HUUM Rolls Out Air Tunnel Upgrade Across Its Entire Heater Line

HUUM, the Estonian sauna heater manufacturer known for its sculptural designs, has completed a significant but understated engineering upgrade. Starting in early 2024, the company made its internal air tunnel a standard feature across all HIVE models. The HIVE Mini followed in 2025. It's the kind of improvement that doesn't photograph well but matters to anyone who cares about heater longevity and steam quality.

What the Air Tunnel Does

The air tunnel is a structural channel inside the heater body that separates the heating elements from the weight of the stones above. This does two things: it improves airflow through the stone chamber, which speeds up heat delivery and improves steam quality when water is thrown on the rocks, and it protects the elements from being crushed or warped by the mass of stones sitting on top of them.

HUUM says the upgrade reduces heat-up time by roughly 15-20% and should meaningfully extend element lifespan, which has historically been one of the main maintenance costs for heater owners.

The upgrade also applies to HUUM's DROP series, the wall-mounted heater line that starts around $850 for the 4.5kW model. HUUM controls all heater connectivity through its proprietary UKU WiFi controller and companion app.

We believe the sauna heater should be the intelligence center of the room, not just the heat source.

Market Context

HUUM has been one of the fastest-growing heater brands in the North American market, built on a combination of striking industrial design (the HIVE's beehive silhouette is instantly recognizable) and competitive pricing for the quality level. The air tunnel upgrade keeps the exterior design unchanged while improving the internals, a move that rewards existing fans rather than chasing headlines.

Founded by Siim Nellis, a third-generation Estonian sauna heater maker, HUUM competes in the premium segment against Harvia, Narvi, and IKI from Finland and the TyloHelo brands from Sweden.