Source, Edward Nunn, Hatco Corp.
Concerned and confused about ventilation requirements for drop-in induction units?
Induction units do not generate much waste heat, but they do generate some. It is not really from the cooking or warming side of the top surface – nearly all that thermal goodness goes into the food in the pot, pan, or serving vessel. The troublesome heat generated is from the unit drawing in air to cool the electronics inside. A bit like a laptop does, really.
For countertop units, this is a concern when they are used in a commercial kitchen, but not so much for ‘out front’ display cooking applications. However, for drop-in (built-in) applications, this is a really important thing to consider. Overheating can lead to an induction unit shutting down, or worse, complete failure. And of course, that will happen at peak service time!
So, we are often asked about cabinet ventilation requirements and it is a tough question to answer. The simplest answer is ‘as much access to free air as possible.” But of course, that may not be practical nor meet the dining space aesthetic expectations of the end user.
‘Thermal vulnerability’ varies massively between the many brands and few actual manufacturers of induction cooktops and warmers. At the low end, some units will only tolerate 90°F, which is remarkably low – especially for a unit targeted for installation in a relatively closed-in cabinet. Extra cabinet fans may be called for and presumably interlocks must be installed to prevent the units from being used without those fans running. In the mid-range, ‘snorkels’ of conduit are required to prevent units from re-ingesting their own warmed exhaust over and over. At the upper end, no additional fans are required, and the basic ventilation requirement is free access to air from outside the cabinet. The total surface area should generally match the total surface are for the intake and exhaust vents for all of the units installed, usually divided into two (front and back of the cabinet for intake and exhaust), but ‘against wall’ cabinets can be accommodated too (provide ventilation top and bottom on the serving side). Owner’s manuals provide the detail.
The attached calculators are handy for determining ‘heat gain to space,’ i.e. how much heat will build up in a cabinet. Simply fill in the blue boxes. The green boxes can be changed but are set for Hatco products. The results are shown in yellow at the bottom. You can hold competitors’ feet to the fire here too – use their max ambient data!
Each has two tabs (standard units and metric units). There is one for warmers (hold-only low power units) and one for cooktops. The reason for having two is that the ‘usage rate’ varies greatly between the two applications. We hope this helps!