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EDR clarification

So I just finished reading "Greening Steam last night, and it made me question something I thought I knew about EDR.

So there are many things a homeowner can do to limit the heat they receive from a radiator. Paint it silver. Hide it in a radiator cover. Etc. But in describing the effect, we talk about how much "smaller" this makes the radiator. If you paint that radiator X color, you'd need a rad X% larger to get the same heat, etc.

My question is, do these actions really limit the amount of condensate a radiator generates, or do they simply limit the heat the homeowner recieves from them? Or both?

Yes, this <em>is</em> what I woke up thinking about. Maybe I should've waited for my coffee to kick in...




  • gerry gill
    gerry gill Member Posts: 3,078
    Both..it gets confusing

    but remember the first letter in EDR is the most important. Its Equivalent to direct radiation...what they would do is measure the condensate produced under various situations and extrapolate the data mathematically..attached is a picture John Shea sent me years ago of warren websters testing station..i can't remember where i heard this or even remember all of the details but i believe the original benchmark to determine edr was a column radiator 38'' high and i think it was two column but hopefully someone can chime in on that..but anyways ..when something is said to be equivalent to direct radiation, it would be that radiator they would be equivalent to..hope that helps..
    Serving Cleveland's eastern suburbs from Cleveland Heights down to Cuyahoga Falls.

  • Patrick_North
    Patrick_North Member Posts: 249
    Fun picture!

    Great picture!

    I was trying to wrap my head around situations where systemically increasing or decreasing a set of radiators could help or hurt efficiency. It seems like this could be done more easily with adjustable venting. If you have a single oversized rad, for example, throttling back its venting seems simpler, cheaper, and more predicatable. And if all of your radiators were equally oversized (but the boiler was sized to match) I’m guessing that it would be just as well to control things through venting.

    You might guess I’ve also been thinking about “Boilerpro’s”  article on sizing steam boilers to match heatloss, not necessarily connected EDR. Haven’t heard much about this idea lately- I wonder if others are applying it to good effect.


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