“I’ve chosen a stove that has both a top and a rear flue connection. Which one should I use? Does it matter, or does the stove heat better with one of them?”
At first glance, it seems to be just a matter of the flue pipe’s location. However, the connection method can affect the chimney draft, the cleaning of the flue pipe, and the stove’s placement options in the room.
An exhaust pipe at the top or rear is not automatically better. The specific chimney and the type of connection are crucial.
How does the upper smoke vent work?
The exhaust gases from the oven exit upwards at the upper outlet.
With suitable positioning of the chimney, the smoke extraction can run largely vertically, without unnecessary changes in direction.
This is particularly advantageous with regard to resistance to the exhaust gas flow.
Each angle of curvature represents a specific pressure loss.
The upper outlet can therefore be more advantageous, especially where the chimney draft is weaker or where a simple and short connection can be made.
How does the rear smoke vent work?
The rear outlet directs the exhaust gases out at the back of the oven.
If there is a suitably placed flue behind the stove, a short connection can be made directly to the chimney.
However, if the flue is located higher, it may be necessary to use an elbow or other flue pipe components.
The rear outlet is particularly popular when the customer does not want a visible pipe above the oven.
However, this does not mean that the oven can automatically be placed close to the wall. The prescribed safety distances must always be observed.
Do stoves with a flue pipe at the top have a better chimney draft?
They may find more favorable conditions, but that is not always the case.
If the upper outlet allows a more direct path with fewer bends, the flow resistance of the flue gases is generally lower.
However, the entire exhaust system path is crucial.
For example, a short rear connection to a suitable chimney may work better than an unnecessarily long and multiple-coiled flue pipe originating from the top outlet.
The oven manufacturer MORSØ also states that in poor draft conditions, a connection from above may be more advantageous.
It is not only the location of the outlet that matters, but above all the actual path of the flue gases.
Will a stove with a top vent produce more heat?
The upper outlet alone does not increase the rated power of the stove.
If the manufacturer allows both connection options for a model, this does not mean that switching to the upper connection will result in a more powerful stove.
A visible flue pipe can release a certain amount of heat into the room.
However, this is no reason to intentionally lengthen the chimney flue.
Excessive cooling of the flue gases can worsen the chimney draft and promote the formation of deposits.
Which electrical outlet is better suited for cleaning?
This depends on the design of the flue pipe and the accessibility of its individual parts.
For optimal connections, a simple cable with as few elbow fittings as possible can be advantageous.
For the rear connection, it is important to be able to clean the horizontal section and any changes in direction.
In some cases, therefore, an angled piece or a T-piece with a cleaning opening is used.
The exhaust system must be able to be safely cleaned and inspected, regardless of the chosen outlet.
If the stove has two electrical outlets, can I use one of them?
If the manufacturer of a particular model allows for both a top and rear connection, you can usually choose the option that fits the prepared exhaust path.
However, this does not mean that both sockets can be used simultaneously.
Unused electrical outlets must be properly closed in accordance with the oven’s design and installation instructions.
On some models, the flue and the cover cap are repositioned when the flue is replaced.
Such settings may only be made in accordance with the manufacturer’s instructions.
So, which distribution channel should we choose?
| situation | Things to consider |
|---|---|
| The chimney allows for a direct vertical connection | The upper socket could be more practical. |
| The stove is located directly behind the oven at a suitable height. | A rear outlet can be practical. |
| The chimney draft is weaker. | The path with the least resistance might be preferred. |
| They don’t want a visible pipe above the stove. | A rear outlet might be more aesthetically pleasing. |
| The stove has both electrical outlets. | The manufacturer’s instructions and the specific installation guide are decisive. |
What can you take away from this?
The upper and rear smoke vents are not just a matter of design.
Your choice influences the type of oven connection, the number of pipe bends, the resistance to the exhaust gas flow, and the accessibility of the exhaust pipe for cleaning.
With a straight vertical line, the upper outlet may be more advantageous, while the rear outlet may be more advantageous with a suitably positioned flue pipe behind the stove.
However, neither option alone guarantees better heating performance.
Before making a decision based on appearance, check the location of the chimney, the requirements of the stove manufacturer, and the possibilities for a safe connection.