Aluminum might be better, but wasn't around when cast-iron radiators
were first made. Iron is an excellent metal for casting and conducts
heat well (and is less expensive than other metals, like copper, that
are better conductors).
You were wrong, and I'm man enough to admit it.
I would imagine one benefit of a heavy cast iron radiator would
be the mass of metal will hold heat and release it over a long
period of time. I also think that a copper or aluminum radiator
of similar thickness would be prohibitively expensive.
Guess not. But, yes, you hit the nail on the head. The principal advantage of
cast iron radiators is that they retain heat very well, which provides a much
more even heat than the aluminum fin-tube radiators do.
I've read about the Scandinavian or Finnish style fireplaces that have a
huge mass of masonry which does the same darn thing. I've always thought
that if I were to ever build a home, I would want such a fireplace. Add
a bit of hysteresis to the heating cycle and keep things comfortable.
The only problem is they take a long time before putting out any real
heat. Maybe a fire all day until the mass of masonry gets hot. The
more mass, the longer it will take. Also the more mass, the more even
the heating will be.
Missing the point, both of you. The "lag factor" isn't an issue when the room
stays at a comfortable temperature all the time. It's apparent that you've
never lived in a home with a hot-water heating system using cast iron
It shouldn't be a problem unless you change the thermostat a few times
daily. And if you do, set the setting on your electronic thermostat to
change the high/low settings an hour ahead, or more or less to suit your
If your schedule is erratic, yes, stick to light weight copper/aluminum.
You have to do that anyway, with hydronic heating. However, it still matters
if you decide that it's too cold and ask for more heat. For homes, cast iron
has no advantages, some disadvantages (some major, some minor), and is more
expensive than copper/aluminum. It's got nothing going for it outside of
When we had a hydronic system (we have heat pumps now), we'd set the
thermostat to 59F at night, 64F during the mornings and late afternoons, and
62F during the day. If we were cold, simply crank the thermostat a few
degrees. The cycle would then restart itself. Eratic, yes. Programmed,
sure. Did I ever want cast iron? Hell no.
OK sure, cast iron is all hype like you say. There is no comfort gained
when using a heating system with a lot more mass. Just like there is no
comfort gained with hot water baseboard vs hot air. The copper,
aluminum, and mostly the hot water left inside convectors doesn't have
any more mass then hot air. Yes you are correct, no one likes hot water
baseboard more than hot air. Just because it has more mass than hot air
doesn't make it any better. You are right.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.