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two vents on a small radiator?

I have a pair of small radiators in my sunroom to ward off the cold from the windows. in reading 'the lost art...' i saw that you are not supposed to vent radiators at the very top because the vents will close before all the cold air can get out. these rads only have ports at the very top and very bottom. i notice now that the top of the unit is much much hotter than the bottom. does it make sense to add a small vent to the bottom as well to let out that trapped air? I have a few extra Hoffman 40s sitting around that I would use. see pic.


  • bradslees
    bradslees Member Posts: 34
    oh yeah

    also, these are at the end of the main. the last two risers. they get hot just fine and behave normally, just only get really hot at the top. no other issues.
  • steamedchicago
    steamedchicago Member Posts: 72
    room warm?

    Is the room comfortable?  If it is, you don't need to do anything.  If it's not, then maybe adding another vent would help.  it looks as if there's a boss about a third of the way up on the valve side; if so, there's surely one on the vent side.  You can remove the plug, or drill it out and tap 1/8 NPT, if it's not already drilled and tapped, and install the vent there.  
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