It would be fine only if making Belgians. I would not even consider doing an ale, let alone a lager in it. Anale, you want to ferment in the low 60's, a lager in the 40's. 78* is just to warm to do much of anything in. As far as starting your beer at that temp, I wouldn;t do that either. You're better off to start your beer cool, and let it warm up to temp.
Can you maybe do a swamp cooler? But, I'm begging you, for the love of beer!!! Don't ferment at 78!