retrieved a heater core from my 1999 Isuzu NPR-HD, which had been leaking after almost 300,000 miles.
According to the FSM, it releases 4.5 kW of heat—equivalent to 4,500 watts. This comes from a 45mm thick, 170mm wide, and 220mm tall unit.
Even at an operating temperature of 100°C (with a 25°C difference from ambient), it’s significantly hotter than the temperatures we need for our CPUs.
Still, if we were targeting around 60°C (a 35°C increase), that would be just over half the heat output—about 2,400 watts.
We’d also have to think about the blower pushing air through it; even though it wasn’t powerful, it’s not a computer fan. So perhaps our two 160mm SP fans could only manage a third of the required airflow, leaving us with roughly 800 watts.
Given the small size compared to a typical 60mm thick 360mm radiator for water cooling, efficiency would be limited.
How do they manage it? By using turbulence—similar to why modern CPU waterblocks use dotted designs instead of fins.
Air side:
The design includes gaps in the air fins (about three times the spacing), which creates turbulence. This allows fresh cold air from the center to replace hot air near the fin.
It also uses 23 FPI with a very thin metal structure, zigzagged to resist bending while reducing air resistance.
Water side:
The core features a 3x12 grid of 4.5mm tubes instead of wide flat channels. This helps with manufacturing and maintains pressure better.
To improve heat transfer, plastic zigzags are added inside. This forces water to swirl around, increasing turbulence and helping release more heat. Plastic is chosen for cost and durability during movement.
The grid also causes air to swirl around the fin posts, creating horizontal turbulence—though this isn’t as effective as the slits.
As I understand it, manufacturers who make air coolers today would be better off using standard PC watercooling methods. Adding more features would just mean assembling components in a less optimal way.
TLDR
Heater cores from the 90s have advanced designs that boost turbulence and heat removal far beyond typical PC radiators, last longer under tough conditions, and offer better performance at lower cost.
Here’s a link to a similar example:
http://www.ebay.ca/itm/New-Heater-Core-C...if&vxp=mtr
AFTERTHOUGHT: After reading this, I realized it’s essentially a 23 FPI heatpipe air cooler with 36 tubes and coolant flow, plus turbulence elements to maximize heat transfer.
I also fixed the leak using jb-weld, tested it overnight at 20 PSI (1.4 bar), and it held together—so I’ll install it in my <$50 junkyard overclocker PC. It fits snugly between the side panel and the other side of my old 90s whitebox.
EDIT: I’ll trim a fin and check its thickness later, comparing it to a Radeon HD 4870 Dark Knight’s fins (found during another scavenger hunt).
Motorcycle radiators can also serve as excellent CPU coolers. Many of them include threaded connections, making installation simpler and safer. They tend to be more effective due to their compact design and increased durability from the demanding environments they operate in.
Condensation would explain why PC water coolers don't behave like car radiators.
Count Mike that's a good point. Although I'd imagine they'd be a lot more expensive (maybe not though).
EDIT: not too expensive on amazon, and they come in some interesting shapes (curved, angled in the middle, etc.). However I can't find any that use the fins-on-tubes arrangement.
James what do you mean by condensation? if everything is above ambient temp then it shouldn't be an issue?
I'm a bit concerned about heating up my GPU with this. (aircooled GTX 460 SE is going right by the output of this, and it hits 75 C with plenty of fresh cool air, So it may overheat when it's receiving 40-50 C air)
I might print some ducting to route air from this to the back of the case instead of emptying into the case.
For anyone saying it's weak, well I got it free and it overclocked from 648 to 925 MHz on stock cooling.
😀
plays CSGO on med/high settings 60 fps.
I've experienced heater cores before when using watercooling; they perform well, so the main concern is marketability. Newcomers to watercooling face a vast array of options for pumps, fittings, blocks, tubing sizes, and more than they realize what else could be used. The PC watercooling radiator design is designed to be user-friendly and aligns with standard mounting choices in most cases, such as common fan sizes. Automotive or cycling coolers follow specific requirements for their applications, while car and bike pumps are built for higher flow demands and may differ from PC radiators. This doesn't mean they won't work well in most situations—they often do.