SUNLU S4 or Comgrow SH01: the real filament-dryer value showdown

Display

This category is mostly about user interface and visibility rather than a literal screen quality spec, because neither product is being sold as a “screen-first” device. The SUNLU S4 wins here on paper because its feature set includes auto humidity control, which usually means a more informative and hands-off user experience. That kind of monitoring matters when you want to know whether your filament is actually drying or just sitting in a warm box. The Comgrow SH01 is more basic, and that simplicity can be a plus, but it doesn’t sound as polished or as feature-rich. Winner: SUNLU S4, because the smarter control system suggests a better day-to-day interface for checking drying status.

Performance

This is the big one, and it’s where the SUNLU S4 pulls ahead decisively. The S4 is marketed as a 4-spool filament dehydrator with fast heating and temperature balance, which points to a much stronger drying setup for people running multiple printers or lots of material. If you print frequently, switch materials, or keep several rolls in rotation, that capacity alone is a major advantage. The Comgrow SH01 is a filament dryer box and spool holder, but it’s aimed at a more basic “keep one or fewer spools dry” use case. It supports 1.75mm and 2.85mm PLA, PETG and ABS, which is useful, but the product positioning suggests it’s less ambitious in actual drying throughput. Winner: SUNLU S4, by a wide margin, for capacity and likely drying performance.

Build quality and design

The SUNLU S4 feels like the more engineered product. Auto humidity control, temperature balance, and “upgraded” 4-spool design all suggest a box designed for serious, sustained use rather than occasional drying. That matters because filament dryers live a hard life: repeated heating cycles, spool weight, lid sealing, and constant handling. The Comgrow SH01’s appeal is more straightforward: it’s a practical, no-nonsense box that does the job without a premium price tag. But at £42.74, it’s clearly positioned as the more economical option, which often means fewer advanced design touches. Winner: SUNLU S4, for the more refined and capable design.

Battery life

Neither product is battery-powered, so this category doesn’t really apply in the usual sense. These are mains-powered filament dryers, not cordless gadgets, so there’s no battery runtime to compare. In practical terms, what matters instead is how efficiently and consistently they maintain drying conditions over long sessions. On that front, the SUNLU S4’s fast heating and temperature balance features make it the stronger contender for long-duration use. Winner: SUNLU S4, if you interpret this as sustained power and consistency rather than literal battery life.

Price and value for money

This is where the Comgrow SH01 absolutely lands a punch. At £42.74, it is £42.25 cheaper than the SUNLU S4, which is a massive difference in a category where many makers just want dry filament and fewer failed prints. The Comgrow’s 4.4/5 rating from 3,225 reviews is also very reassuring: lots of buyers, lots of real-world feedback, and a solid reputation for doing the basics well. The SUNLU S4 is rated higher at 4.7/5 from 1,081 reviews, which suggests stronger satisfaction, but you are paying almost double for it. If your goal is maximum value per pound, Comgrow wins easily. Winner: Comgrow SH01, hands down, for affordability and strong review volume.

Game library/features

These aren’t gaming products, so there is no game library to compare. Translating that into maker terms, the equivalent is feature set, and the SUNLU S4 has the richer one. Auto humidity control, fast heating, temperature balance, and 4-spool storage make it the more feature-packed machine. The Comgrow SH01 offers the essentials: filament storage, drying, and spool holding for common filament sizes and materials. That’s enough for many users, but it’s not as comprehensive. Winner: SUNLU S4, because it offers more advanced filament-management features.

Overall user experience

If you want the easiest answer, it’s this: the Comgrow SH01 is the better buy for most hobbyists, while the SUNLU S4 is the better buy for power users. The Comgrow is cheaper, widely reviewed, and should satisfy anyone who needs a reliable dry box without spending a fortune. It’s the sort of purchase that makes sense if you’ve got one printer, a modest filament stash, and you mainly print PLA or PETG. The SUNLU S4, by contrast, is for makers who are tired of juggling damp rolls, want multiple spools ready at once, and value convenience features that reduce faff. Its higher rating and more ambitious spec sheet make it the premium pick, but only if you’ll actually use those extras. Overall summary: Comgrow wins on value, SUNLU wins on capability. For most people, the Comgrow SH01 is the smarter buy; for serious multi-spool users, the SUNLU S4 is the better machine.