-------- Bob kb8tq writes: > I think you will find that things work out a whole lot better if you target > something > just above room temp. If your room runs 22 +/- 3 C , a set point of 27C > likely results > in better operation than 17C.
This decision should be based on expected abnormal situations. If your ambient might reach 35-40°C when cooling fails, running lower than ambient will cope, running higher than ambient will not. If your ambient might drop to -20°C when the heating fails or the lid is opened, then running higher than ambient is the robust thing to do. And as others have said: If you run lower than ambient, you have to plan for condensation. Bidirectional TEC setups need special attention: You have to take into account the 3:1 efficiency difference between heating:cooling, and only seldom, and then gently, switch direction, in order to reduce thermal stress in the TEC element. A sound bidirectional design use an inner oven to keep the payload temperature constant, and use a more coarse outer TEC loop only to keep the oven's operating conditions inside a narrow window. That way the TEC can operate with a suitably slow time-constant. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 p...@freebsd.org | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
