Second, the efficiency of an absorption machine increases with decreased generator pressure, but this is limited in practical work because a low generator pressure calls for cooling water of unobtainably low temperature.
Source: wiktionary
Unobtainably
Synonyms for "unobtainably"
Ranked by relevance and common usage.
Sample sentences
2 total sentences available.
They just seem more Romantic, more alluring, stronger and of course more unobtainably desirable when they stay alone.
Source: wiktionary