Hair dryers / heat guns may be underengineered for the expected duty cycle and runtime. I've scratched my head about possible alternatives. A couple suggest themselves as starting points: 1) small resistance-element type room heater. 2) toaster oven elements. I think the latter may have already been mentioned in a previous post. (1) can certainly handle the runtime, and probably the duty cycle too. Could it get the oven hot enough? I suspect it wouldn't be a big problem, but it's a question. Probably best suited to an "outside the oven" type design. (2) is certainly robust enough to handle the oven environment and get it plenty hot, but might result in an oven with difficult "hot spots" -- and putting it outside the oven a la convection oven might make for an awkward build. Is there now some consideration of not recirculating or at least containing the heated air? The "heat budget" probably won't allow for just venting it when the fan is running. Cheers, Mark L. -----Original Message----- From: Lampe, Mattias SLC CT PEK <mattias.lampe@xxxxxxxxxxx> To: sugarshot <sugarshot@xxxxxxxxxxxxx> Sent: Mon, Jun 30, 2014 10:16 pm Subject: [SS2S-Main] Re: temperature controller with arduino Hi all, regarding SSRs, I have some spare ones I can send to Vicente, if needed. I don’t have much experience with thermal calculations and designs, but regarding the use of hair dryers/heat guns my idea would have been to NOT put the entire device into the oven – which indeed would cause some issues with the overheat protection and possibly melt some plastic parts of the devices – but to just use it to blow hot air through the chamber.