Why hot water and not steam?

ChrisJ

I'm just curious why many modern homes (1940s and up) use hot water heat instead of steam.



I've seen quite a few posts saying steam heat when configured correctly is more efficient than forced air and even hot water.  If this is so, why isn't steam more popular or even existent at all in newer homes?



I know why forced air is popular, its CHEAP to install.  But hot water isn't any cheaper to install than steam, is it?



What are the pros and cons,  steam vs hot water?



As many know, I'm 100% for steam,  I'm simply trying to expand my knowledge and understand the whole picture.

BobC

cost

Threaded steel pipe is a lot more expensive to buy and even more expensive to install. Builders are VERY sensitive to costs.



Bob

gerry gill

pretty much

just cost...water could use smaller copper pipes..and copper was much cheaper back then.

Steamhead

One big advantage of steam

is that it won't freeze up in an extended fuel or power failure like hot-water can. Except for some pipes in the basement, and the boiler itself, the system drains dry when it shuts off.



But steam does not tolerate poor workmanship. And builders in general don't care about workmanship as long as they get their money.

Long Beach Ed

I Love Steam

...and I know how wonderfully steam can work.



But by varying the temperature of the water, a well designed hot water heating can do the job more efficiently than steam.   Water is also easier to zone, and much easier and cheaper to buy and install.



The lower the temperature of the heating medium, the lower the standby losses. 



Which is why steam heating is outlawed in much of Europe,and why many municipalities will not permit the installation of new steam heating systems here in the USA.

The Steam Whisperer (Formerly Boilerpro)

Ah, But Gerry has addressed the cost issue..

with his minitube system.  Small copper pipes, much smaller radiation than hot water.  I believe the biggest issue is apathy or belief that steam is not in the future by boiler manufacturer's.  There is zero marketing on thier part, yet nearly all of them have good people that know that steam can't be matched in performance in most ways.  

 I've begun marketing steam as a high efficiency and comfort alternative in the past few months and already have 3 homeowners that want to convert to steam from forced air and a number asking about converting from water to steam. 

 As Steamhead said, (with no disrespect for those here that truly know the hot water trade), steam requires better training to have it work properly, where hot water is much more forgivng of incompetence.

1. The manufacturers, AND WE, need to begin pressing the Dept of Energy to change their testing methods that inherently give greatly inflated efficiency numbers to forced air heating and A/c and to a lesser extent hot water heating equipment and inherently undervalued numbers to steam equipment.  Thier testing is not only flawed, but ignores system dynamics and how they interact with buildings and people. 

The Steam Whisperer (Formerly Boilerpro)

Steam outdoor reset.....

steam temperature can and has long been varied in temperature. 

Steam is as easy to zone as hot water when considering how it is done in Europe (TRVS). 

 Standby losses can be very low with steam since it has very little mass compared to water  (1lb of steam carries the same amount of heat as 50 lbs of water in typical systems, 100 lbs of water in typical radiant floor systems).    

Steam can use the same size copper pipes and much smaller radiation than hot water.  I

It also can respond nearly instantly, like forced air, but still provide very stable comfort under steady loads. 

Steam also uses a fraction of the amount of eletricity as hot water since no pumps are necessary for circulation, making it much more efficient in the use of our least efficient energy source.

Steam is easier to  make repairs to the system because little or no water needs to be drained. 

Like Steamhead said, no freezing issues.

ChrisJ

help?

Is there anything I and other home owners on the wall can do to help the future of steam?

ttekushan_3

Hot water circulator and small copper piping

In addition to all that's been said, I think the hot water circulator and the ability to use small copper piping that didn't have to hang low from the ceiling that did it.  We can't ignore the fact that the advent of forced air (instead of gravity) was changing everything and was the cost standard of the post war building boom.  And this happened before the widespread use of air conditioning.  The "new and improved" hot water was the only wet heat that stood a chance from a 1st cost perspective as compared to the "new and improved" forced air system.  The home I live in has early forced air (1939) yet there are a few (very few) houses of the same type and vintage in this development that had the optional Steam Heat Upgrade. 



But steam was viewed in that transitional era as being the system with the big expensive steel hanging (and banging?) pipes that screwed up plans for the "new and improved" knotty pine basement rec room.



No one wanted the pipes and no one wanted to twist that pipe.  Unfortunately, the Iron Fireman SelecTemp copper tube steam heating system came too late in the '50's as I think the tide had already turned.  As boilerpro pointed out, the minitube system (like Gerry's) is actually easier to install than HW, but I think SelecTemp's proprietary steam turbine driven unit heaters priced them right back out of the ballpark.



But steam got bumped out of the market so long before condensing technology existed that I doubt "efficiency" was what pushed it out.  When I was growing up, my dad the architect always viewed steam heating as a very efficient system in its day. 



It was cost and prevailing view of how it had to be piped (BIG) that did it in, IMO.

----------

Regarding heat loss in pipes, I've often wondered if anyone takes into account that the heat loss from steam lines is primarily from the main and runouts, but not the return; and that the supply and return on a hot water system are nearly the same temperature with similar heat losses.  This is, of course, because hot water releases so very little heat into the room (including the radiator) for the amount of mass circulated as compared to steam.  Just askin'



I've never bought into the whole idea that steam is so difficult to control.  If you use TRV.s or, like in the old days, pneumatic thermostats, I see no problem.  I guess I've been privileged to have been exposed to steam heating systems both large and small that were working as designed.  Believe it or not, I never heard a steam system "clank" until I started working in the steam biz.  The bigger systems at my school all had room thermostats and modulating burners on the boilers.



And as Steamhead said, the steam heating systems can tolerate freezing. I know that my school's system would shut down towards the end of the school day.  They had those classroom ventilators, and I'm told that that stuff regularly went below freezing over weekends and Christmas break.  



In the rustbelt here, the number of foreclosures in recent years has exposed this achilles heel of hot water heating.   I have witnessed the demise of a disturbing number of hot water systems due to freezing.  Many times the Bank's winterizing service showed up after the damage was done.  So far the steam systems have survived.

Steamhead

Ed, have you actually run into

"municipalities (that) will not permit the installation of new steam heating systems here in the USA"?

Long Beach Ed

New York

The New York State Energy Code requires all new home installations to have Annual Heating Efficiency ratings of 90% or better.   There is no exception for steam boilers in new construction. 



I doubt a plan examiner would know the difference if I submitted plans for steam as long as I included the required heat loss calculations.



Code enforcers usually (but not always) want a print-out from a combustion analyzer showing no less than 90% when they sign off on the job.  On existing systems, steam boilers are exempt, but even a new hot water boiler in an existing home must meet this requirement.



I don't see how we could install a new steam system in New York and get the 90% sign-off. 

Charlie from wmass

I like steam but water is cheaper to install new and

water is more efficient then steam heat. If the building already has a steam system the efficiency savings do NOT out way the cost and trouble with converting to forced hot water if the majority of the system is still in good working order. Steam makes sense if you already have it but not as a new system. This is all depending on equal quality of workmanship and attention to details for both systems. The Fire man system could turn this on it's head, but only time will tell.

jumper

steam can be less expensive

I've seen multi-unit residential buildings where the steam system was substantially less expensive to install than hot water. One pipe and that pipe was light wall. Manual feed. A central air evacuator instead of terminal vents.



The designer installer switched to hot water for several reasons. Officials did not like unconventional. Steam installation requires more care,especially when chase for the riser is far from exterior walls.

ChicagoCooperator

Flexibility of fuel source favors hydronic....

I think the flexibility of fuel source has favored hot water systems - I can't see using anything but gas or oil for steam boilers (wood seems like a hassle for steam). Plus people wanting to live "off the grid" will favor such sources as geothermal, exhaust air heat pumps or wood for hot water boilers. The sources of innovation in heating in Europe have favored non fossil fuel heating lately as well due to uncertain availability of gas from Russia (and some countries never used gas or oil at all - Norway is pretty much all electric resistance heating - it's cheaper there than wood). With the passive house movement there is very little demand for heating and what there is comes from heat pumps on exhaust air, which is where the innovation has been.



We should also keep in mind that the gravity hot air furnace has a long tradition in America and was more widespread for single-family housing than steam or hot water well before air conditioning was available, but once you could have heating and cooling in one system the choice was obvious. Not that it was a better choice for heating, just a reasonable one.

ChrisJ

Wood and coal

I would assume steam would be great with wood and coal. You can heat the whole house without any electric or moving parts and much smaller piping and radiation than with gravity hot water.



Why do you feel steam would be a hassle with wood?

ttekushan_3

Steam and non electric central heating

Steam for central heating prevailed before there were gas and oil boilers. It was used when all we had were "alternative fuels." The same stuff as used in heating stoves.



Simply stated, larger scale Central Heating required efficient and effective distribution that gravity water and gravity air could not do. Notice that homes with gravity hot water are tall but narrow. Hot air and gravity water were not scaleable without electricity.



Steam heating boilers are also power boilers since distribution is fueled by expansion of water to steam about 1700x (and vacuum induced at radiators by the same factor). Nothing else can do this but a phase change. Electric pumps and blowers removed this advantage of steam, and this advantage has actually been used to knock steam since the motive force is removed from the efficiency equations relating to boilers and furnaces. Heating water under pressure at 215 degrees (and circulating tons of it) is not the same as heating water to steam at 215. The physics if different, but is gleefully ignored by the industry. This is how some steam systems like Gerry Gill's minitube system uses a small amount of fuel that belies the comparative ratings on the boiler.



So if we assume a continuous supply of free electricity, well, then I guess we don't need steam's motive force for self distribution. If we also assume that manual feeding of alternative fuels into heating devices is "easy" with water and air, but "difficult" only with steam, then I guess steam's completely out of the picture. And if complexity is simpler than simplicity, I'm moving to a parallel universe!

ChicagoCooperator

Coal/wood storage

You have to store up a lot of wood or coal and then feed it into the hopper/stoker. If you have oil or gas you just have a tank either with a pump or under pressure, so you need to do either a) manually feed it b) have an electric stoker or c) a mechanical stoker. I grew up in a building which originally had coal fired steam and read the minutes in the mid-60's when they replaced the boiler with a gas boiler and read the raving about how much easier it was, no stoking, heat all night, warm in the morning, etc.



In addition wood and coal aren't as clean burning. The way codes and expectations of building tightness are evolving, certainly in new construction, steam and even hot water's days are limited. Hot water heating or even gas appliances would overheat a passive house and there are combustion issues (of course the boiler could be outside the sealed envelope) within the tightly sealed building envelope. 

ChrisJ

I see

The way you wrote it, it seemed as if wood was fine for other forms of central heating but not steam.



Those characteristics of wood and coal are the same across the board.

jumper

alternate universe

Terry I think we were moved to the parallel universe decades ago.

Your comment about gravity hot water being problematic for larger buildings is too true but turn of the last century mansions in Toronto were hot water more often than steam. Must have been much more expensive because they had bigger radiators and way more pipes.

stevep

Danger

Steam is more dangerous than hot (more like warm) water in the event of an occupied boiler room failure (think nasty burns). It's much easier for a water system to pass a home inspection since it's much less complex than steam.



It's also my belief that a properly installed water system will completely drain to boiler level if the plumbing is pitched properly, so frozen pipes should not be an issue for a quality installation.



Don't get me wrong I love my steam system, but it takes a tinkerer to maintain it.

Steamhead

Ain't necessarily so

Hot-water boilers can explode and pipes burst..... and since a water system runs under more pressure than steam, the resulting release of scalding water will travel farther.



Heating boiler explosions are rare these days, but the last few I've heard of were hot-water rather than steam.

ChicagoCooperator

Another reason for steams "demise"...

I suspect that the advent of the slab on grade house, particularly in norther climates, hastened the shift away from steam systems.



Have been having fun mulling over this from time to time..

jumper

somebody messed up

Homes built in the twenties. In Montreal steam. In Toronto gravity hot water. So I figure that a long long time ago somebody messed up in Toronto to give steam bad reputation there. For homes anyhow. Otherwise hot water would never have been invented. Double the pipes,double the fittings,double the work.

Stick

The difference in fuel consumption to produce steam, versus hot water is astronomical! To heat one pound of 60 degree water to 180 degree water is 120 btu's, and that's a nominal temp for baseboard heat. To heat one pound of 212 degree water to produce 212 degree steam, changing states from liquid to a gas, requires 941 btu's!!! That's not even counting the btu's to get the same 60 degree water to 212 degrees in the first place! The other component to this is when the forced hot water system satisfies, it takes some time for that water to cool, and it is releasing heat into the environment while it cools. When the system calls again, that water is still going to be warm, and require less btu's to get back to the 180 degree working temp. Steam on the other hand won't work as much after the system satisfies, and the steam condenses back to condensate and needs to be heated all over again to change states to a gas all over again. You couple that with any kind of leak in the system, and it is that much harder to pressurize the system.

ChrisJ

Stick said:

The difference in fuel consumption to produce steam, versus hot water is astronomical! To heat one pound of 60 degree water to 180 degree water is 120 btu's, and that's a nominal temp for baseboard heat. To heat one pound of 212 degree water to produce 212 degree steam, changing states from liquid to a gas, requires 941 btu's!!! That's not even counting the btu's to get the same 60 degree water to 212 degrees in the first place! The other component to this is when the forced hot water system satisfies, it takes some time for that water to cool, and it is releasing heat into the environment while it cools. When the system calls again, that water is still going to be warm, and require less btu's to get back to the 180 degree working temp. Steam on the other hand won't work as much after the system satisfies, and the steam condenses back to condensate and needs to be heated all over again to change states to a gas all over again. You couple that with any kind of leak in the system, and it is that much harder to pressurize the system.

You get all of that heat back when the steam condenses,100% of it. it's not waste.

You can also run steam at lower temperatures, pick a number, any number, and it's possible with a vacuum.

Your argument about water taking time to cool and releasing heat into the environment if anything, is a negative. That added mass in a hot water system is a drawback.

If someone would design a modern steam vacuum system it could heat a house better, and faster with a lot less mass than hot water in my opinion. @gerry gill @Steamhead You guys got the details worked out yet? Light weight steam generator, and light weight fin radiators all piped in pex?

This is an incredibly old post by me and luckily, I've learned a lot since then.

Gordy

I'm sure a vacuum system is Much cheaper than a hot water system.

@Stick use this link then see what you think.

http://www.jbind.com/pdf/Cross-Reference-of-Boiling-Temps.pdf

Remember the limits of temperatures with pex, and the added hardware to do a vacuum system. Your taking a simple steam system which everyone brags about as its plus. Then adding a bunch of powered equipment depending on size of system to produce a vacuum.

hot_rod

With hydronics you can heat, cool, and dehumidify. In this modern age cooling is pretty much a must have even in the cool climates and mountain communities.
It seems the goal nowadays is the lowest possible fluid temperatures which allows solar and GEO to be a part of the system.

Still many applications for steam in commercial and industrial applications. And aircraft carriers. China just unveiled a carrier without steam catapults, just a ski jump at the end

I do miss my steam shower unit.

ChrisJ

hot rod said:

With hydronics you can heat, cool, and dehumidify. In this modern age cooling is pretty much a must have even in the cool climates and mountain communities.
It seems the goal nowadays is the lowest possible fluid temperatures which allows solar and GEO to be a part of the system.

Still many applications for steam in commercial and industrial applications. And aircraft carriers. China just unveiled a carrier without steam catapults, just a ski jump at the end

I do miss my steam shower unit.

You can cool with steam too!
Pull the system into a vacuum where water boils at around 50-60 degrees and you're there!

Gordy

Now why would I want to take the extra energy to boil water so I can pull it into a vacuum so I can use it to cool.......Thats why everyone's doing it on a residential scale right? Commercial right?
Of course there is industrial, and commercial variants of this, but why for residential.


See you don't have to pull a vacuum with water

Again people are trying to take the simplicity out of steam, and compare it to water based heating, and cooling. Then saying I can do that.

Show me the cost to accomplish such, and I will listen to the argument. Just because it can be done does not make it economical.

ChrisJ

Gordy said:

Now why would I want to take the extra energy to boil water so I can pull it into a vacuum so I can use it to cool.......Thats why everyone's doing it on a residential scale right? Commercial right?
Of course there is industrial, and commercial variants of this, but why for residential.


See you don't have to pull a vacuum with water

Again people are trying to take the simplicity out of steam, and compare it to water based heating, and cooling. Then saying I can do that.

Show me the cost to accomplish such, and I will listen to the argument. Just because it can be done does not make it economical.

Sigh.

Until you buy a house and have something to experiment with you no longer have a say.

JUGHNE

IMO what killed both steam and hot water is the absolute necessity of having central AC. (Chris, would you go back to your window AC's?)

In my area of the Midwest, central AC is now considered as essential as running water. New house time the GC can profit from the bling of countertops and flooring etc. Hard to sell the customer on the fact that you have hot water/steam plus the cost of AC ductwork.

But steam may have lost out to HW because IMO:
Head room in the basement which must now be part of the living space. (The ductwork might only take up a 10" x 48" soffit down the center of the basement.) Once in the past the basement was dedicated to a heating system, laundry and also the man room.

Individual room zoning.
Heated floors.
No large CI rads that are hard to "decorate" around.
Copper or PEX drilled thru floor joists for flat ceiling.
No chimney up thru the house or roof. PVC inside walls or out thru basement walls.
You do not have to fire the steamer in the summer time for DHW.

Sorry to be so negative.......but if I meet someone who has kept their steam heat they are held in high regard in my book. I would give them free advice on the system and even bring cookies.
Even work cheap to improve the system. ( I have done this just for the cause)

bob_46

I think Chris@ blew it , he missed the chance to have a steam fired lithium bromide and water absorber. Lithium bromide is the absorbent and water is the refrigerant. There are hundreds of absorbers in the Chicago area.

hot_rod

ChrisJ said:

hot rod said:

With hydronics you can heat, cool, and dehumidify. In this modern age cooling is pretty much a must have even in the cool climates and mountain communities.
It seems the goal nowadays is the lowest possible fluid temperatures which allows solar and GEO to be a part of the system.

Still many applications for steam in commercial and industrial applications. And aircraft carriers. China just unveiled a carrier without steam catapults, just a ski jump at the end

I do miss my steam shower unit.

You can cool with steam too!
Pull the system into a vacuum where water boils at around 50-60 degrees and you're there!


And I can cool with hot water, plenty of AC units in China powered by vac tube solar thermal collectors. About 160F will do it.

Why drive the fluid through another phase change (steam) with fossil fuel, let the sun do some of the work.

http://www.yazakienergy.com/waterfired.htm

Steinway and Sons factory in NY heats, cools, and dehumidifies with solar powered energys, NG backup. PM magazine article Feb 09. Lets send Dan or Erin over to see how it is performing.

FranklinD

It's an interesting subject to me too. The area I live in, the western tip of Lake Superior, has very few residential steam systems. Sure, there are several steam plants for the universities, for downtown Duluth (but the company that just bought it is going to switch all the downtown buildings and the distribution system to hot water - they have "green" in their name), and so on. But no residential steam.

Take my block, for instance...the eastern side of the block, 6 houses, were all built between 1914 and 1916. They all have hot water heat, originally gravity. The two houses on the western side of the block were built in the early 50's and have originally installed forced air heat. That seems to be the norm around here, of the house had it originally, it still has it.

But as I said, no residential steam. I've checked every house in town that I've been able to (within reason), talked to a couple service guys I know, and no one has ever come across one.

Why is that? Why would it be prevalent elsewhere in the country, further east, but not around here? Could it be related to hot water being, as Dan said in his article, a Canadian import, and our proximity to the border?

Gordy

ChrisJ said:

Gordy said:

Now why would I want to take the extra energy to boil water so I can pull it into a vacuum so I can use it to cool.......Thats why everyone's doing it on a residential scale right? Commercial right?
Of course there is industrial, and commercial variants of this, but why for residential.


See you don't have to pull a vacuum with water

Again people are trying to take the simplicity out of steam, and compare it to water based heating, and cooling. Then saying I can do that.

Show me the cost to accomplish such, and I will listen to the argument. Just because it can be done does not make it economical.

Sigh.

Until you buy a house and have something to experiment with you no longer have a say.

What's holding you back Chris it seems you went conventional AC.
You already have the ability to make steam.

ChrisJ

Gordy said:

ChrisJ said:

Gordy said:

Now why would I want to take the extra energy to boil water so I can pull it into a vacuum so I can use it to cool.......Thats why everyone's doing it on a residential scale right? Commercial right?
Of course there is industrial, and commercial variants of this, but why for residential.


See you don't have to pull a vacuum with water

Again people are trying to take the simplicity out of steam, and compare it to water based heating, and cooling. Then saying I can do that.

Show me the cost to accomplish such, and I will listen to the argument. Just because it can be done does not make it economical.

Sigh.

Until you buy a house and have something to experiment with you no longer have a say.

What's holding you back Chris it seems you went conventional AC.
You already have the ability to make steam.

Money
Time
Your negative attitude

Gordy

Hot water heat had the hurdles which steam had. Think gravity hot water heat. A simple circulator decreased pipe size, and changed how piping could be routed due to the fact that gravity no longer had to intentionally drive the system.

ChrisJ

> @Gordy said:
> Hot water heat had the hurdles which steam had. Think gravity hot water heat. A simple circulator decreased pipe size, and changed how piping could be routed due to the fact that gravity no longer had to intentionally drive the system.

heat pipes work fine

Gordy

ChrisJ said:

Gordy said:

ChrisJ said:

Gordy said:

Now why would I want to take the extra energy to boil water so I can pull it into a vacuum so I can use it to cool.......Thats why everyone's doing it on a residential scale right? Commercial right?
Of course there is industrial, and commercial variants of this, but why for residential.


See you don't have to pull a vacuum with water

Again people are trying to take the simplicity out of steam, and compare it to water based heating, and cooling. Then saying I can do that.

Show me the cost to accomplish such, and I will listen to the argument. Just because it can be done does not make it economical.

Sigh.

Until you buy a house and have something to experiment with you no longer have a say.

What's holding you back Chris it seems you went conventional AC.
You already have the ability to make steam.

Money
Time
Your negative attitude

I really don't know where that came from, but I'll respond accordingly.

As for the first two, and other reasons posted in the discussion I guess that closes the case on this topic.

As for the third. I would call my attitude realistic. Oh and quite positive. However if you perceive it as negative, and it affects your life decisions I think you need to work on that.

Now back on topic, and enough of the ad hominem attacks.

"Why hot water, and not steam" was your discussion. Upon writing that title, and your opening post obviously you understand that hot water has the market share over steam. You also ended by saying you want to expand your knowledge. I think there has been plenty of information posted to draw a conclusion. If you chose to do so Chris.

I will also say I have no problem with steam heat. In its oldest form of elegance, and simplicity.

What I do have a problem with is when people take all that simplicity away in an effort to mimic the benefits of hot water by adding vacuum to take advantage of smaller piping, and maybe using it as an advantage to right a poor initial design then deem it as superior to hot water.

In doing so you have basically added pumps in the same way that changed the way gravity hot water heating improved the way hot water heating was done from that point on, and forever.

Personally I want to see the math behind the economics of both converting an existing steam system to vacuum, and a vacuum one from scratch. if anyone is willing to share.

Bottom line both still have boilers, or "furnaces" if you prefer that term. I don't. Both have distribution piping, and both have a heat emitter to the room. Water based systems have more choices in types of emitters. Hot water has modulating boilers. Steam can have two stage gas burners in their boilers. Hot water as been stated can take advantage of many types of heat sources solar, gshp,air to water heat pumps.

Robert O'Brien

The choice isn't between steam or hot water, it's between air or hydronic. And that isn't even close.

ChrisJ

@Gordy





However, one huge difference between you, and @hot rod is I believe hot rod does a ton of experimenting with this stuff, rather than just following ideas of others. This means he has a say. you don't.

How could you think I was serious about your attitude, and why would it have any effect on what I do? Lighten up!