Bearing in mind that i had to do recent repairs – as described in an earlier post – to the heater intake box due to a blocked drain hole. The air intake grill had some pretty large holes for air to enter the heater quite freely but the trouble is leaves etc get in as well then blocking the drain hole that is supposed to let rain and water exit to underneath the car.
The car came with a mesh fitted by a recent previous owner but due to the fine small holes restricts and reduces the air flow into the heater.
A compromise is the laser cut grill available from Alan Hinton which has holes small enough to block leaves but big enough to not restrict air flow.
The heater blower struggles to get any decent air flow so why make it harder!