Pellet storage room


Matching our innovative boilers to the best possible storage solutions has been part of ÖkoFEN’s focus from the beginning.

This means we have unrivalled know-how and an unsurpassed range of solutions for adapting cellars and other rooms for pellet storage.


We can provide advice on every aspect of storage, from the correct amount of space for your system through to all-inclusive solutions with bespoke floor plans and automated pellet transport to the boiler.


1. Storage with vacuum suction system 2. Location of the pellet storage and the boiler room 3. Size of the pellet storage room 4. How do i fit up my boiler and pellet room? 5. Filler coupling with closing lid

The size of the storage room

The size of the storage room

The total heat load of a building determines the ideal size of the required storage room. As a rule of thumb, the following formula can be used: each 1 kW heat load = 0.9 m3 storage space (including voids).


In principle, it is better if the storage room is rectangular and no wider than two metres. The narrower the room is, the lower the inbuilt inclines will be and the more space can be used.

Sloping floor

Sloping floor

A sloping floor is the ideal configuration for a pellet store, allowing the space to empty completely. Not only does this allow for the maximum efficiency in feeding the fuel to the boiler, but it removes the need to clean the store room manually each year by avoiding a build-up of unused pellets.

With a sloping floor, the pellets slide to the delivery auger in the centre of the store. ÖkoFEN can supply angle brackets designed to give the optimum angle for a sloping floor substructure.

Keep clear of moisture

Keep clear of moisture

Ideally the storage room should be adjacent to an exterior wall. Should the storage room be internal the filler pipe and outlet pipe should be directed to the outer walls.


No light switches, sockets, lights or joint boxes should be installed in the pellet room itself.

ÖkoFEN Gewebetanks

ÖkoFEN Gewebetanks

Sie haben keinen passenden Lagerraum für Pellets zur Verfügung?


Kein Problem die Gewebetanks von ÖkoFEN sind nicht nur platzsparend sondern ermöglichen durch das Vakuumsaugsystem die optimale Beförderung zum Pelletskessel. Die Gewebetanks gibt es in 35 verschiedenen Größen und durch das Vakuumsystem ist eine Entfernung von 20 m Entfernung möglich.


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2. Storage with vacuum suction system

Pellet storage and heating boiler up to 20 meters away.

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3. Location of the wood pellet storage and the boiler room

Pellets are delivered by tanker truck and are blown into the storage room or the FlexiTank. The truck's pumping hose is max. 30 m length, so the filler coupling must be no more than 30m from the drive, parking space or road.


If possible, the FlexiTank room should border at least one exterior wall, since the filler coupling must be accessible from the outside. Where this is not possible, ventilation and filling pipes must be routed to a filler coupling on the outside of the building. (Attention - in some countries fire regulations must be observed).

<strong>Location of the pellet storage room</strong>

The boiler room should also have at least one exterior wall in order to allow direct ventilation. For boiler rooms which do not border an exterior wall, a ventilation pipe (at least 200 cm²) must be routed to an exterior wall.



Dry indoor conditions are a prerequisite, since the pellets would swell and became useless in contact with damp walls. In damply areas, we recommend to use our Flexilo textile silo.

<strong>The size of the pellet storage room.</strong>

Electrical requirements:

No light switches, electrical outlets, light bulbs and distribution boxes, etc. are allowed in the pellet storage room.

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4. Size of the wood pellet storage room

Basically, the wood pellet storage room should be elongated rectangular, with a room width - if possible - no more than 2.0 m:

i.e. W: 2 m x 3 m or 1,8 m x 3,2 m etc.

The narrower the room, the less unused empty space. The size of the required storage room depends on the building heat demand. The following rule of thumb may be applied:

per 1 kW heating load = 0,9 m³ Storage room (including unused empty space)


For example:

One family house with a heat load of 10 kW = 4.000 kg wood pellet annual requirement


10 kW heat load x 0,9 m3  = 9 m3 storage room capacity (unused empty space incl.)
9 m3 / 2,5 m (room height)  = 3,6 m2 storage room area
Recommended size  = 2 m x 2 m = 4 m2 storage room area
L x W x H x 2/3  = 6,7 m3 usable capacity (V)
V x 650 kg  = 4.355 kg wood pellets
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5. How do I fit up my boiler and pellet room?

Perimeter walls:
The surrounding walls and the ceiling of the pellet storage room and the boiler room should correspond to fire resistance class F 90. The enclosure walls must withstand the static requirements of the weight load of the pellets (weight load 650 kg/m³ aprox.). The storage room walls and their anchorage in the surrounding brick wall should be properly and professionally designed according to the rules of practice. Ceilings and walls are to be designed such that it does not come, through abrasion or delamination, to a contamination of the pellets.


Floor plan - pellet storage room


Sectional plan - pellet storage room 

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As with all other heating systems, the boiler room and the storage room doors must be fired proof (at least T 30). They must open outwards and fitted with a seal.
The pellet storage room door shall be provided -inside of the door opening- with wooden planks, so that the pellets do not press against the door.

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Sloping floor:

In order to empty the pellet storage room, it is necessary to install an sloping floor in the storage room. ÖkoFEN offer angle brackets to facilitate the construction of the sloping floor structure.

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6. Filler coupling with closing lid

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Filler coupling with closing lid:

The pellets are blown directly into the storage room and the discharged air is evacuated. This requires two "filler couplings" with a lid. (1 x blow + 1 x evacuate)

These couplings including extension pipes, curve pieps and other accessories, are supplied by ÖkoFEN together with the heating system. A wall opening with a diameter of 125 to 150 mm must be prepared on site. It is recommended to use a PVC pipe with a diameter of 125 to 150 mm fixed to the brickwork. The filling couplings are then foamed in the prepared openings. The filler couplings must be connected to the brickwork (grounding).

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