Nevermind the temp of the room...its the temperature around your plants you should concern yourself with.

Do you have central air?

If so...head to a hardware store, get yourself a aluminum exhaust hose. Typically they are in 8' lengths (once stretched all the way out).

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Remove the nearest vent cover, shove one end of the hose up into the duct work...secure it by wrapping a shirt or towel around the end...one to hold it in place, two to prevent cool air escaping through any gaps.

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Once its securely in place...you can bend, stretch, angle it in any direction you want it to go. Mine dumps it cold air right into the center of my grow area...with plants growing all around it. For additional cool spots...simply pop holes along the length in the areas you want cool air to be able to leak out of the sides of the hose.