I don't know what chips you guys are using but given the range you really think you'll only have +/- 5% error through a 100 degree temperature range? Depending on the code written the unit could alarm continuously until it reaches 'normal' conditions or never alarm, without knowing the intention saying that this is 'fine' is jumping the gun. If the unit isn't in the air path of the fan it could be permanently stuck at the ambient of 0, this is fine if it's set for it, but if the chips temperature shifts I'm sure you'll get more than 5% error easily over that temperature range.
It might work fine on a cold day the day it was programmed and then when warmed up will alarm continuously, or worse if this does something besides control an alarm and actually alters some other portion of the system it would introduce a massive non-linearity into the feedback loop.
Another case of not enough information of what this will do, or how it will be used.