Boxing in the top of wall & tall units

[The man with no aim]

Nearly at the end of our kitchen refit and I'm gonna box in the small gap at the top of our units, I'm gonna use additional plinths for this.

My question is, I need to leave gaps for the Oven and Fridge/Frezzer to breath as it were now, I've set the floor plinths 10mm below the underside of the units so as not to have those plastic grills. Do I slot cut the bottom (where fixed to the top of the tall & wall units) of the boxing in or do I shadow joint, leave say a 2mm gap to the ceiling.

I'm not sure which will look better and which will perform better, Fridge/Frezzer is 13amp supply whilst the oven is 20amp supply, they are in separate runs of units.

Thanks in advance.

Regards
T

[Job and Knock]

I'd say not, at least I've never felt the need to do that or to be called back later on. The amount of heat produced isn't so huge and most of it will dissipate into the wall behind (which will act like a heat sink) and along the service gaps along the backs of the cabinets. What do the manufacturer recommend?

[The man with no aim]

Neff recommend the full 300 square cms for the oven and Whirlpool 200 for the fridge/frezzer, we've got an overhanging roof to our bungalow hence, an air brick won't really work, which would have been simplist solution.

I'm currently thinking of using 150 dia. duct straight through the loft and out through the roof via tile vents, not cheap but, I know its gonna work, I've also fitted tile vents before as the loft is 1960's original felt lined.

Regards
T