Steam or water system for old Hotel

tim smith

Just met client at new building he bought. 100+ year old building. appx 24 rooms upstairs where old cast iron steam only rads had previously heated it.  He still has radiators  but all piping has been removed and old boiler gone. Start from scratch. He is not upgrading buiding as far as windows, insulating walls etc. He would probably insulate attic as all this work is on 2nd floor. Main piping can be ran in 16ft high retail spaces below and the branches up to each small artist work rooms(ie old hotel rooms. 200sft appx each.  Interesting concept that we have radiators already and he would entertain new 1 or 2  pipe steam system.  Or spend the extra $$ and buy new wall panel radiators.  Steamhead, any others, input would be great as to consensus. Cost is of course concern but not totally decision maker.  Aesthetics are part of it also.  Thanks, Tim

Henry

Radiators

Can you convert the radiators to a hot water system? IE, do they have available two connections? Don't worry about the difference in BTU output over steam to water! We have converted a few commercial buildings to hot water. Don't forget the original radiators were considerably over sized! By going with a mod-con and hot water, energy use will be nearly 50% less and virtually no maintenance compared to steam.

LarryC

Questions

Location of building?



Design temperature and need for modulation of heating plant?



Does the landlord want individual room temperature control?



Fuel preference?



Any future plans for adding other heat sources like solar, geothermal, wood, or other solid fuels?



Desire for A/C in retail space or rental spaces?



Limitations on time of day when the building is occupied? 

Jamie Hall

Well...

Have to admit that I disagree with Henry's comments on fuel savings.  A BTU is a BTU, whether it gets there by steam, hot water, or air, and the BTU loss of the building will determine the number of BTUs needed to fire the boiler or whatever -- within rather narrow limits.  A modcon is more efficient, but only when it is operating condensing; year round it might beat steam by a couple of percent.  Not more.



That said, however, his first question is very important: can you convert the radiators?  Most of the time the answer is yes, with some work.  Sometimes it's no.



Most steam systems were overdesigned; you might be able to get away with the reduced output of hot water -- but you should check.  Surprises in this regard are not fun for the contractor.  Further, it affects the efficiency of a modcon, if you are looking that way -- if they have to run 180 degree water, you're not going to get the advertised.



Larry's comment on other heat sources is very well taken.  Hot water lends itself to a nice wide range of alternates, such as solar.  Steam does not.

Brian_19

Bad info

"A modcon is more efficient, but only when it is operating condensing; year round it might beat steam by a couple of percent.  Not more"

 How many Mod Cons have you installed that brought you to this conclusion? I found in all of my installations my customers saved  30% minimum in gas consumption.

Jamie Hall

Apples vs. apples

A modcon, conservatively installed so that it can, in fact, operate in condensing mode all or almost all the time, may be able to achieve a thermal conversion of as much as 93%, provided it is properly tuned and maintained.  A steam boiler of similar vintage, properly tuned and maintained, can achieve a thermal conversion of about 85%.  The difference is 8%, and I will grant that difference quite happily.



However.  If the modcon is replacing a twenty year old steam boiler, you will get a saving of perhaps as much as 30%.  But is this fair?  No.  You could achieve a 25% saving (min) by replacing the old steamer with a new one.  So the correct comparison is between new stearmer (85% efficiency) vs. new modcon and changes to the system to achieve maximum efficiency (93% efficiency).

Brian_19

More bad info

Jamie, have you ever installed a Mod Con boiler?  I would like to know how you achieve these numbers.

nicholas bonham-carter

true comparison

the only way to solve this ancient dispute between wet-heads and steammies, is to build 2 identical houses, and put steam in one and a mod-con in the other.

maybe if my number comes up in the lottery tomorrow, i will do just that.

certainly there are plenty of instances where an old, badly maintained steam boiler has been replaced with some other form of heat, and the installer points the accusing finger at steam in general, saying "inefficient, uneven, noisy, etc."

i looked around a show-house with the disconnected boiler still in place, and saw the pressuretrol had been set to 10 psi! the new owner was telling me how much more efficient his new geothermal system was, than the old noisy steam!--nbc

gennady

modcon efficiency

the main difference between conventional heating systems( hot water and steam ) and condensing modulating boiler is not in a boiler efficiency , but in system efficiency. Modulating boiler tracks load very tight, no overshooting at all, and provides exact heat as needed, while standard systems always overshoot the set points.

Jamie Hall

I would appreciate

not being referred to as "bad info" and "more bad info".  Please read what I have written.  I stand by my numbers.

Steamhead

Unless I miss my guess

he will take the cheap way out and install PTACs, ruining yet another beautiful old building. Whenever someone says cost is a consideration, that's how the story ends- they always go cheap.



Nick, every single `case study` I've seen has been as you describe. A steam system near death from neglect, compared to a brand-new mod-con. School systems are notorious for this- makes me wonder how badly the mod-con will run with that kind of neglect. Yet some of us take these bogus studies as gospel.



Steamhead, currently in Japan

nicholas bonham-carter

Another question about this project

How can you avoid the possibility of doing a lot of free design work on projects like this, and then having your plan "shopped around" for the cheapest price?

It could even happen that the low-ball bidder would use some short-cuts rendering the system ineffective.

Maybe the best action to take would be to do the design for a fee, and then put it out for bids.

Steamhead, I marvel at your dedication to the wall that you can still attend here while so far away!--NBC

Jean-David Beyer

Design fee.

I guess charging a design fee is done in certain businesses and not in others.



When I wanted to remodel my kitchen (eventually cost more than replacing my boiler), some contractors charged a design fee, and some did not. The first contractor I went to (recommended by a friend) did not charge a design fee. An agent for that company came out and looked around the existing kitchen. We talked a little bit, and a couple of months later he presented me with a proposed contract that was so vague that I did not really know what he was going to do. $12,000. But I could never sign a contract like that, since it really gave me no clue what he was going to do.



Friends recommended a second contractor. That contractor charged a $500 design fee right up front. The fee was applicable to the job if I went with them; otherwise it was not refundable. Seemed more professional to me. They measured the kitchen, including where the doors and windows were. The next day, they had all that in their computer with a CAD program in it, It had a database of cabinets, prices, etc., in it. I went in and saw their first proposal, and did not like it. Their designer and I spent an hour or so modifying things, and they came up with a price. Almost triple the first contractor's price, but at least I knew what they were actually proposing. There were a couple of things I did not care for and we did another design . The final result was not ideal either, but I knew the reasons they proposed what they did, and because of the structure of the house, it pretty much had to be the way they proposed it that way.  I eventually went with that contractor, the price came in at what they said. The triple price was partly due to all new appliances (existing ones were about 50 years old and had to go. The existing kitchen had to be completely gutted. Moved a sink from one wall to another, Moved the stove from one wall to another, Blocked off a door that was only 18" wide. Things like that. It is actually quite nice now, and I can actually use it, which was not the case with the old one. It was well worth the $500 design fee.



You have heard of some of my adventures with my former heating contractor who supplied and installed my now three year old mod-con. And why his company is now my former heating contractor. They did not charge a design fee. They also did not calculate a heat loss, and several other things.



Basically, if something needs designing, I think a design fee should be charged. If the contractor credits the fee to the cost of the system, that is nice. But there is considerable work involved, and it should not be free.

gennady

design fee

You are absolutely right, design fee must be charged. we do it all the time , except the job is standard and repetitive, and some options can be included in proposal. we always charge fee for complicated or non standard jobs.

Brian_19

answer the question

Jamie again I ask. Have you ever installed a modulating condensing boiler?  

tim smith

Re: ?? Radiators are steam only

That is really the only reason why the question comes up for me. Radiators are already there on site and would not have to be purchased. Client is somewhat budget wary.  OD design here is 24 degrees. Retail spaces not included in this part of job. Heat only, probably artist work lofts.

tim smith

Re: ?? Radiators are steam only

That is really the only reason why the question comes up for me. Radiators are already there on site and would not have to be purchased. Client is somewhat budget wary.  OD design here is 24 degrees. Retail spaces not included in this part of job. Heat only, probably artist work lofts.

tim smith

Re: modcon vs steam (new)

I do a lot of multi family jobs, I am a big fan of multiple modcons. Be that said, I agree with Jamie, if all things created equal, new boilers steam or water, well planned and laid out system, The difference might be only 10 to 15% over all system efficiency. I too get appx 30% efficiency savings when I put in new modcons replacing old cast iron or firetube boilers. When we install new steam boilers in buildings, I seem to remember we may see 10% or so change. The net then I think is closer to what Jamie says in efficiency. We are in a very good climate here in Seattle for modcons, average winter temp 47 degrees with very few sub freeze days annually. This job is not all about dollars as client does want to maintain some integrity of building architecture. Now he is not going overboard also. I think this job will either be boiler or all electric heat (god help us). I will not end up designing whole job before getting job but will have a good handle on it when I quote it.  Thanks for all the input. All is welcome and none is wrong!

tim smith

Answer to questions, Natural gas

Does not care about individual control except probably thermostatic vents or the like depending on steam  1 or 2 pipe or water.  a/c for lofts not needed.

Jamie Hall

for reference and information

for Brian, and whoever else might be interested.



No, I have never installed a mod/con system myself.  Nor have I installed a steam system, nor a forced air system, nor a mini-split, nor a heat pump...



I carry no specific brief for any particular form of heat.  I am a Professional Engineer, now retired.  Part of the ethical code for professional engineers, to which I subscribe, requires that we endeavour to evaluate, design, and recommend the best and most effective solution, selected from available technology, to whatever problem our client presents us with, and over the five some decades during which I practiced, I tried, to the best of my ability, to do exactly that.



I am not and never was in the business of selling or installing this or that, nor have I ever taken a fee or commission of any kind based on recommending one sort of solution over another.  This, too, is part of the professional engineers' code.



I hope, that if one takes a look at the various posts which I have made on the Wall over the years, that one would find that I have made recommendations in favour of almost all possible heating systems, based solely on the best evaluation I can make of the problem presented, rather than on either a preference for one type of system or another or, worse, a financial or dealer/installer type of interest in one type of system or another.



Thank you.

Henry

Steam & Mod/con

One is very mistaken when looking at boiler efficiency and not system efficiency. Our mod/con replacements vary between 30  and 50% in savings over the previous 5 year average. Besides the apartment buildings, commercial buildings we do replacements on average 5 schools each summer with mod/con. The design temperature here is -20F. They do work otherwise the shool boards who not spend the funds. Our average boiler operating hours has dropped from 1200 hours to 1050 hours of which a maximum of 200 hours is at high temperature. Therefore, the boilers will condense most of the time if, one has a proper design with the right pumps. One of the tricks in designing a heating system is to micro manage the load. We prefer to use several boilers over one or two large boilers. It is a bit more expensive but it is better to have 10 or 15 to 1 firing ratios than just 5.

We also know that all cast iron radiators designs here, have over capacity as they were designed to heat with a window open. Remember: "In Flu Enza"? Weare presently re piping the Northern Electric building on a multi million$$$ project. It was a one pipe hot water system. Yes, one pipe gravity hot water system! The mains went to the top floor and the risers went down 10 stories. The cast iron radiators were connected on the same side with a Y type of tee. The new boilers will be De Dietrich mod/con and we will have variable load sensing pumps pumps on the various branches of the building as there will be now thermostatic valves on each radiator.

On average, changing over from a steam system to a hot water system saves 50%! Those are facts in our cold climate! Steam should be used for process work. If anyone disagrees with this, please provide some facts and numbers. I am sure that nobody can proove that steam is more economical to heat with! And once more, what about all the maintenance issues?

gennady

Re: professional engineer

I did remove this post and do apologize for it.

Steamhead

You fail to mention

what condition the steam systems were in. I'd be willing to bet they were in relatively bad shape.



We've been down this road before. Here are some links to previous threads on the subject- note that some are from the previous Wall so the posts are slightly scrambled:



http://www.heatinghelp.com/forum-thread/90787/Steam-to-warm-water-conversions-cost-3-times-less-to-operate



http://www.heatinghelp.com/forum-thread/126167/Converting-steam-to-hot-water-system



http://www.heatinghelp.com/forum-thread/98194/Converting-Steam-to-Hot-Water



http://www.heatinghelp.com/forum-thread/115513/Steam-System-Savings-Without-Converting-Steamhead



http://www.heatinghelp.com/forum-thread/123650/Dan-Its-Time-To-Look-To-The-Future

Steamhead

That remark

was uncalled for, to say the least!

alotlikeearl

Shocked!

I am shocked and disappointed in the tone this thread has taken.  I have enjoyed learning from this site and have always appreciated the respectful way people express their opinions.  I don't know if there is a full moon or what, but this thread disappoints.  I think the disagreement is due to  miscommunication.  To Jamie, thanks for your always thoughtful approach to questions.  I have learned a lot from your experience based replies.

                            Jerry 

BobC

steam can be efficient

I think the numbers speak for themselves; a modcon can be 93% when it is condensing and a wet based steam boiler is 85%. In both cases it's important to match the boiler to the load and the controls to the specific conditions a job calls for.



I have a 90 yr old steam system with a 16 yr old boiler and it runs pretty well, the temperature stays within about a 2 degree band of the thermostat setting. I've used 244 gallons of oil (October to today) to heat a 1150 sq ft house one block from the Atlantic ocean just south of Boston. I do use a small electric heater when I'm watching TV or reading in the evenings (2-3 kw per day average). My only oil delivery this season was in early January, I usually go through about 350 gallons of oil a season, this year has been very kind and I'm sure we will pay for it at some point.



Because the piping has been ripped out it is probably more cost efficient to go with forced hot water heat because of the costs involved with replacing all that threaded steel pipe in this case.



We all have our opinions on what works best and it's good to trade information so we all can benefit. I've used this forum for a while now and I've always been impressed with

the knowledge of the participants and their willingness to help people who are trying to understand whatever heating system they have.



In this kind of forum it is important to respect the opinions of others, there is nothing to be gained by attacking forum members. We are all free to disagree but do so respectfully.



Bob

Henry

Steam efficiencies

One cannot compare boiler efficiencies for system efficiencies! But one can make an existing steam system more efficient. I was at a property manager last week. We replaced a Smith 28A-9 that was destroyed due to an improper install (no swing joints on the (headder) and chemicals (that damaged the faces where the gasket sit). We replaced the boiler with a Smith 28A-9 HE. It is only a few percentage points higher combustion efficiency. We also installed a proper mechanical combustion air  that pressurized the boiler room. But, we reduced the pressure to 2 PSI and installed a modulating burner. The condo unit went from a 197,000 cubic meter 5 year average to 160,000 CM in the past 12 months. The unit was only installed in late September, so the savings should be better. They saved so far $15K! As only one side of the condo has a somewhat working vacuum system as the other side's control panel is kaput. We will install two Heat Timer controls to control the vacuum pumps with outdoor reset. They will pay for themselves within two years.

Again,it is system efficiency that counts!

BobC

I agree

Boiler efficiency is only one part of the picture, all elements must be tuned to support each other for optimum system efficiency in any heating system.



Bob

The Steam Whisperer (Formerly Boilerpro)

Alternative to black pipe for steam...

I'd look closely at Gerry Gills Steam mini tube system for repiping the system with very small copper.   Youdd get the benefits of steam, with the lower installed cost of copper.

tim smith

Thanks all for the input???

I appreciate all the input on this. I should have known it would spark a debate. It is always interesting to learn more from all the opinions/knowledge here. I wish I had two identical building to redo and compare. I do have quite a few buildings that we have redone boilers in. I am going to get a hold of my clients and have them pull their gas records for the ones with modcons and the ones with new Steamers. Their are several 30 unit buildings I can compare each other to.  Thanks again. Tim  (Ps, don't know if I am closer to decision or not but been fun).

rich pickering

System % vs AFUE

Don't know about the steam minitube but it sounds interesting. 

Another consideration.  What is the condition of the rads, specifically the threads?

We have a similar situation here. We are doing a church this summer. Old 600,000 btu steam boiler that is in decent shape. 

It is being replaced with 2 Vitodens with odr, Grundfos magna system pumps and panel rads with txv.  So, modulating boilers, modulating pumps, modulating rads with individual temp control and modulating water temps. If anybody can tell me what else to add to improve system efficency, I'm open to suggestions

About 60' of piping will be 2 1/2" black grooved, the rest will be 1 1/2" wirsbo with 3/4 wirsbo runouts and 1/2 copper drops from the rads.  The labour costs are reduced with this piping.

Some other factors.  No more stack losses up a huge chimney.  Depending on your jurisdiction you may need an operator for the steam boiler, but not the modcons.  Our boiler inspectors won't even look at a small modcon anymore, so no costs with having to be there with the inspector. Modcons don't generally have the same maint costs as  steamers. 

The surface temps of the panel rads will be decreased. This is huge in terms of liability and some codes.  Our surface temp of any exposed surface is not to exceed 120.  (IIRC)  It is possible to build covers for CI rads, but that is an additional cost.

Comfort levels should increase.

Downside?  While the gas bill should go down,  electrical will go up, but they should be money ahead.   Repair parts for some modcons  can be expensive.  Not to much of a stretch to say that the most expensive part on the steamer is cheaper than the cheapest part of the modcon. I'm adding a lwco to protect the pumps, those puppies ain't cheap.



As a disclaimer, this steam boiler is the first one I ever worked on.  I love this boiler, but it's time has come.  The old gauge is going on the new system as a tribute to the dead men.