Can temperature fluctuations affect audio gear?

Magfan & Bigbucks, I'll say first that thermodynamics was definitely not one of the shining successes among the courses I took in college, but pending further info from Magfan's PhD friend I believe that Bigbucks is correct.

Magfan: In SS, for example, you have a max temp possible....say the junction temp of the devices. In a hot room wont' the difference drop as the room temp approaches junction temp? Or will the junction keep getting hotter until failure? Isn't there an upper limit to the temp of an amp?

The maximum rated junction temperature of a semiconductor device, less some derating (margin), is the maximum temperature that is safely allowable. It is by no means the maximum temperature that is "possible." And yes, it can keep getting hotter until its mtbf (mean time between failure) is severely degraded, or until immediate failure occurs.

Think of it this way: If everything has been turned off for a while, everything (including internal device junction temperatures) will be at the room ambient temperature. The energy that is fed into each device, less whatever amount of energy the device outputs to other devices, and less whatever amount of heat is conducted or radiated away from it, can only have the effect of heating the device up from that starting temperature.

Best regards,
-- Al

Let's straighten out the question? OK?

The OP wanted to know if heat was OK, and if the huge seasonal temp fluctuation was OK....
Well, I think we all agree that heat in excess is bad for electronics. Cold, especially condensing cold is perhaps worse....ZAP.

Heat cycling can also damage gear. Can Expansion and contraction of solder connections work them loose? Some of the new solders are less malleable than in years past. Wasn't that one of the problems with the X-Box?

Do we agree that cold air is better at sinking heat from electronics? It would seem that as the ambient temperature and temperature of the electronics got closer and closer, the amount of HEAT transferred would get less and less. It maybe that BigBucks is right, but I don't see it. The constant delta above ambient may work but I just see stuff getting hotter faster than the room it's in....especially if the room is externally heated...sunlight, hot day...etc. At some point, the junction temp of an output device would be nearing limits and be unable to dump enough heat.....thru all forms of shedding...radiation, conduction, convection....(others?) But would that be at a constant delta from ambient?

The electronics would raise temperature as the amount of heat soaked away got less but that would catch up to you at some catastrophically high temp....which would be a much higher temp that you'd like your room!

No matter the physics equities here, I still think that a room of 85f is WAY too hot for good electronics. Maybe just sitting there....OK, but I'd never run my TV in that hot a space. Or even my 'd' amp.

After living in the same house for 20+ years, I installed AC before last summer. Glad I did, too.

And Al, I agree with you, too. Starting from 'cold' stuff starts shedding heat as stuff warms. Convection. Conduction. Radiation. All play a part in shedding heat. However, that heat goes somewhere. A bad / Extreme example is my RPTV. It kicks out a jumbo amount of heat. That lamp COOKS. Well, it sort of keeps the house thermostat artificially WARM. The TV is about 6' from the thermostat. The rest of the house cools and gets downright cold.... But that TV warmed thermostat says that all is well.

I don't mean to play the 'expert' card, but I will call my physics buddy. He is a hi-end semiconductor engineer and should be conversant with these issues. I'll ask and post back..Give me a couple days. If I have to buy him lunch, I'm billing you guys for 1/3 of the bill....each! just kidding.

Elizabeth,
You could make a decent case for me being about 1/2 gene away from washing my hands 30 times a day.
Heat DOES kill electronics, no question about it. The devices most prone to heat effects are power devices, which obviously use plenty of heat sinks. ICs can cook, too, some of which have extremely high circuit density. The proof can be found in any semiconductors 'reliability' testing program where devices are tested to failure.
For example, modern multi-core CPUs will dissipate maybe 70 watts? Maybe more...maybe less, I'm not current. I know voltage requirements for some devices has dropped to keep power down. And look at the obsessive lengths some computer modders go to ensure proper cooling.

I'm waiting for a passively cooled class 'a' amp with heatpipes or maybe liquid cooling, chiller and pump.

That being said, such shorter lifespan for hotter stuff has a statistical base. Silicon based semiconductors simply don't like temps much above....say 150c which depending on how much power you're talking about may actually kick out quite a bit of heat. Example:: A Penny at 150c has a lot less heat energy than say......an anvil at room temp. A power transistor running hot in a properly designed situation....proper thermal contact and enough heatsink area and mass, will get the heatsink pretty warm.

The observation you may want to make is how hot is the EQUIPMENT in your 80f room? If the gear is in an enclosed space with poor or marginal ventilation, your 'goose' is cooked and you may just be lucky. OTOH, if your stuff is in a well ventilated space and is the good gear I know you like, than you'll be fine. Even Bryston can be cooked. They design stuff with the 'noise' of actual use in mind. If EVERYONE used the amp in a cool, well ventilated space, they wouldn't use as much heatsink. But, they were thinking ahead. You are in the normal, expected range of users.