"Steam systems are generally less efficient than hot water heating systems,
but the efficiency gain of upgrading to hot water is probably not worth the
I have heard this asserted just about everywhere universally, without a
single justification. Why is steam heat less efficient? Is it intrinsically
less efficient than hot water-based heating systems, or is it simply because
its typical installation is more wasteful? My guess is that steam is less
efficient because all the old steam pipes have had their asbestos insulation
removed and haven't been reinsulated since. Add to that the fact that steam
is much hotter and has less heat capacity than water and you have a recipe
for a very inefficient system.
But bad practice doesn't mean steam heat is less efficient.
And what about other types of home heating systems, like forced hot air? How
efficient are they? Does the energy source matter as far as efficiency goes?
Are oil-burning boilers/furnaces more efficient than gas burning ones?
Thanks zero. I've actually read a lot of Dan Holohan's stuff - he really
likes steam systems and has written much of what is available online about
| > I have heard this asserted just about everywhere universally, without a
| > single justification. Why is steam heat less efficient? Is it
| > intrinsically
| > less efficient than hot water-based heating systems, or is it simply
| > because
| > its typical installation is more wasteful?
| This address all of that;
They focus on industrial steam systems and how to improve efficiency. From
what I could tell, they do not address whether steam is intrsically less
efficient or whether the systems are poorly installed. Maybe you are
implying it doesn't matter. I think that is Dan Holohan's position.
| > My guess is that steam is less
| > efficient because all the old steam pipes have had their asbestos
| > insulation
| > removed and haven't been reinsulated since.
| Where has this happened?
Try Dan's other website -
| > Add to that the fact that steam
| > is much hotter and has less heat capacity than water and you have a
| > for a very inefficient system.
| That is opposite of the truth and incorrect at the same time;
| http://www.heatinghelp.com/newsletter.cfm?Id 7
From what I can tell, hot water systems operate around 200f. Steam is at
Specific heat of steam is half that of water. What I did not account for is
latent heat needed to turn liquid water into steam.
But it's ok if I am completely wrong - it was simply a guess on my part. The
point is, I am told definitively by the DOE that steam is less efficient
than hot water heat. I just wanted to know if this was true and if so, why?
| Spend a few days over at Google.com . It's all been asked/answered.
I have. That's a copout, zero. If you didn't know the answer, you didn't
have to reply.
If I had to take a really wild guess. It's cause steam needs to
be heated to a higher temp than hot water. 250 instead of 140 or
so. What happens, is that with a steam system the exhaust gaseses
up the flue are hotter.
With a 90 % efficiency hot air furnace, the flue gasses are so
cold they won't rise (naturally) up a masonry chimney.
A lot of the efficiency factor comes from extracting more heat
from the exhaust, and sending colder exhaust out. I've not seen a
90+ efficiency fuel oil furnace. Oil versus gas, well, it depends
on the design of the furnace. I've seen some gas furnaces that
are (probably) 60 or 60% efficient. But I've never seen a 90+ oil
Christopher A. Young
You can\'t shout down a troll.
I should probably take SM off my kill filter. Some of his posts are
just too funny.
FWIW, Chris, a steam system is about as efficient as any other 80%+
boiler in the dead of winter. Much less efficient in the spring or
fall. Why might that be?
You could be replaced by an infinite
number of monkeys.
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