As suspected, the Spec-01's lack of an exhaust fan is detrimental to temperatures, especially the CPU, which peaks at a delta of 59°C, one of the highest we've seen. By comparison, both the Antec One and NZXT Source 210 Elite ship with an extra fan and have both of their fans mounted as exhausts around the CPU area and achieve temperatures that are better by over 10°C. That said, the Spec-01's ventilation around the CPU does help it out a little, as heavily insulated cases like the Nanoxia Deep Silence 2 can reach even higher CPU temperatures with low speed fans.
Click to enlarge
The GPU is fed cool air by the single front intake, the airflow from which is effectively unimpeded. As such, while the 49°C delta T for the GPU isn't the best (the Antec One and NZXT Source 210 Elite still fare a little better), it's perfectly fine, especially given that the front fan emits very little noise indeed.
Ultimately, assessing the Spec-01's cooling potential is all about your own hardware configuration. If you're running an LGA1155 or LGA1150 CPU at stock speeds, then with any half decent cooler it's not going to be an issue. However, if you're pushing for hefty CPU overclocks you might want to move the intake fan into an exhaust position or buy an extra one (or use a spare), especially if your GPU also dumps its heat into your chassis rather than directly out of the rear I/O panel like ours. Even a basic mid-to-low speed 120mm fan will help a lot without driving up cost or noise too much.
Click to enlarge
Corsair's approach to its most affordable chassis yet has been one of getting more of the basics right, and it's been largely successful in this approach. Expecting heaps of water-cooling support or more exotic features like fan control is unreasonable in a sub-£40 chassis, but with USB 3, a removable drive cage, an LED fan and excellent attention to detail throughout the Spec-01, Corsair has built a very well-rounded budget chassis with enough expansion room for storage and cooling to keep most people happy too.
Though NZXT's Source 210 Elite has better cooling, it now appears to be out of production, and its lack of dust filters and SSD support is problematic too. The Antec One, however, is still being sold. It does cost £5-10 more, but it has better cooling than the Spec-01 thanks to its dual exhaust fans, as well as an extra USB 3 port. On the other hand, its non-removable drive cage makes longer GPUs a tight fit, and it's not as easy to work with as the Spec-01.
The only real issue, and it is a rather big one, is the Spec-01's CPU temperature - it's likely an exhaust fan would massively improve the situation, but as we test out-of-the-box performance, sadly the Spec-01 misses out on an award as a result. If you're okay to add an exhaust fan, though, then this would likely make this one of the best sub £40 cases out there.