A friend of mine is having a new heating system installed in his house and he is taking out all of the radiant heating system and installing a forced air set up. I was wondering if the cast iron radiators are worth keeping to use to heat a garage or something. Everything was functional when it was taken out. Seems like they would be a better solution than a air to water hx with a fan. Also can they use water down to say 100*F and still throw good heat? Thanks for any info. Kevin