Originally Posted by Ultrasonic2 (muffy)
This is all in relation to this statement you made
"but to be honest a delta of 20% will get most people close to zero"
20% of 69c is 13.8c
your ambients would have to be pretty low to get you close to 0c
If your ambients were 15c that would make 1c which is close to 0
BUT my point was that the numbers your using while being correct dont account for losses in a real world scenario
which is what my pic was about theoretically the delta should be 50c in the pic but because of real world losses the delta is less and the hot side is obviously higher than ambient soo
20% delta wouldn't get him close to 0 in a real world situation
Im not arguing with you im merely saying he'll need more than 20% because of real world losses
and yes the sensors are on the hold and cold plates
There is this statement too
but as I have already said a delta of 20Âº will get most people close to zero
you actually said 20% but i doesn't really matter that much if it's 13.8c or 20c most people would have room temp around that or higher and the hot side will always be hotter than ambient and there's the losses i was going on about. pushing the load temps up
That was a typo.... you and I both know delta is ÂºC delta of 20% is gibberish.
OK maybe 20Âº was pushing the boundaries a bit say 25Âº then or are we going to get embroiled in another arguement on how far above ambient a hotside can be.
Why should the delta be 50ÂºC in the pic ? I am not with you.
Dtmax starts at 69ÂºC for most single stage TEC's as you reduce the power the Dtmax drops at subzero it is often helpful to stack TEC's because it increases the Dtmax.
Do you agree with the following ? You have stated this before so I know...
Depending how low the Dtmax drops will determine the maximum difference between the hot and cold sides at any given operating point.
the actual delta is determined by the temperature raised by the load on the coldside and the temperature of the hotside (for obvious reasons the ambient also affects the temp of both if they are exposed to it.)
So tell me why should the delta be 50ÂºC in your pic ? Are you saying the Dtmax should be 50ÂºC ? that would sound more reasonable.
If your saying the Dtmax should be 50Âº
The fact your delta is only 30Âº and not 50Âº is due to the hotside cooling. it is determined by the difference between the temperature raised at the coldside and the hotside temperature determined by your cooling, which is very good. (and the ambient.)Edited by zipdogso - 5/11/09 at 7:35pm