Narvi Kuru Woodburning Sauna Heater From Finland

1. INTRODUCTION

Thank you for having chosen a Narvi sauna heater.

To make the most of your sauna heater please read the manual carefully before you start installing and using it and keep the manual for future reference. This user manual contains the technical data of your sauna heater and installation, use and maintenance instructions.

The products are meant only to be used as a sauna heater and for heating the sauna. Do not modify the design of the sauna heater and use only spare parts and accessories recommended by the manufacturer. The data plate included in the delivery of the sauna heater must be glued on the sauna heater, preferably on the lower part of the cover of the sauna heater.

Do not heat the sauna heater if you lack sufficient knowledge, if you are not allowed to use a sauna because of your health condition or you are under the influence of substances causing intoxication. Sauna heaters must not be used by underage people. Do not leave children in the sauna without supervision. A sauna is not meant for drying clothes. Follow the instructions!

BEFORE YOU INSTALL THE SAUNA HEATER

Before installing and using the sauna heater, make sure you are thoroughly familiar with the requirements for installing the sauna heater in the steam room. In case of questions and for additional information do not hesitate to contact the Rescue Board or a construction supervision authority.

When installing fireboxes all local laws have to be followed, including those referring to local and European standards.

Sizing Your Narvi Wood Stove

If the walls of a steam room are made of uncovered glass, brick or concrete add 28–53 cu ft per square meter of such wall and the final choice of the heater shall be made based on the sum of the area. If the heater is installed in a sauna that is normally not heated or the sauna is made of massive logs, multiply the sauna area by 1.5 and choose the heater based on this. The recommended minimum area of a steam room is indicated in table 1. Please follow the values for the minimum area stipulated for a steam room. We recommend choosing a sauna heater with slightly more power to ensure proper heating of the sauna and to avoid heating the sauna heater to its upper limit. Slightly stronger power ensures a longer lifetime of the sauna heater.

Floor and Substrate

A firebox must be installed on the floor with sufficient load-bearing capacity. The durability of the floor must be checked especially carefully, when the sauna heater is installed on a wooden floor. The weight of the sauna heater is shown in clause 1.1. If the existing floor does not meet this prerequisite, suitable measures (e.g. load distributing plate) shall be installed to achieve it.

Concrete floor

The sauna heater may be installed directly on a concrete floor, which is at least 2 in thick. If underfloor heating cables or pipes are located under the sauna heater, a Narvi installation base must be used to protect them from the sauna heater’s thermal radiation.

Floor made of combustible material or a tiled floor, underfloor heating A Narvi installation base must be installed under the sauna heater, which will protect the floor, moisture barrier and underfloor heating pipes or cables from the thermal radiation of the sauna heater.

SAFETY CLEARANCES

When installing the sauna heater, safety clearances must be taken into account (1.1). Ignorance of safety clearances causes a fire hazard. If required, additional information can be obtained from the regional branch of the rescue board. 2.3.1

STRUCTURE MADE OF COMBUSTIBLE MATERIALS

The safety clearances (table 2) are the minimum allowable distances between the sauna heater and structures made of combustible materials. Please observe the stipulated requirements regarding walls, floors, sauna benches, other inventories and storage areas of firewood! Rear and side safety distances can be shortened by using Narvi protective wall shields. Our dealers can provide more info regarding suitable safety walls for sauna heaters. Protecting a wall made of combustible material If the sauna heater is installed on a floor made of combustible materials, Narvi installation base must be used.

A piece of sheet metal must be installed in front of the installation base, which extends at least 4 in over the sides of the heater hatch and at least 15.8 in in front of the sauna heater. The sheet metal edges facing the sauna heater must be turned up, so that coal cannot get under the installation base. Please observe that the safety clearance of an uninsulated smoke flue from structures made of combustible materials is 39.4 in or any other distance stipulated in the manufacturer’s instructions.

NON-COMBUSTIBLE STRUCTURE

If the wall is masonry or other structure classified as noncombustible, it is sufficient to have a 2 in air gap between the upright surfaces and the wall. If the sauna heater is installed inside a wall recess of non-combustible material, a 4 in air gap is required to ensure proper air circulation.

SMOKE FLUE

A smoke flue of the sauna heater must meet the requirements of class T600 irrelevant of the material of the smoke flue. The minimum recommended draft of the smoke flue is 12 Pa. A modular smoke flue must meet the requirements of class T600 and provided with CE-marking. When installing a modular smoke flue safety clearances stipulated in the installation manual of the smoke flue shall be followed. The minimum recommended diameter of a modular smoke flue is 4.8 in. The weight of the smoke flue must not cause load on the sauna heater. The sauna heater should be connected to a separate smoke flue. A smoke flue made of bricks must be at least the so-called half-brick smoke flue.

VENTILATION

Ventilation of the steam room should be sufficiently efficient and should function so that fresh incoming air is routed as close to the sauna heater as possible. Also proper air circulation has to be provided in the steam room during using the sauna so that air can exit from under the sauna bench or from under the door of the washing room (sufficient gap). Other possible fireplaces that are used simultaneously must be considered, and make sure there is enough replacement air. Extraction fans working in the same room as the firebox may cause problems. Incoming air inlets should be located so that they do not get blocked (for instance because of snow). A firebox needs combustion air in a volume of 212–353 cu ft per kilo of fired wood. The diameter of the ventilation opening must be at least 4 in. Forced air system should be built according to the design prepared by the designer of the heating, water and ventilation systems. After using the sauna there shall be a possibility to ventilate and dry the sauna rooms so that air exits via the upper part of the steam room.

INSTALLATION AND PREHEATING OF THE SAUNA HEATER

PREHEATING

Before use and arranging the stones, the sauna heater must be heated to remove the protective agents. Any protective films and stickers must have been removed before. Preheating shall be carried out on a non-combustible surface and outside, since paint emits harmful solvents and smoke during heating. Use of a connection pipe included in the delivery of the sauna heater in the upper joint improves draft during preheating. 1–2 fireboxes of wood are sufficient for preheating.

After preheating and before arranging the stones loose cover material should be removed from the stone compartment of the sauna heater with a steel brush. In case the external surface of the sauna heater is painted, it should not be rubbed or wiped before the first heating. The paint of the sauna heater will achieve sufficient strength only after the first heating.

Do not create steam during the first heating. NB! If the sauna heater is equipped with a water tank please check before preheating that the water tank faucet and safety plug are installed and that the tank is filled with clean water.

REGULATION OF THE HEIGHT

The legs of the sauna heater are adjustable and can be used for levelling the sauna heater and for adjusting the height. There must be an air gap of at least 1 in between the sauna heater and the floor.

FREQUENTLY ASKED QUESTIONS

The sauna heater is drafting poorly

– The sauna heater has not been used in a long time; the smoke flue and sauna heater are damp.

– The sauna heater is not receiving sufficient air; there is a downdraft in the sauna caused by ventilation.

– The sauna heater has not been cleaned in a long time.

– The ash drawer is closed or full of ashes.

– Leakage in the connective flue.

The sauna does not heat up properly

– The firewood is damp.

– The sauna heater has insufficient power.

– The sauna heater or smoke flue is drafting poorly.

– The stones of the sauna heater are dirty or crumbling or stacked too tightly.

– There are too many stones or there are too many small stones.

The sauna heater smells

– The sauna heater has not been properly heated the first time it was done.

– The stones of the sauna heater were not washed before loading.

– Fat or other dirt has accumulated on the stones.

– Steam water is not clean.

Installed: Off The Grid Lodge, north Georgia

A Narvi Kuru heating the cedar sauna at Off The Grid Lodge, a whole-home rental in the north Georgia mountains, the glazed door is the reason you can see the fire from the bench. Photo courtesy of Off The Grid Lodge; see the sauna it heats on SaunaShare.