U.S. DOE Misinformation regarding Steam

Dean_7

I'm going to throw my two cents in here. My one pipe system was originally installed in the late 1920's. Coal fired boiler and all. By 2003 when I restored the system the boiler had been converted from coal to oil to gas and was on it's last legs. All the main vents were missing and three radiator vents were failing. The thing is everything was the same age 70 + years and it was still working granted not well but still working. Restoring the system cost about a third of what replacing it with forced hot air or converting to hotwater would have (and both were considered). And I like my radiators. With the new boiler, the main vents replaced, new radiator vents, and a vaporstat our fuel costs over the last full year were almost 60% less then before the restoration. How much more efficient can you get?

t. tekushan

U.S. DOE Misinformation regarding Steam

Well, now that summer is over, my thoughts have returned to steam heat (really. I can't think about steam when the temps are over 85 and night time humidity is 85).

Anyway, I stumbled across something on the Department of Energy's efficiency web site. It got my blood boiling! Here's the page:

http://www.eere.energy.gov/consumer/your_home/space_heating_cooling/index.cfm/mytopic=12580

What they are saying here is that steam heating is inherently inefficient compared to "modern" systems. Based on my experience and thermodynamic theory, this is pure B.S. that just seems to parrot preconceived HVAC industry notions presented without any evidence to support that claim whatsoever.

Of course, we've all seen steam systems using fuel at an alarming rate. For crying out loud, is it so hard to believe that an 80 year old steam heating system might need a tune-up? Are they suggesting that modern systems won't? They won't because they won't exist in 80 years. But I digress. Usually the basics like vent and/or trap replacement, checking pipe insulation and pitch, descaling the boiler (or replacement if woefully inefficient) and burner cleaning and adjustment will reduce fuel consumption about 40 percent right off the bat.
Then you can add all the fancy stuff that ensures minimum run time, outdoor temp sensors, etc.
I talked to a guy with a smooth running steam heating system who was complaining about his heating bill suggesting that steam heat is his problem. OK. I pointed out that he was dealing with 4500 square feet of space kept at 70 degrees without a shred of insulation anywhere in the house (you could see the snow melt on the roof) and leaking windows. Do ya suppose something other than the steam system is responsible for these high costs? Hmmmm? But this is typical. And so are neglected steam systems, or worse, systems that have been subject to some invasive procedures of dubious merit (putting it nicely).
Yet, year after year people are told its "steam's inherent inefficiency." Horsepucky.

Furthermore, the DOE article states that since steam heat takes sooooo long to heat, that it is not suitable for temperature set-back! AAAAAAAGH! This is so totally opposite the theory and my repeated experiences (steam likes that longer run time, and oooh does it get cookin').

The long and short of it is that I must respond to the inaccuracies in the DOE web site. Are there any suggestions out there as to citing specific studies of steam heat as a system vis a vis other heating types? I need to load up on info to "learn their a**'s."

Thanks.

-Terry

J.C.A._3

Steamhead.....

Has a study in progress. The results he's posted so far are pretty impressive. I don't have the post bookmarked, but I'm sure someone here does and can direct you to the findings he's had. Chris

Dirk Wright

Did you contact the DOE about this?

Steamhead (in transit)

Links

here's the one to the ongoing study JCA mentioned:

http://forums.invision.net/Thread.cfm?CFApp=2&Thread_ID=22035&mc=22

Here's one that was even more impressive- thanks, Dean!

http://forums.invision.net/Thread.cfm?CFApp=2&&Message_ID=171303&_#Message171303

and a similar one on a Vapor system- thanks Bill:

http://forums.invision.net/Thread.cfm?CFApp=2&Thread_ID=21386&mc=33

Here's a comparison of steam vs. scorched air in similar houses:

http://forums.invision.net/Thread.cfm?CFApp=2&Thread_ID=25079&mc=7

I have zero confidence in the federal government these days. Fortunately many other people share that opinion so that web site might not have its intended effect.

Sure we could contact DOE, but I'll bet they put that there intentionally to encourage people to rip out steam systems and put in scorched air. Remember the scorched-air people came up with AFUE which is weighted against hydronics and steam, so you know who has been in bed with DOE all this time. That plus the fact that we don't work for Halliburton means they probably wouldn't listen to us.

t. tekushan

I have not yet contacted the DOE

on this subject. I just came across this. So I merely wanted to jog everyone's memory on documented cases so I can respond to them with something more than anecdotal evidence. I have kept track of Steamhead's impressive results, which mirror my own limited (and undocumented) results.

How does the AFUE rating favor forced air? I don't doubt it at all. I'm in the audio component design biz and have had to fight this sort of thing for years. Industry standard measurement techniques are not flawless and and the standard measures of performance always favor the technology most widely used by those who set the standards. The result is the same. We wind up with a very good idea of how a component (furnace, boiler or audio amplifier) performs by itself OUTSIDE ITS APPLICATION and the system environment (including the home or building) in which its to be used.

If any more helpful info comes to mind, post it here. I'll put it together in the form of a response to the DOE.

-Terry

ed wallace

DOE results

now thats a joke DOE results are done under controlled conditions I wonder how many rads they hooked up to a steam boiler to test steam systems, to bad DOE will not look at steamheads data

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

t. tekushan

thanks for links

I'm studying these. Thanks for the info. Now to put the ol' literacy to work and send them a professional but flaming response. [should the response have an AFUE rating?]

BTW, I've been threatening to install steam heat in our forced air house. I already have the boilers of the appropriate size to run the two zones, and about half the radiators I need. The first floor is easy to deal with. The second makes my brain hurt. I really don't want to tear apart so much absolutely perfect plaster (house was built in '39). I'm thinking overhead for the second floor thru the attic as it seems that running small returns thru existing walls would be less damaging a process. For a brief moment I considered plumbing the whole darn thing with a garden hose!
But with natural gas prices to go up at least 30% more around here, I need to do something. And snuggling up with an Alpaca is out of the question.

thp_8

What they don't understand must be bad.

Nothing gets me more worked up than a steam system that gets the axe and a hot water system gets put in to save money. They are the biggest scams going. What I really like is that the old system was neglected for the past 20 years and still worked. The new system after a design and build ( or as I see them the D&D design then destroy ) are usually junk in 10 years or less. The other question I usually ask is why do we use steam to generate most of are power if hot water is so good?

Steamhead (in transit)

I had a run-in with Beckett about that

they inserted that concept in their "Professional Serviceman's Guide to Oil Heat" page 55 for those of you who have a copy, and when I saw it I called them up and told them what I thought of it. We'll see what they do in the next version.

Steam power applications are very different from steam heating, although in some cases they coexisted in the same plants. In a power application you're building a lot of pressure to do work. In the usual heating system you only need a few ounces of pressure to overcome the resistance in the piping.

So when are you installing your steam system?

thp_8

Simplicity

What I was going after in that last rant is the thing that keeps alot of those old systems going is the simplicity of design. Less moving parts and so on. Alot of the systems use good old gravity and steams own self-expansion to move itself. The other point I like to bring up from time to time is that if you want to move 1,000,000 btu's normal figured with hot water you will move roughly 50,000lbs of water. The same in low pressure steam you handle 1,000lbs of condensate. If it's a all gravity system it moves its self. You don't need a big floor base pump to do that. But maybe thats to simple for some people. Which one?

Mike T., Swampeast MO

Furnaces are very different animals than boilers.

A furnace is akin to a boom box. Rating is made by measuring the decibel level of the built-in speakers while driving a sine wave at clipping.

A boiler is more akin to a power amplifier. Rating is made by measuring the electric output while driving a sine wave through a fixed resistor.

The problem is that the furnace is NOT used like a boom box in practice. The internal speakers are disabled and it's connected to a number of series-connected speakers in various places.

If the remote speakers are at all tested in the process you can assure they were connected with continuous monster cable, soldered connections and perfectly selected high quality speakers that ensure the same db level regardless of the size of the space.

In reality, they are typically connected with frequently spliced phone wire, loose connections, and little concern of speaker selection to the space. To make matters worse, the insulation of both the wires and the voice coils is poor and the cone surround lacks compliance. There's lots of leakage current that does not become sound and the signal is quite distorted.

The one good thing about the "speakers" in this system is that their impedence is almost perfectly consistent with changing frequency and the efficiency of the amplifier remains consistent.

The boiler on the other hand is always used like a power amplifier. In reality its speakers are almost always connected with monster cable and soldered connections. The speakers may not be particularly well-selected, but you can almost guarantee that the signal has been little altered on its way. The speakers in this system however have highly varying impendence and the amplifier works with varying efficiency at different frequencies.

In these conditions, direct comparison between the two types of systems is very difficult with just a single number used for rating. Some say that the methods are designed to show a higher performance rating for the boom box--even before it's connected to external speakers. I'm not sure, but I do know that the boom boxes are much more common... Some say that the methods used to size the boom box's amplifier to the space (heat loss) is intentionally skewed to account for the crappy wiring in the boom box system. While the actual intention is in doubt, the fact that the sizing is overstated is almost universally accepted. When something like Klipschorns are used in the power amplifier system, it is nearly as universally accepted that the amp can be significantly smaller than the calculations suggest.

Neither of these systems however actually produce music. They produce noise. The noise from the boom box is loud and quite distored whenever it plays. The noise from the power amplifier does however vary in volume and with certain controls can sometimes sound a bit like music.

A condensing/modulating boiler however is like an integrated amplifier. It DOES produce music because it is fed via a built-in tuner. Unfortunately however, the performance of this tuner through the speakers is not currently rated. This makes comparison between this and other types impossible given a single number.

Jamie Hall

and my penny

my vapour steam system is almost a century old now, with a new boiler, two new main vents, and a new cold return line (the old one rusted out...). Try that with scorched air or hydronic...

Oh yeah, it's not bad on the efficiency either, and there is no reason it shouldn't be!

Christian Egli

Amplified steam

I like the tune I'm hearing

This is a new one MikeT, but I think I am getting your analogy loud and clear. It's catchy, I'll hum it a few more times until it sinks in.

I guess the grand finale for your analogy is how we should all find that boom boxes are a nuisance. Don't city councils pass ordinances against them?

For now, it's still way to hot here to turn the boiler on. I'm enjoying the comfort from the vapor cycle that makes my AC go round. Evaporator = boiler. Condenser = radiator. AC, heat pump = fantastically modern. Steam heat = ????

t. tekushan

I like the analogy

since it brings forth the actual complexities of each system that a "dumbed down" and simplistic measured standard can not express.

Which brings me to a somewhat related point. If I'm going to assemble the pieces that I have (including a low hours burnam CI boiler), and I want to operate the system at vaporstat-appropriate pressures, is there any way to get this boiler to "modulate" at least within a fairly narrow range? I'd hate to have to build something myself if there are already commercially available retrofit modulating valves.

The commercial steam systems that I am familiar with are in particular:
-Kewanee 100 HP firetube modulating boiler with vacuum return-- awesome to observe operating! It would fire at 20% and build based on demand. Best efficiency was 80% or less of full capacity.
-Sellers firetube forced induction boiler array. One of the best boilers I've seen. Their design and construction is amazing, and quite efficient. They can't be modulated, but will fire sequentially on demand. Being steel, it seems that the downtime losses would be lower than cast iron.

Naturally, what I REALLY want is a mini steel fire tube designed like the sellers, and operate two in tandem. Oh well.

Oh. Since I'm contemplating the impossible... I should point out that the radiation that I have acquired and have earmarked for use in specific rooms is not oversized, and actually a touch under what the house currently needs. Insulation is to be added. Its ongoing. Why can't the vaporstat hand off to [or be disabled in favor of] a standard pressuretrol when the run time of the boiler exceeds a specified period, e.g. if its below zero outside?
Its simple to do-- series connect the two controls- the pressuretrol would usually run as a redundant safety, fully hardwired. The vaporstat has shut-off "veto power" over the pressuretrol. A simple bypass relay will keep the vaporstat portion ofthe circuit closed when necessary. A run-time processor or simpler yet- an outdoor thermostat would control the relay.

I've watched a commercial system build pressure to 10 lbs (I'm not suggesting anything this radical, but just humor me) and of course the output of the radiators went well beyond their 1 lb ratings! What a sight to behold. Ahhhh the power of steam. Believe me, it could have been -50 degrees outside and it could handle it!

I propose a modest version of this where a couple of pounds of pressure can be developed under extreme conditions. This is why a little modualtion would be nice.

Of course I am sizing the piping for verrrrry low pressure, and will be very careful about pipe pitch, venting, and returns. I don't need things to go "bump" in the night if it kicks into high gear!

Any thoughts on this one, or do you think that simply the "modern" sizing techniques and good venting will get me adequate performance?
but I sure do like the idea of being able to get that "pedal to the metal" performance that is so uniquely "steam."

-terry

Steamhead (in transit)

If you size and install it right

and run it at Vaporstat levels, the pedal will go to the metal without you even pushing it hard.

thfurnitureguy_4

Hope to join the party

I never thought I would look forward to a heating season but I'm like a kid with a new hot rod. I took the sag out of my main pipe, I just finished the re-positioning of my returns. My drips are now wet again. It wasn't fun crawling down the spider hole attaching all of the drips but I think that the way it is done now will last a long time. The nice thing is that the system has flush valves at each end (for the first time) and I don't have to go back down the hole to flush it out! I'm sure there are things I don't know about yet but I can't wait to flip the switch. We have all of the data from last year on oil consumption. It should be a good comp. Thanks to Steamhead and the wall for all the help last year and this year to come. T.

Mike T., Swampeast MO

Bias Current = Flue Loss

Steam Boiler = Class AB amplifier with quite high bias current.

Furnace = Class AB amplifier with bias current determined by AFUE.

Hot Water Boiler = Class AB amplifier with bias current determined [mainly] by present load.

Condensing/Modulating Boiler = Class AB amplifier with bias current determined by present conditions of demand, supply temp and return temp. When modulating to meet demand, bias current drops to the point that it appears to be more similar to a Class B than a Class AB.

Christian Egli

Beating the clock with the HeatTimer

I think the scheme you describe is what a HeatTimer control system does. It operates on outdoor temperature which determines the run time and the run time is measured starting when the end of mains get hot. Like CNN and repeats on the hour, the quarter hour, or whatever you set it at.

It does not get obsessed with pressure though. That's just determined by your system and your pipes.

Timing the system stops the building of unnecessary pressure. If we suppose the pressure setting would be set way high, your system would be allowed to build pressure for the hypothetic conditions.

I don't really see a need for high pressure particularly on a critically cold day. On that day, because of a large step in temperature between the radiator and the cold indoor air, your radiators will be condensing all the steam the boiler can produce. Thus not leaving any uncondensed vapor to build more pressure.

Unless of course, you installed a humongously oversized boiler. In that case, you'd have all the fire power to build whatever pressure you wanted. But this is not what home steam heating is all about.

The pressure moves the steam, the lesser, the faster it all moves. And the steam dumps the heat when it condenses.

As far as modulating pressure, I see more value in modulating down into vacuum and dealing with lovely vacuum generators.

Nice post.

subcooler

If you add

a little vacuum to the system, even at a idle you can still be pulling a big load.

Steamhead (in transit)

One word, Tom-

Pictures!