Just feel it and see what you think. I harp about cold because of a thread I was following when I first started. A guys plants were struggling and he was doing everything right. A very good grower was confused as to why. After several days the basement and it's cold floor was recognized. Water jug was bubbled on cold floor, they were getting cold water feeds Too! Your room sounds great. Just check the metal, if it's cold to your hand. Heaters may warm it nicely!