Most efficient wood stove: 92% on three Klover models

Klover wood stoves declare an efficiency of between 85.2% and 92%. The highest figure in the range is 92%, declared by three models: VENUS 110s, VENUS 90s CLASSIC and KUOKI 110s. All three are declared in energy class A+, with the 5-star environmental certificate.

VENUS 110s declares 8.4 kW of nominal heat output on wood and a heated surface area of 95 m². VENUS 90s CLASSIC declares 7.7 kW and 75 m². KUOKI 110s declares 8.4 kW and 110 m². The figures apply under normal operating conditions, therefore with dry wood, a flue built to standard and a reasonably insulated home.

The other wood models in the range sit in a nearby band: MISS WOOD declares 85.7%, SWISS 85.6%, OLYMPIA 85.2%. Every wood stove carries its own efficiency figure on the technical sheet published on klover.it.

Efficiency is the share of the energy contained in the wood that the stove turns into usable heat. An efficiency of 92% declares that 92 parts out of 100 of the energy entering the firebox stay in the room, while the rest leaves through the flue with the smoke. This is the figure that answers the question of how much a wood stove consumes: for the same heat produced, a higher efficiency calls for less wood.

Nominal heat output is a different quantity and should not be confused with efficiency. The 8.4 kW of VENUS 110s is the heat the wood stove gives to the room under test conditions, not the wood burned in an hour. Real consumption depends on the species, on the moisture of the wood and on the air setting, which is why it does not appear as a single figure on the technical sheet.

On every Klover wood stove the combustion air adjustment is a single one: one control, on the front of the appliance, meters the air that feeds the fire. Keeping combustion steady instead of letting it run is the condition for real efficiency to come close to the declared figure.

VENUS 110s declares 8.4 kW, 95 m² of heated surface area and an efficiency of 92%. It measures 72x46x115 cm, weighs 165 kg and carries the built-in log store under the firebox. It is ready for double rear ducting, which takes warm air into more rooms, and for double front ventilation, available as an option. The finishes are Soap Stone and Matt Black.

VENUS 90s CLASSIC is the compact version of the same family: 7.7 kW, 75 m² and the same efficiency of 92%, in 72x46x78 cm for 145 kg. It has the large panoramic door with high-temperature ceramic glass, the same readiness for double rear ducting and a removable steel base.

KUOKI 110s declares 8.4 kW over 110 m² of heated surface area, again with an efficiency of 92%, inside a vertical architecture of 72x46x140 cm for 250 kg. Above the firebox sits an XXL stainless steel oven with three cooking levels. The finishes are Soap Stone, Nero Venato and Moka.

The combustion chamber of Klover wood stoves is lined with Keramik HD refractory. The material stores heat and keeps the temperature of the firebox high, which is the condition for wood to burn all the way through instead of leaving unburnt matter in the smoke. The same lining is declared on VENUS 110s, VENUS 90s CLASSIC, KUOKI 110s, MISS WOOD, SWISS and OLYMPIA.

VENUS 110s and VENUS 90s CLASSIC also work with the ember bed system, which according to the technical sheet keeps combustion constant and, on VENUS 90s CLASSIC, stable and clean with minimal emissions. They are two of the three Klover wood models that declare 92%.

The rest of the firebox is built to last: high-temperature ceramic glass closes the door and leaves the flame in sight, the handle is investment-cast steel and the flue outlet has a diameter of 130 mm on VENUS 110s, VENUS 90s CLASSIC and KUOKI 110s. On SWISS the declared diameter is 150 mm.

MISS WOOD is the Klover wood stove for the smallest spaces: 5.9 kW for 60 m² of heated surface area, in 50x54x75 cm for 125 kg, with an efficiency of 85.7%. Top and base are cast iron, the cladding is painted steel, and front ventilation is available as an option.

SWISS covers 80 m² with 8.7 kW and declares 85.6%. It measures 48.4x49.6x116 cm and weighs 145 kg. The cladding is high-density technical stoneware and the top is micro-perforated, a solution that favours the natural convection of air; the ash drawer is airtight. SWISS CORE declares the same 8.7 kW, 80 m² and 85.6% in 48.4x49.6x140 cm for 170 kg.

OLYMPIA reaches 100 m² with 9.4 kW and declares 85.2%, in 50x54x125 cm for 155 kg, with an enamelled cast iron top, a cast iron base and a stainless steel oven above the firebox. All these models are declared in energy class A+ with the 5-star environmental certificate. The full technical sheets are on klover.it, and a quotation can be requested from every product page.