Steam vs Hot Water In New Construction

P1385

Good morning all,
It seems that this question brings up many people's hackles, but I'm genuinely not trying to knock one tech vs the other. I've searched the wall and cannot find (probably my oversight) where an apples-to-apples cost-to-operate of the two systems was discussed in a new construction. They often seem to be in the vein of, "I installed a hot water baseboard system in this 50-year-old house and the homeowner's bill was cut in half!" or, "I corrected the piping on a new steam boiler install in a 100-year-old house and cut the homeowners bill to 1/3!" and such forth.

I'm going to be building a new house next spring (modular (homeowner-GC)). I'm in lower Michigan and would like to go with a non-forced air heating system. The house will be a ranch of ~1,800 sq. ft. on a full basement.

I grew up with hot water and loved the even heat. On the other hand I'm intrigued with steam and not having to run a circulator constantly through the winter. I have a moderate understanding of steam from my job (industrial PVF sales at an Armstrong distributor) and have access to seasoned steam veterans for guidance. I would be running the black pipe and installing the baseboards myself and leaving the boiler install to a local contractor.

What is the professional consensus of cost-to-operate steam vs hot water for this application? Thanks in advance!

Jamie Hall

Not a professional. So I don't know if my opinion would count. However...

It is very much more a question of the overall efficiency of the system -- including the boiler, any pumps, and the radiation -- combined with the cost of money (which, right now, is really cheap). On that basis, I would go with a really well designed and installed hot water system, using a high efficiency, modulating, condensing boiler with outdoor reset. But that assumes that you have gas. Also, if you want baseboards rather than radiators, that tilts it very much towards the hot water system.

And all that said -- I'm a steam guy!

Leon82

If you were going to do steam I wouldn't do it unless you got full size radiators.

Otherwise design it for low temperature hot water with panel RADS or the high output baseboard. Or even have a radiant Zone as well

P1385

Jamie Hall said:

...if you want baseboards rather than radiators, that tilts it very much towards the hot water system.

Would this include the Burnham Baseray CI steam baseboards? I'm not familiar with them, but they seem to be what is used if a traditional radiator isn't wanted.

leonz

Another option would be gravity hot water with the expansion tank in the attic using a drain line to the basement laundry sink or floor drain.

A steam boiler the size of a typewriter cart will create a huge amount of heat for you and you can use copper piping if desired rather than schedule 40 steel pipe provided it is allowed by the local code.


If I can promote a couple of Dans books you should buy and read-

"Pumping Away"
"Greening Steam"
"How Come"
"Classic Hydronics"

These four paper backs and the other books he has written about plumbing and heating are a wealth of information for both the layperson (you and me) and the professional plumber as well. zdan ,makes his writing fun to read with lots of true stories and information about the history of heating and the "dead men" who are responsible for the proper design and use of steam, gravity hot water, hydronic heating and forced air heat.

The great thing about one pipe steam and gravity hot water is that the boiler can be or is centrally located and you can simply locate the radiators where you want them and then plumb them in.
Steam radiators can be placed on the interior walls to simplify the single pipe plumbing runs to each radiator.

The gravity hot water system requires two lines one delivering the hot water by simple gravity from the open expansion tank in the attic and then the second line from each radiator letting the cooler water fall back to the boiler header sump line by simple gravity.

The gravity hot water system would allow you to place the radiators on the inside walls away from the exterior walls and windows and make the plumbing runs simpler with copper or pex piping as they would be closer to the center of the home.

You could employ a single circulator to feed additional hot water to the open to air expansion tank in the attic to increase the speed of hot water delivery by gravity to the home with simple plumbing as the gravity fed lines to each radiator would be taking the hot water and letting heat the specific area and then drop back down to the boiler to be reheated.

Gravity hot water heat is a slow even heat that works well with out pumps and many old homes use it.

One pipe steam also works well and is easier to take care of as long as the steam system is maintained properly with simple maintenance and boiler treatment.

After seeing how badly the in floor hot water heating system was installed under the hardwood floors by the package home building company in my new fathers home and how they did not install reflector panels or insulation to hold the heat in my brother had to install aluminum foil backed insulation board to the ceiling joists to correct the builders screw up. I would never use this type of heat as I saw the damage the heat did to his hardwood floors.

JUGHNE

leonz;
So what is the efficiency of a modern boiler that can supply gravity flow, without a pump.
In a modern house the attic temp should be outside ambient, what keeps the tank from freezing?
The preferred best place for heat emitters have always been on the exterior walls where the heat loss is the highest.

I can't imagine a gravity system in a modern single story house.
They were great in their day and some still are functioning well in century old buildings.

And if the steam route, then a 2 pipe vapor system would be the first choice.

Fred

Take a look at this mini-tube steam system that @gerry gill designed and installed. This is likely a very viable option for you and Gerry may be able to give you some operating/installtion cost comparisons.
https://forum.heatinghelp.com/discussion/151994/new-steam-mini-tube-installation-in-ohio/p1

Pumpguy

I wouldn't be afraid of installing the boiler yourself. Back in the day, my dad installed, along with a bit of help from me as a young teenager, his whole hot water heating system. And he was not a tradesman by any means. Just follow the instructions and you'll be fine.

Two story cape cod home with expansion tank in the basement, just above the boiler.

Many years later, the circulating pump sized and it was months before we realized it. Hot water gravity circulated with little noticeable change in overall comfort.

jumper

I love steam but somebody has to look in on the boiler every now and then. For both steam and how water I'd install those modern steel panels close to the ceiling,on interior walls. More radiant versus convection. Steam is lighter than water and its higher temperature improves radiant.

In either case I'd manifold in the boiler room and run individual tubes to each panel. If you really want to go Cadillac you can manifold in attic. For HHW gravity the trick is a closed evacuated expansion tank in attic. You'll have to think carefully how you fill system to correct level. The beauty of gravity with closed expansion is that it should never need additional water.

Now for your question about if HHW really burns less gas than steam? I guess not because steam's higher temperature occupants will adjust TRV s lower. My guess is based on reported experiences with electric baseboards versus ceiling level electric heaters.

EBEBRATT-Ed

If I ever had the chance I would love to install a steam system in my house when I relocate. But that's because I love steam and could do the work and the maintenance myself.

Hot water is tough to beat and being practical it's the way to go, especially if you have gas. The simple fact of modulating firing rate is a big plus

leonz

JUGHNE said:

leonz;
So what is the efficiency of a modern boiler that can supply gravity flow, without a pump.
In a modern house the attic temp should be outside ambient, what keeps the tank from freezing?
The preferred best place for heat emitters have always been on the exterior walls where the heat loss is the highest.

I can't imagine a gravity system in a modern single story house.
They were great in their day and some still are functioning well in century old buildings.

And if the steam route, then a 2 pipe vapor system would be the first choice.

---------------------------------------------------------------------------------------------

Edited today-Wednesday to fix my clerical mistakes :^(

If I remember Dan and what others have told me correctly you can install larger diameter pipe and use a reducing bell fitting and a short nipple with a ball valve on the newer boilers steam chest tapping and install a larger diameter pipe joint on the reducing bell fitting and move large amounts of hot water that way and do the same for the gravity return using the modern boilers available today.


Regarding the use of open to atmosphere steel expansion tanks in cold attics:

The way Dan explained in his book Classic Hydronics as to how they kept the steel open to air expansion tank from freezing was this way;

They placed a close nipple in the bottom of the steel expansion tank and then put a tee on that nipple and then put a close nipple on both sides of that tee and then they installed two elbows on those nipples so that the hot water would heat the water in the steel expansion tank and return to the basement at the same time keeping it from freezing and keeping the hot water moving at all times simply by falling back down more quickly to the basement to the boilers sump.

Speaking as a layperson I would not hesitate to install a gravity hot water system in a modern home with steel pipe as they can install the radiation on the interior walls with any needed access to the pipe runs.

New England SteamWorks

The only problem with steam is the initial installation cost. Once it's in you'll be virtually maintenance free, but it's a long payback. So, lots of upfront cost and difficulty finding someone to do it right, vs baseboard which anyone can do.

MilanD

Wow. What a great question! To me, anything too complicated or too finicky, or too complex that needs special knowledge and one tech knowing it vs. every tech knowing it is a no-no. Same on equipment being complex or needing complicated and complex servicing. Call me old-fashioned. I suppose it's long-term operating costs that will include not only fuel costs but also cost of servicing is what I would worry about. Shelling out a couple of Benjamins every time something is off would not be an issue if techs were guys on this forum. Most are not and as we can see on the forum, many homeowners have problems with techs who have no idea what they are doing.

As you can also see from posts here, not a whole lot of techs country-wide know steam. If you are lucky to be close to someone who does, great. At the same time, steam is quite simple system once you understand it, and once it's set up properly it can last for ever. One pipe or two pipe. Key is proper setup. Maintenance is also not too complicated, especially so on gas fired boilers, and the only other serviceable parts are the vents: on the radiators and the main if 1-pipe, or just on the main if 2 pipe with an orifice and no individual rad traps. On 2 pipe you can easily also have your system do vacuum, and that will further make the house heat feel as comfortable as you want. @IgorZhadanovsky (or @izhadano) does one pipe vacuum systems too. So, there is a lot on steam side that is great. If you decide steam, several guys here can consult and plan out a system that will be awesome.

Hot water side, with modulating condensing boilers and home run pexalpex piping you can pretty much match heating to the heat loss and make each rad a separate zone and install it quickly. This makes the system as efficient as you can have. Problem with this is, in my humble opinion, that not many people know how to properly choose the right boiler for the application and to install them properly with a proper system. 2nd problem is that servicing mod con boilers, which requires knowledgeable techs, adds to overall operating costs. But, system can be very very comfortable. Just like steam. You can also do simpler systems with hot water, and throw an outdoor reset controller and be done.

So, perhaps it would be good to talk to a heating consultant, someone who is up on the latest technology. Perhaps hire one of the guys here who does both as a consultant.

It's a tough one. For me it's steam with the natural gas boiler. I know it, understand it, enjoy it, and although not a professional in this field, I can pretty much do everything on it my self, including piping and repiping. That being said, if $$ were no object and if starting from scratch, I'd probably do a mod con and pexalpex homerun rads with tstat in each room on a nice cast iron radiator for good thermal mass and radiation.

Great thought exercise, for sure. Good luck and keep us posted on what you end up doing.

Dave0176

Funny you asked this, my wife and I are now looking for a new home, and she asked what do you want, I say anything with a basement. Next she asks wisely what type of heat because I know you want steam, even though 100 year old houses give my wife the creeps, I told her what ever it don't matter. Because if it isn't steam there will be a brand new system installed by me. And Im not particular, one pipe steam will suit me fine.

JohnNY

Forced circulation hot water allows a great deal more flexibility in layout and design. Hot water uses smaller pipes than a steam or gravity system and the forced circulation takes the need for pitching pipes out of the equation. Forced circulation allows for many more options in selecting terminal units and zoning devices.
Steam is wonderful and I work with it all day long in New York City and the surrounding areas but there are very few compelling or valid (to me) reasons to install a new system in a home in 2017.
Yes, that is sacrilige of the highest order to some but I feel hydronics is ultimately the most practical of the options.

AMservices

With steam The big steel pipe is expensive, but then the radiators or base board can be smaller.
Forced hot water the piping is smaller, but then you need twice the amount of radiation.
With steam you never have to worry about a frozen pipe bursting.
The more zones the better balance.
With hot water that takes a lot of thermostats, controls, pumps, zone valve, ect.
With steam every radiator can be use as a zone by using TRV's and 1 well placed t-stat.
With the modcon boiler you need to have it serviced every other year, have a qualified technician that knows how to use a combustion analyzer comes out and make sure It's still running right, Replace gaskets and charge you every bit of the 15% you saved with a high efficient burner.
With steam if it's piped right, the boiler is sized right, all you have to do is keep the water clean and make sure your air vents or steam traps are working.
Depending on how fancy you get with a hot water system, I would think the overall installation cost Could easily be the same. But then the long term operating cost of the hot water system will be more expensive. I Would also expect that the hot water Boiler would need to be replaced Before a steam boiler would need to.

If it were my house I would definitely put in a 2 pipe steam system. Then to decrease the pick up losses I would install a vacuum pump on the return to mechanically remove the air, lowering the Atmosphere pressure and the boiling point of the water, rapidly filling the system.
Having a vacuum pump would allow me to use smaller pipe And rather than steam traps I would use Orifice plates With slightly oversized radiators.
Another benefit of a vacuum system is that it is Self balancing. At the end of the heating cycle the burner shuts off And the steam starts to condense back into water. As it condenses it creates a own naturally induced vacuum That will continue to lower the boiling point of the water and because the cast iron boiler block Is still hot long after the burner shuts off, Steam will continue to rise into the system, Favoring the radiators that are condensing the steam faster Creating a stronger vacuum, those radiators will be found in the colder rooms in the house.
But don't let me lead you to believe that you need a vacuum pump to have a steam system operate like that. instead of a main air vent on a 2 pipe system all you would need is a solenoid valve That opens to let the air out and closes At the end of the heating cycle keeping the air from getting back in.
The long term pay back with steam Comes with reliable, comfortable, efficient operation.

P1385

AMservices said:

If it were my house I would definitely put in a 2 pipe steam system. Then to decrease the pick up losses I would install a vacuum pump on the return to mechanically remove the air, lowering the Atmosphere pressure and the boiling point of the water, rapidly filling the system.

Having a vacuum pump would allow me to use smaller pipe And rather than steam traps I would use Orifice plates With slightly oversized radiators.

Another benefit of a vacuum system is that it is Self balancing. At the end of the heating cycle the burner shuts off And the steam starts to condense back into water. As it condenses it creates a own naturally induced vacuum That will continue to lower the boiling point of the water and because the cast iron boiler block Is still hot long after the burner shuts off, Steam will continue to rise into the system, Favoring the radiators that are condensing the steam faster Creating a stronger vacuum, those radiators will be found in the colder rooms in the house.

But don't let me lead you to believe that you need a vacuum pump to have a steam system operate like that. instead of a main air vent on a 2 pipe system all you would need is a solenoid valve That opens to let the air out and closes At the end of the heating cycle keeping the air from getting back in.

The long term pay back with steam Comes with reliable, comfortable, efficient operation.

I was tracking with you up until this point, then I got lost. What you say is interesting. Can you point me somewhere that I can dig in and get a better understanding of vacuum systems?

Also, do you have any experience with cast iron steam baseboards? I'm leaning toward those instead of full sized rad's if I were to go with steam. Functional? Efficient?

Thanks!

PMJ

JohnNY said:

Forced circulation hot water allows a great deal more flexibility in layout and design. Hot water uses smaller pipes than a steam or gravity system and the forced circulation takes the need for pitching pipes out of the equation. Forced circulation allows for many more options in selecting terminal units and zoning devices.
Steam is wonderful and I work with it all day long in New York City and the surrounding areas but there are very few compelling or valid (to me) reasons to install a new system in a home in 2017.
Yes, that is sacrilige of the highest order to some but I feel hydronics is ultimately the most practical of the options.

Clearly you are right about the control options available with forced HW. Clearly also that system has many more devices to maintain than 2 pipe natural vacuum steam. The potential damage from a freezing event is there too. Would be tough for me to give up the simplicity, ultra low maintenance cost, and and no freeze worry aspect demonstrated by my 90 year old system with any long term thought at all. But who expects to stay anywhere long today anyway and who considers those who come after them even for a moment? I think you are right about what the market would choose.

NY_Rob

Another non-professional here.....

The Burnham BaseRay and Gov-Board (exactly the same product) are wonderful cast iron baseboard rads that can be used in hot water or steam systems.
I replaced 16' of fin-tube with 18'ft of Gov-Board over the summer, we have just started using heat here on LI, and the Gov-Board has worked out even better than expected in the area where they were installed. They take some time to heat up which is great for the mod-con boiler... and they retain heat for a long time which reduced boiler cycling and more importantly keeps the room at a more steady state temperature vs. up and down temps with the no-mass fin-tube.

I literally no nothing about steam, but if you do go with a mod-con hot water system... if you have sufficient wall space to run cast iron baseboard rads at 120F it is super comfortable and efficient.

gschallert

P1385 said:

What is the professional consensus of cost-to-operate steam vs hot water for this application? Thanks in advance!

A properly designed hot water system with modcon & low SWT with ODR will always beat even the best steam install in terms of installation and operation costs. Steam is great but its time in residential settings is in the past. It is still relevant in commercial applications but you will see more and more new building codes set heating efficiency standards that steam boilers just can't meet.

jumper

TRV s take care of balance on new systems,two pipe steam or HHW. Individual pipes to each terminator do not have to be large even with gravity HHW. A new house will be insulated & tight so terminals can be on interior walls. A little condensation or frost on window overnight is no big deal.

For expansion tank at top of system you can have an overflow going back to basement. So you fill system until it overflows. During heating season there will be more overflow until correct amount of water is left. Then you evacuate air and close off the tank. At this point you have an airless hermetic HHW set up. Should not need attention until your boiler craps out.

My guess is that either is less expensive than radiant floors and less troublesome. I hope OP will report back.

The Steam Whisperer

Hmmmm

Steam needs big pipes....no

Minitube steam uses 1 inch copper mains, 3/8 inch heater supplies and 1/4 inch returns

Hot water provides better control....no

Steam can be provided with room by room trv control just like any hot water system. Steam can be set for outdoor reset based on pressure or on steam temperature ( vacuum operation)

Hot water has modulating burners.....

Almost any high efficiency steam boiler power burner design can have modulation

Hot water is more efficient... the Government standards say so

There may be some advantage with hot water boiler in heat transfer efficiency when comparing a noncondensing steam boiler to a condensing hot water boiler. However, comparing a condensing steam boiler to a condensing hot water boiler the difference is only a couple points.
Government efficiency numbers also does not look at electrical use, which with all the pumps , electronics etc, on a "high efficiency boiler" can cause a significant increases in electrical usage. Electricity is only about 30% efficient when it reaches a building and then pumps etc are often only in the 50% efficiency range. Overall energy usage for a modern design steam system and hot water system are probably very similar once you take all energy usage into account.

Steam has the advantage of emitters about 1/3 the size needed for a "high efficiency hot water system", cutting its up front cost even further and is not prone to freezing during power outages or equipment failures. With the very small copper piping and tiny emitters, I would suspect a simple home steam system is less costly than an equivalent hot water system.

For hot water systems, I now avoid modcon boilers due to the fragility and need for higher cost maintenance and repairs and, of course dramatically short life. A simple beefier, modulating cast iron or good copper tube boiler appears to provide about 60 to 70% of the fuel savings attributed to MODcons. Just look at the fuel savings achieved with step fired modular boilers as an example.
Installing either system with trvs in a well built efficient new home will result in such low fuel usage that using a simple cast iron "boat anchor" of a boiler seems to make a whole lot more financial sense than the high cost of "high efficiency" equipment.
Both systems have advantages, but those disadvanges of steam most often given that are listed above simply are not the case with modern systems.

PMJ

@The Steam Whisperer,

I do agree with your points. But the government has decided that instantaneous transfer efficiency in the boiler itself is the number that trumps the total of all others. In so doing they have basically stopped all residential steam development. I will put overall efficiency of my 90 year old system and 60 year old boiler up against anything they are installing today.

Transfer efficiency gets better and better the thinner things get. Whether they last any time at all isn't included in the figures. Makes no sense to me. I'll just enjoy what I have while I can.

Jamie Hall

AT @PMJ -- see my comment on that on the Richardson Boiler thread!

Steamhead

PMJ said:

@The Steam Whisperer,

But the government has decided that instantaneous transfer efficiency in the boiler itself is the number that trumps the total of all others.

Government is the problem here. What do they know?

Look at what's happened in Europe. I read a while back that if you have a five-year-old boiler in some European countries and it breaks down, you may not be able to get parts for it. So if you want heat, you get a new boiler. This is all driven by the push for instantaneous heat transfer. The boilers just don't last.

Where is the savings if you have to replace the boiler every five to ten years?

@The Steam Whisperer (Formerly Boilerpro) has it right.

AMservices

@P1385
Mechanically induced vacuum systems and naturally induced vacuum systems Have been around for over 100 years. @Dan Holohan Talks a lot about them in
https://www.amazon.com/gp/aw/d/1546603131/ref=mp_s_a_1_1?ie=UTF8&qid=1510177377&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=lost+art+of+steam+heating&dpPl=1&dpID=51ERTW8M69L&ref=plSrch
He even talks about a friend of mine @izhadano and what he did with his 1 pipe steam system.

Base board is great with 2 pipe steam. Somebody correct me if I'm wrong, I believe you only need 1" of pitch for every 20' when steam and condensate are flowing in the same direction.
You will always get more heat from radiators filled with steam then HW thanks to the latent heat you get with steam. With Burnham CI baseboard filled with steam at 1 psi (215°F) it has an output of 860 BTU's per foot. With HW at 170° it only has an output of 450 per foot.
That right there you would be cutting your radiator budget in half.
There's also recessed wall Convector If you trying to save floor and wall space.

Steam is king of heating. It always has been because there is no better heating medium that delivers heat as efficiently, completely naturally without being forced.

P1385

This is all great info! Thanks to everyone that has contributed.

Any suggestions on resources to learn about boiler controls? I have a basic understanding but am not familiar with some of the components discussed. Thanks again!

Zman

Go with hot water designed for low temps. For now install a condensing boiler and low temp radiators. I would consider low profile flat panels like Runtal.
The cost of install would likely be less than 1/2 of steam. Energy use will be at least 20% less. It is also a far more friendly DIY project.

The Steam Whisperer

Modern minitube steam systems use copper tubing often about 1/2 to 1/4 ( 3/8 inch soft copper supply tubing and 1/4 inch copper return tubing to heating units) the size for hot water and heating elements or radiators about 1/2 or less the size needed for "high efficiency" hot water ( BTU/ Sqft of radiator is about 250 for modern steam system, but only about 100 for high efficiency hot water systems). You may need a condesate pump for a modern steam system, but you also may not. Installed cost is likely to be the same or less for a modern steam system as a "high efficiency" hot water system.
Electrical use for a "high efficiency" hot water system is about 20 to 30 times more, so if you take into account All energy use, the actual energy usage is very similiar between steam and hot water.
Also condensing hot water boilers tend to be designed for a 15 year life or less and repairs are much more costly. Whether you use steam or hot water... I would stick with much more reliable cast iron or steel boilers, preferably with a modulating burner with a boiler life of 30 to 40 years or more. A standard efficiency hot water boiler will also use on about 15 times more electricity than a steam boiler or about 1/2 or less than a "high efficiency" hot water boiler. High efficiency steam boilers also use more power than standard efficiency steam boilers, but still much less than hot water boiler in general.

Henry

The only problem with steam is the initial installation cost. Once it's in you'll be virtually maintenance free, but it's a long payback. So, lots of upfront cost and difficulty finding someone to do it right, vs baseboard which anyone can do.

The installation costs of steam is very expensive. A steam two pipe system is maintenance intensive as is water treatment depending where you are. An average steam trap has a life expectancy of 10 years. It is very difficult to control emitter output and the radiators cost are out of this world compared to a radiant or baseboard system.

Our experience in replacing steam in commercial and large apartment buildings has shown gas consumption drops of 35 to 50% and reduced maintenance costs. A modcon can supply emitter temperatures from 85F on which much more comfortable than a blast of 240F heat. If you want the ultimate comfort, it is radiant floor with an air handler that can provide AC and filter the air from pets and cooking smells. Here is the ultimate 23 zone radiant
ne

MilanD

So @P1385 - you guys win a lottery or something?

Here's Gerry Gill's copper pipe steam at his home. You can read more about it on his website.

https://youtu.be/U_wLnyul-S0

https://www.gwgillplumbingandheating.com/webapp/p/547/gerry's-own-house-steam-mini-tube-system

This system will be super easy to install as it's all flex copper tubes, 3/8 supply and 1/4 returns. It needs a bit more in moving parts: traps and condensate receiver with a feeder motor. So, a few more moving parts. I wonder if with tall enough basement you could do with a tall loop seal and just a vent in front of it and a regular wet return with dimension B. Maybe a question for Gerry.

jumper

I respect Henry but I think his comments apply to old fashioned steam heating. Closed –no vents– steam heat needs no traps with moving parts and should consume very little if any water. Steam heating is closer to isothermal than HHW can be so it ought to be more efficient.

However where to find people to design,install & maintain steam? That is why I suggest closed gravity HHW. It also has hardly any moving parts and consumes little if any water. I suspect it will use more fuel than steam. But any new construction needs modest amount of heating.

P1385

@MilanD I've tried to inform myself about mini-tube, but my head starts to spin... I'm struggling with how 2" or larger lines use to be needed but now we're getting away with 1/2" copper... I just don't understand. Can you steer me toward an explanation?

Can steam baseboards be used with mini-tubes? This might be a silly question, but I don't know much about the system.

MilanD

@P1385

It's a neat system. I'm also in planning fazes of a steam install and am researching. This mini tube was short lived and from Cleveland area. My understanding is that the pipe being smaller, it moves steam faster than regular iron pipes of larger diameter, thus it has same net effect in btu delivery. Also, as the pipe is smaller for the same amount of steam volume produced by the boiler, steam goes to every radiator with greater ease. Throw a throttle valve on the rad, you have an instant zone too. Copper makes it completely flexible to install anywhere and can be hidden in walls (although I would always leave access points esp. in 2 or 3 story tall installs as is also my own house).

In my mind, downside is need for traps on rads and f&t traps on end of mains, condensate return tank and pump for condensate makeup on the float switch in the boiler. A lot of moving parts there. I still think it's neat, but I person ally would like something simpler and that's why it probably isn't for me. But, that being said, it's awesome how it works.

I think if you do proper heat loss calculation and it shows you'll have enough btu/EDR in the baseboard length to use it, I don't see why you couldn't.

Here is a discussion from a year or two ago. There is select temp brochure that Steamhead posted in one of his responses.

You would want to talk to Gerry Gill about how best to install this. Since it's a 2 pipe (although using copper instead of iron), each rad has a trap on the discharge. I am not sure you can do without like the regular 2 pipe with orifices. Same goes for f&t traps at the end of mains. Not sure if a tall enough loop can substitute to keep back 2-3 psi needed to operate. If psi needs to be 5-6, this will in fact need a very tall loop seal, thus not feasible and trap is needed.

As to high psi, given that main copper tube is 1"od, it would take no time to build pressure even to 5-6 psi, so fuel wouldn't be wasted.

At any rate, give Gerry a call. I'm sure he'd consult you on it.

https://forum.heatinghelp.com/discussion/158571/found-an-iron-fireman-selectemp-system-today

To me, vacuum system is much more interesting. As you see from this thread, some people are seeing amazing vacuum results with lower boiling temps, even heating and autobalancing of rads based on condensing rates, on 90 year old systems. Just amazing. With a new install, you can make it 100% tight, and whether you do 2 pipe with one main vacuum vent (or valve on a solenoid and a plr controller) or 1 pipe with a vacuum pump on lines coming to where vents usually are, you can probably start the system cold once at the beginning of heating season, get into vacuum, and never ever have to worry about vacuum loss nor having to use any pumps. Cost wise, seems like 1 pipe vacuum boost should be least expensive to install: least amount of materials, one vacuum pump for once a year startup, and the rest would be all gravity. Meaning, as long as you have gas, with any power outage, you still have heat (maybe battery or small generator backup for the igniter, or just use standing pilot gas valve, and the same battery or small generator backup on the plr, if used.)

Fun times!

Abracadabra

If it were me... steam mini-tube.. hands down.. no question.

Steamhead

Henry said:

The only problem with steam is the initial installation cost. Once it's in you'll be virtually maintenance free, but it's a long payback. So, lots of upfront cost and difficulty finding someone to do it right, vs baseboard which anyone can do.

The installation costs of steam is very expensive. A steam two pipe system is maintenance intensive as is water treatment depending where you are. An average steam trap has a life expectancy of 10 years. It is very difficult to control emitter output and the radiators cost are out of this world compared to a radiant or baseboard system.

Our experience in replacing steam in commercial and large apartment buildings has shown gas consumption drops of 35 to 50% and reduced maintenance costs. A modcon can supply emitter temperatures from 85F on which much more comfortable than a blast of 240F heat. If you want the ultimate comfort, it is radiant floor with an air handler that can provide AC and filter the air from pets and cooking smells. Here is the ultimate 23 zone radiant
ne

Here we go again. If you want your " gas consumption drops of (sic) 35 to 50%" to mean anything, you need to tell us what condition the steam system was in. This is a major point and one that the rip-steam-out pushers always neglect. I'd be willing to bet the steam systems you've ripped out were in horrible condition.

And don't forget, someone who knows steam can achieve similar savings by fixing the steam. This course of action costs far less than the one you're trying to sell.

For those who weren't around then, here is an earlier thread covering this topic:

https://forum.heatinghelp.com/discussion/145002/actual-savings-over-steam-heating

And, the mini-tube system costs quite a bit less than the usual steam system to install. @gerry gill , @The Steam Whisperer and others can be more specific on this point.

P1385

@Steamhead Thanks for input! I wasn't on this forum when the thread you referenced first happened. That is the type of info I've been looking for.

Thanks!

Steamhead

No problem, that's why I have it bookmarked

The Steam Whisperer

From that bookmarked post and Henry:

"Here is a simple proof of hot water over steam and it is not even a mod-con! A Smith 28-10 hot water boiler or steam has an input of 3,172,000 BTU. The IBR gross in both cases is 2,498,000 BTU. The net IBR for water is 2,172,000 or 68.5% efficiency. While the steam version is 1,939,000 BTU for a net efficiency of 61.1%. Those are facts that you can all look up. "

Statements like this are why I now ignore anything that he posts about the efficiency of hot water versus steam. Those net numbers reflect a pick up factor of about 15% for hot water and about 33% for steam to account for the warming up of pipes and piping loses. Just check the manufacturer's literature or any basic information on boiler sizing. I have many steam systems where the pick up factor is only 10% or 15%. So does that mean the boiler is suddenly over 7% more efficient...NO! I have hot water systems in which I used no pickup factor at all, so are they suddenly 12% more efficient...again NO!
Pick up factors are arbitrary numbers used by the industry to account for an average system's need for fast warm up and piping losses, nothing more.
If you research and find the few boilers that are actually tested for output on steam and then tested for output for hot water (like the peerless 63/64 series) you will usually see about a 1 to 1 1/2 percent reduction in conversion efficiency with steam versus hot water.
Hot water in the field typically does have a slight advantage in efficiency due to potentially lower pick up factors for many older systems ( lower pick up factors mean smaller boilers which mean lower stand by losses), however, with the very compact and extremely low mass distribution system of a steam minitube system, the pick up factor will be smaller for the steam system than typical hot water systems. Gerry gill can address this best with his own system. Mine is still in design mode and will be modified version of a minitube system in order to eliminate the condensate pump and radiator traps, so the only mechanical devices will the boiler stack damper, pressure control, gas valve and maybe a low water cut off (if I decide to set it up to work without any electricity).

jumper

Boiler is only one component of heating system. HHW circulates thirty times as much heating medium as steam.

Henry compares extensively modernized HHW to older steam. I'm not certain that he's up to date about two pipe steam being more expensive to install or that it uses more water than HHW. I see a lot of equipment(filters,strainers,DI) advertised for dealing with water conditioning for HHW.

That being said,my advice to OP is HHW because knowledgeable steamies who'll work on small buildings are rare. Toronto is a HHW city but many young techies servicing houses don't even know HHW that well. Go look into the radiant section to see how many unnecessary troubles there are.

jumper

Henry,I hear about steam heated apartments dramatically reducing gas consumption by installing TRVs. You can use steel panels for new work: are they more expensive than baseboard?

Henry said:

The only problem with steam is the initial installation cost. Once it's in you'll be virtually maintenance free, but it's a long payback. So, lots of upfront cost and difficulty finding someone to do it right, vs baseboard which anyone can do.

The installation costs of steam is very expensive. A steam two pipe system is maintenance intensive as is water treatment depending where you are. An average steam trap has a life expectancy of 10 years. It is very difficult to control emitter output and the radiators cost are out of this world compared to a radiant or baseboard system.

Our experience in replacing steam in commercial and large apartment buildings has shown gas consumption drops of 35 to 50% and reduced maintenance costs. A modcon can supply emitter temperatures from 85F on which much more comfortable than a blast of 240F heat. If you want the ultimate comfort, it is radiant floor with an air handler that can provide AC and filter the air from pets and cooking smells. Here is the ultimate 23 zone radiant
ne