Kitchen plinth heaters - how much space do they need for airflow

[volks]

Recently redid my heating and had a plumbed in plinth heater fitted in my kitchen. Due to plumbing limitations, it's inside the bottom of a cupboard instead of under a kitchen cupboard.

There's about 4cm gap between the top of the fan and the shelf above it. I notice if I lift the shelf while it's running the fan slows. I wonder if the gap is too small and is restricting the airflow?

There are intake gaps in the front grill so it should be fine, but wanted to be sure before I risk damaging it.

See attached for style of heater and the final fit of the shelf above it.

 

[Justin Passing]

Can't see you damaging it.

It's not the sort of fan which gets slowed by lack of airflow. Sure it's not just the sound changing, giving the impression?

 

[volks]

Can't see you damaging it.

It's not the sort of fan which gets slowed by lack of airflow. Sure it's not just the sound changing, giving the impression?

It could be, yeah. I just assumed as the sound changed to a higher pitch it was somehow impacting the airflow of the fan. I'll check by waving a tissue in front and see if it moves more or less.

 

[Harry Bloomfield]

There's about 4cm gap between the top of the fan and the shelf above it. I notice if I lift the shelf while it's running the fan slows. I wonder if the gap is too small and is restricting the airflow?

That is because with inadequate air flow in, the fan blades are running in a partial vacuum, less dense air. That confirms the input air is not adequate.

 

[volks]

That is because with inadequate air flow in, the fan blades are running in a partial vacuum, less dense air. That confirms the input air is not adequate.

Thanks for the insight! So ideally I need to allow more air into the space to get a better airflow out of the fan?

 

[Harry Bloomfield]

Thanks for the insight! So ideally I need to allow more air into the space to get a better airflow out of the fan?

Yep - either greater spacing, or some form of hole or vent through the shelf.

 

[foxhole]

The vents to the front provide all the required air flow.

 

[volks]

The vents to the front provide all the required air flow.

I did think that too! Did some testing by blocking the air vents at the front with tissue then lifting the shelf until the air flow no longer went via the vents.

Maybe it isn't an extra hole needed, but a greater cavity for the air inside to circulate?

 

[foxhole]

I did think that too! Did some testing by blocking the air vents at the front with tissue then lifting the shelf until the air flow no longer went via the vents.

Maybe it isn't an extra hole needed, but a greater cavity for the air inside to circulate?

It’s fine as it is .