Cleaning and maintenance

Painted hoods can be easily cleaned using warm water and dish soap. The same applies to our burnished copper hoods. Steel hoods must be maintained using specific steel cleaners, however for lighter everyday cleaning you can wipe them down using first a damp and then a dry microfibre cloth.

Care notes for PVD materials:
Never use abrasive cleaners on our high gloss PVD coatings, instead use a glass cleaning spray and wipe down with paper towels. Warm water and dish soap also work well on brushed PVD for tackling tougher stains.

The grease filter should be washed once a month. Fill the sink with hot water and dish soap or place it inside the dishwasher. Keep in mind, however, that this is a cleaning device and therefore food residue can stick to it. Many filters are made of aluminium, and can therefore get discoloured from using certain dishwashing powders. This does not affect functionality. Non-washable charcoal filters will need to be disposed of and replaced once a year.

Choice of motor

When you’re cooking, the fan should be capable of replacing all the air inside the kitchen 10 times per hour. You can easily find out the volume of your kitchen using this simple calculation: Length x Width x Height.

Take the following example:
The kitchen has a floor area of 3 x 4 m and a ceiling height of 2.40 m
3 m x 4 m x 2.40 m x 10 = 288 m3

In order for the fan to replace the total volume of air 10 times per hour, you would require a motor that ventilates approx. 300 m3/hour. However the specific installation must also be taken into consideration. The way the vents are installed creates back pressure, which in turn reduces the speed of airflow inside the ventilation system. The length of the air ducts needed and how many bends they need to make is also a factor who depend on how the duct is to be led from the kitchen hood and out to the outer wall. Finally, the valve on the outside wall is also important. Use only flap valves or backdraft dampers.

The following example gives you an idea of how the airflow is reduced:

A 1 m duct that’s 125 mm wide reduces capacity by 15 m3 / hr per 1 piece.
A 90-degree angle in the duct reduces the capacity by 35 m3 / hr
The valve on the outside wall can cause a reduction of up to 40 m3 / hr

So if our example kitchen uses the following installation: A 4 m duct with a single 90-degree bend, this produces the following reduction in airflow:
4 m duct = 15 m3/hr x 4 = 60 m3/hr
1 bend = 35 m3/hr
1 valve on outside wall: = 40 m3/hr
In total = 135 m3/hr
After these calculations, we now know that the kitchen fan should deliver a minimum of 435 m3/hr of airflow to ensure the perfect atmosphere to cook in

Sound level

How high should the hood be suspended?

The minimum distance above gas stoves must at least 65 cm to avoid any potential fire hazards. For induction ovens, the recommended height is between 50-70 cm, depending on the oven model and the height of the people who will use it. We recommend that our corner and suspended models are both easier to cook under if the hood is raised slightly higher than normal.

Good advice for installing suspended hoods

Choose a hood that’s wider than the stovetop. Increase the width of the exhaust duct from 5” to 6” (12.5 cm to 15 cm) if there is room to do so. Try to avoid adding extra bends in the air duct. Turn on the fan 5 minutes before you start cooking to create a vacuum inside the room. Leave the kitchen door open so that the fan has a steady supply of fresh air to use for ventilation.

Mounting u-shaped ducts on walls or ceilings

Screw two strips onto the wall or into the ceiling, so that they are fixed to the duct. Fasten the duct in place using screws placed into the strips and the exterior of the duct on both sides and in two places for each strip.

Mounting on sloping ceilings

The ventilation duct usually runs through the ceiling and out into the roof. Instead of slanting the metal duct below the ceiling, it is easier to extend the duct so that it can be stuck straight through the roof. The extension required will depend on the roof angle, but approx. 30 cm is usually sufficient. Use the roof joists or a cross-joint between them for a solid attachment for the duct

Energy consumption

A modern fan is usually not a major energy consumer in the home. But there are exceptions. An unnecessarily powerful motor will create a negative air pressure in the room that will require a free flow of air from outside. This fresh air must then be heated to room temperature, which requires extra energy. It’s important to find the correct balance between effective air ventilation and reasonable energy consumption. To help with the latter, all of our hoods have LED lighting that consumes 7 times less energy than incandescent bulbs.

Pressure loss / backpressure

The dimension, length and number of bends in the exhaust duct are crucial to how much of the electric motor’s capacity you actually use. By using a wider diameter of 6 inches (150 mm) you’ll better utilise the full capacity of the motor. The same rule applies to how the duct is shaped. The passage of the duct should be as smooth and straight as possible, and avoiding turns is best.

Absorption

Absorption is the fan’s ability to sort and capture any food particles from the kitchen air. All of our fans capture between 95-99%. A kitchen hood with good absorption capacity like ours doesn’t require as much air to create a fresh kitchen environment. Several of our models have a special section at the bottom, which helps to catch food particles even with small volumes of air.

Duct extensions

Always state the exact ceiling height when placing an order. Ducts for ceilings exceeding 290 cm tall are available on request. Prices will be quoted.

How to use a fan

Turn on the fan between 5-10 minutes before cooking. This creates a small vacuum in the kitchen, starting the circulation of air. If you wait too long after you start cooking and the kitchen is full of food particles, even the most powerful fan in the world will be unable to clean all the air in the room.
Close the kitchen windows, but make sure that the fan can still get a supply of additional fresh air, for example by keeping the door to the living room ajar.
Use the medium setting while cooking. If you ever need to put the fan onto its highest setting, your food is probably overcooked and needs to be rescued!
Use the lowest settings for ventilation after you’re done, for around 15 minutes

Brushless motor – energy efficient and super-quiet

Reducing energy consumption is important to all of us. In the brushless motors we use in our hoods, the carbon brushes that used to get worn out on other electric motors are removed entirely. The technology inside these motors also provides greater control of the motor speed, which in turn leads to a significantly reduced noise level in the kitchen. Simply put, the rotor acts like a compass needle, trying to correct itself to the ever-changing magnetic field. The action of the rotor is controlled by an electronic chip, which send pulses of electricity around the ring of coils that surrounds the rotor. It’s just like the crowd in a football stadium creating a rippling ‘mexican wave’ around the pitch. These pules create a magnetic field, which in turn spins a magnet in the rotor and controls its speed. A brushless motor like this guarantees significant energy savings combined with high recovery power: -85% power consumption (kW / hr) at medium-low speeds and -35% consumption (kW / hr) at higher speeds. As an added bonus, a brushless motor also has twice the service life of a conventional design.

LED lights

LED stands for Light Emitting Diode, and is a simple, efficient way for electrical energy to be converted into visible light. In a traditional bulb there’s a metal wire inside that warms up and begins to glow (and emit light) when electricity is supplied to it. Most of the energy is wasted to make this metal wire hot enough to glow. But with an LED, there is a small chip in a reflector array between two electrical points. This chip begins to shine when the power is on. A very small proportion of the energy disappears in heat, and an LED doesn’t need time to warm up before it can shine its brightest. Better yet, LEDs have a life span which is 50 times greater than that of a regular incandescent bulb. LED lamps also require very little electrical power and have excellent resistance to impacts and shaking.

The LED light bulbs in our hoods have a pleasant standard brightness of approx. 4000 oK, and a low energy consumption of only 3 W.
By investing in an efficient RørosHette (which combines a brushless motor and LED lighting) instead of a hood with a standard motor and halogen light bulbs, you’ll be saving the energy equivalent of 288kg of CO2 emissions per year! If you compare this to driving a car, it’s the same as saving yourself a drive of 1,747 kilometres – which is the distance between Kristiansand and Trømsø