Oil-to-gas conversion for steam system

marcl

We are looking to overhaul our "antique" heating system and would appreciate expert guidance.

The home has no air conditioning currently, and maintains an oil-fueled ~20-year old Dunkirk steam boiler for heating. The home was built in 1760, and maintains 1919 and 1940 extensions. The 1940 extension (kitchen, laundry room, living area, and garage) will be completely renovated. The 2-pipe steam system services the entire home (3,300 sq. ft.) currently, and we are looking to convert from an oil to a gas boiler, keeping the existing piping (converting to water raises concerns of leaking if system pressure increases), and decommissioning the oil boiler and oil water heater. We’d also like to add A/C (HV or forced air) to the first floor as the ceiling below is open, making the job easier. The second floor has no attic or ceiling space, making that job a challenge.
1. Is this approach sound?
2. If so, what high-quality, high-efficiency gas boilers exist? We are considering systems like. Burnham IN7S-EI-EZ-NG, Peerless 63-06-SPRK, or Slant-Fin’s Galaxy GXHA and an opinion on these or other systems would help.
3. Is there a way to take advantage of the heating power of the steam boiler to heat hot water or should we go with a direct heating tank-less system?
4. Any suggestions for a HV A/C system or are Spacepak and Unico the only players in this space?

KC_Jones

Have you considered just converting your existing boiler to gas? If it's in decent shape you could have a gas gun conversion installed in it for a lot less than an entirely new boiler would cost. If the boiler fails down the road you could reuse the gas burner in a new boiler so the money wouldn't be lost. As far as AC goes have you done any research on mini split systems? They are much easier to install in a retrofit situation such as yours. I am curious though, how is it that you don't have an attic? Is this house a flat roof?

SWEI

Sounds like you have a wonderful house and a pretty good handle on the path you need to take. Where are you located?

bio_guy

In looking at mini splits don't get centered on the most common high wall units only. Look at ceiling units and the minimally-ducted small air handlers.

marcl

Thanks folks, and sorry for the delayed response. I did not have notifications configured properly, but now I do! The house is in the Old Hill historic district of Westport.

KC_Jones - That's a good point, but unfortunately the unit only has a few years left (if it can even be converted), and we're looking to install an efficient gas boiler which will last for decades to come. And then there's the water heater component that we want to address also.

No attic because the 1760/1919 parts of the house have cathedral ceilings with exposed hand-hewn rafters and collar ties. We don't even have much room between the roof deck and plaster ceilings for insulation.

We plan to strip and replace the entire roof this summer, restore all the single-pane windows, insulate, and get the new gas boiler/water heater in. We'll do the a/c too if there's time, but may delay that until the fall since we won't get it in before summer when we'll need it.

I've heard good things about the Burnham Megasteam which is 86% efficient, but I don't think there's a gas version. Would it be foolish to consider going with an oil system like that if we have a gas option? It appears that the most efficient gas steam boiler is 82%.

Assuming we're eliminating all oil, it appears it will come down to a WM, Peerless, or Burnham based on my research. And as anyone reading this post would probably agree, the boiler is only part of the equation. A quality installation is equally important.

Jack

I'd vote mini splits over hiV. More efficient and quieter. I'd also separate the DHW from the steam system.

This sounds like a BIG project. I just finished this for my CA antique home. At the end of the project I thanked my architect and told him he only neglected to tell me one thing at the beginning of the project. He asked what that was and I told him he should have advised me to buy 150' of stout chain and a 20 ton chain fall and to squeeze the house until it was in a pile. Then re-build it just like it was. It probably wouldn't have cost any more to do it.

Another thought. We, my wife and I, lived in the place through the remodel. In retrospect, which is always more expensive, given the schedule issues around keeping the house functional vs getting on with it, I think I could have bought a 25' Airstream and netted the cost of the Airstream in building construction efficiency. Too late smart, in my case!

marcl

Jack - Shhhh... Don't let the Historic District Commission hear you. Or my wife for that matter since she wants to rebuild over preserve/restore. But that decision tugs on the heartstrings of purists.

vaporvac

What edr is this system? Please don't forget the Slantfin Intrepids. I'm very happy with my set up. Many of us here with wet-based boilers have achieved 84% + efficiency with gas. Their near boiler piping instructions are exacting and all mention a dropped header. Don't worry about your wife...she'll thank you later! New is never like old, try as one might. I always appreciated the old, but that has only increased with time. Colleen

marcl

Thanks Colleen. I'm in your camp on preserving. Since mentioning Slatfin in my original post, the installers with whom I've spoken mentioned that Slatfin makes good products, however, they've had trouble with support. I don't know if that's just coincidence or if this region has trouble with Slatfin support. Most friends in the area, have had good success with Burnham, Peerless, and WM.

Steamhead

We install Slant/Fin Intrepid steamers with Carlin EZ-Gas (mostly) or Midco EC (a few) gas burners. They run well with these units.

Don't know if anyone has noticed, but S/F has added flueway baffles to current-model Intrepids. These not only make them run more quietly, but also more efficiently by reducing the stack temperature. So for those who noted that these boiler/burner combinations can be a bit loud- they listened, and did something about it. We've retrofitted baffles to a couple Intrepids, with favorable results. In one case we dropped the stack temp by about 140 degrees!

We haven't needed S/F's support for our Intrepids, but have used them to get specs, fireboxes etc for a few of their older units. On these occasions, they've done well. S/F has also expedited boiler shipments when we've needed one quickly.

So I'd say Slant/Fin is a stand-up company that we like to deal with. But I sure wish they'd come out with a three-pass, gas- or oil-fired steamer ;-)

marcl

Steamhead - Do the Intrepids come in a Gas/Steam version? I only came across the S/F Galaxy GXHA in Gas/Steam.

Steamhead

Yes, S/F has approved the use of gas burners in the Intrepid boiler series, but they don't advertise this. The ordering procedure is to order the boiler without the oil burner, then order the gas burner from Carlin or Midco. Our inside-sales guy has this down to a science.

Here are some threads where you can see some of these boiler jobs. Some contain more than one installation, so be sure to scroll all the way down:

http://forum.heatinghelp.com/discussion/151822/two-recent-steamers#latest

http://forum.heatinghelp.com/discussion/151228/not-the-usual-failure#latest

http://forum.heatinghelp.com/discussion/150537/three-recent-steamers#latest

http://forum.heatinghelp.com/discussion/139545/a-special-intrepid-ez-gas-steamer#latest

etc. etc. etc.

marcl

Cool, thanks! Since the S/F support was my concern after speaking with local installers, would having an unadvertised configuration exacerbate that issue. I assume you are happy with S/F support, so do you think the support issue is regional? Trying to understand if the local folks are really having issues with S/F.

vaporvac

Please read my post"I hear a Trane a comin'". SF was OUTSTANDING helping me with my design. Their tech support can't be beat. Just call them direct. The gas versions have separate piping instructions that they'll email you. Be sure you call tech and tell them what you're doing and they'll take care of you and review your piping plans. Follow the install install to the T and you'll be good.
I used the Reillo G400 burner for my TR50s as it was a bit quieter. Depending on the size of your boiler, there are also a couple of burners that are two-staged for a finer and more economical functioning.
Thanks for the heads-up, Steamhead. When did they start doing this...I just put mine in 2013/14. Would this help and is it a big deal fitting them? I presume this is a job for a pro?
Honestly, I figured this out myself with the help here and at SF, so I'm sure pros could do it. You just have to read the instructions and know how to use a combustion analyzer. T he intrepids are wonderful boilers.
I had a bit of the same problem, but I would persist. You only get one chance to do it right, why not do it best. They're the same price approx and the piping may be different, but not harder. Post some pics of you guys' work for folks here to critique. Maybe that's the problem.

Steamhead

vaporvac said:

Thanks for the heads-up, Steamhead. When did they start doing this...I just put mine in 2013/14. Would this help and is it a big deal fitting them? I presume this is a job for a pro?

You may already have them. Remove the smoke pipe from the boiler and shine a light down into the opening. If there are baffles, they will be hanging in between the sections.

marcl

Looks like we're back to square one on this project. We had 6 reputable installers come through and all said to forget about a forced air (including high-velocity) system. Not enough space, and too much "old house" would be destroyed getting it in. Basically, they all said, "This house wants a hydronic system." So we're scrapping the thought of AC (it hasn't had it for 250 years anyway), and sticking with the radiators. But here's the issue. Nobody can (lack of expertise) or wants to (unclear why) take on an oil-to-gas/steam-to-water conversion. The system is a standard 2-pipe vapor system with a full open space in the basement, with a dedicate flue for exhaust. I've run a number of home projects, even GC'ed major projects in our own house quite effectively for years, but I have never been challenged in finding a contractor like I am with this. And we're in New England! Even some bigger local names aren't willing to quote this job. I wish Dan Holahan was free to come down and do it. Anyone have any thoughts?

KC_Jones

Why are you even thinking about converting from steam to hot water? Many of the pros on here will tell you that is a sticky road to go down. Steam runs at very low pressure and if you convert to water you will now run at a much higher pressure risky leaks. It honestly doesn't surprise me that no one wants to quote a conversion to water. If you have 2 pipe vapor system those are the cadillac of steam heating you should keep it. As far as AC again I will suggest the mini split option.

Jamie Hall

Keep the steam! Don't let those idiots sell you hydronic -- they are either lazy or misinformed. Or worse.

This is Westport, CT, I presume? Then you are within range of Charles Garrity, 413-841-6726. He does an excellent job of bringing steam systems up to speed. Give him a call.

marcl

I am concerned that nobody will know how to service steam in 20 years, since folks are afraid to touch it now. I was prepared to learn the system myself, and deal with it, but there are a number of factors dissuading me from that. There's also the efficiency issue and long-term savings with going to a modulating gas water system. I should also be more precise in indicating that the current system is vapor, not steam. I completely understand that going to water might pose leaking issues, which is why I didn't want to convert initially. But if I bite the bullet now and fix what leaks, the water system should be sound going forward.

I have left a message for Charles, and hope to hear from him soon. Thanks Jamie!

KC - Regarding the AC, we did look at those split systems, and they pose an installation challenge. We had two of the companies that came out say that they could do it, but given the number of cooling days, the cosmetic concerns with the HDC, etc., it didn't make sense. 3 window units for 6 weeks/year will work. The house is otherwise quite cool and stays that way with some fans.

This has been very helpful. I will post what Charles says soon.

ChrisJ

The efficiency difference between modulating hot water and a properly working steam system is so tiny even your grandchildren won't see a return on your investment.

Have Mr Garrity fix the steam system and spend any left over money on tightening up and insulating the house. You'll save far more money that way.

vaporvac

I feel both compelled an qualified to answer. I'm so mad I could spit, but feel sick at the same time as I was given the same line a few years ago and almost fell for it until I realized money and ignorance was the driving force behind it all. I could have bought another house for the amount extra it would have cost.

I also have a vapor system (vapor/vacuum, actually) which is just another name for low pressure steam. You have a steam system. There's nothing magical that any contractor has to do to convert to gas. The magic was done when the system was installed.

There is hardly anything to maintaining a steam system. In my more paranoid moments, I think that's why folks like one to convert to HW: it requires a lot of stuff that can fail and need replacing! It's not like water is a set-up and walk-away proposition. Besides the eventuality of leaking pipes, you also have the real worry of frozen pipes. Read some of the posts from this winter to see how that worked out for quite a few people. Or just read @josieT 's post to see what a cold disaster she has on her hands as a result of a hydro conversion. Modulating systems only achieve the touted efficiencies in warmer weather....you'll never see them in a cold New England winter. Plus, there is the added electricity and chance of failure inherent in using pumps, not to mention the shorter lifespan of these boilers. You'll probably be thinking about your third replacement mod/con by the time a cast iron steam boiler is even thinking about failing.

Apparently, the conversion to gas isn't the issue as there's no modulating boiler using oil of which I'm aware. You'll need to line your chimney, but that will be the case with any gas appliance. You'll need a new boiler with a double-barometric draft *or at least add a conversion burner to the existing boiler if that's possible)...I've already mentioned the wet-based boilers with approved gas conversion burners. There's really no price differential between these and the older atmospheric types. I'd suggest getting a multi-setting burner for even better efficiency. These choices would get you in the ballpark of a mod/con's best efficiencies, but remember, the mod/con only gets that some of the time, not in cold weather. The main gain is the conversion to gas.

I'll have to re-read you post as it's possible you also have a vacuum system. Call Charles. I really feel I dodged a bullet and now thanks to the help of lay and pro from this site, I have the best system I could ask for. Please benefit by the combined experience here. If HW were better, I suspect they would have converted the empire state building during its recent renovations, but they didn't!

You have time to find a proper person to do this. Stick to your guns. Besides the changes necessary for a change-over to gas, the boiler install is a matter of following the instruction manual. Even I was able to do that. The fact that your system is vapor has NOTHING to do with the change-over or new boiler (except you'll want a vaporstat and run it at oz of pressure at most). The important work was done 100years ago when they designed and installed all the pipin. They tried to hand me this line as well, somehow indicating that a vapor system required a different boiler install. So sorry to read this post. Colleen

vaporvac

Is there any chance you could post pics of your near boiler piping from a distance and a couple of pics of a representative radiator?

ChrisJ

uh oh.
You upset The Colleen.

vaporvac

I can't help myself. I just feel so bad for the HOs such as @josieT . They are the cautionary tales of going this route. Plus, there would be zero monies left for any insulation upgrades which is what really counts.

marcl

Colleen - You need to come out of your shell and tell us how you really feel! ; )

In my initial post, I communicated that we did not want to convert to water, only to gas. The system is silent, save the noisy boiler, there are no leaks, and it heats wonderfully. The boiler, however, must go with the o2g conversion, and it's 20+ years old anyway, so I'm not shedding a tear. But the steam system is a champ. The issue, however, was that everyone who came in to give me quote on a new boiler couldn't/didn't want to support a steam (vapor) system. Ultimately, we focused on water, but that also scared folks, for a variety of reasons. Core to all of them was likely ignorance. That led me to this site again, hoping for a reliable installer that knew what he was doing. Mission accomplished!

My intentions are to:

1. Thank everyone on this post for their excellent guidance.
2. Buy Dan Holohan's steam books.
3. Have Charles Garrity over next week for a look.
4. Select a Peerless, Burnham, or Weil-McLain steam boiler and a good gas water heater, then learn them inside and out, with Charles' assistance, for ongoing maintenance.
5. Determine if I can use WiFi-enable thermostats on the radiator valves for discrete control.
6. Do the o2g conversion with the new boiler and water heater.
7. Enjoy steam this winter, and for many decades to come.

I've included some pics. If anyone feels I'm not taking the right steps, please let me know.

Jamie Hall

I'm so glad you got hold of Charles and got him on board! And a Broomell system -- they were, and are, one of the best vapour steam systems.

In fact, three cheers!

Steamhead

Agreed. You can't go wrong with Charlie, and the Broomell is an excellent system.

Rich_49

I might suggest an HTP Phoenix for your domestic hot water .

marcl

Thanks everyone! And Jamie, thank you for passing along Charles' contact info!

BobC

My house is over 90 years old and ha single pipe steam system, I bought the house 34 years ago and it had a Delco oil fired steam boiler that was too big but seemed to work well. I have since replaced the boiler (now gas fired) and in all those 34 years I have had one repair done by a heating contractor; that was replacing the primary controller. I have replaced vents and repacked valve stems but other than getting the system cleaned every year that was it.

I'll put my repair record up against any hot water system. If a steam system is configured correctly they run VERY reliably.

Bob

marcl

Now that I know our 100-year old steam system will be in good hands, and we've had a few days of hot weather, I started thinking about cooling again. I came across an article online (http://www.oldhouseweb.com/blog/how-to-cool-your-house-without-air-conditioning) that spoke about cooling without A/C. Counterintuitively, it recommends shutting all windows save one in the basement, and one on the top floor, adding a window fan there to help with air flow and exhaust the rising hot air. Conceptually, this sounded neat because the cool air from the basement would be drawn upward and the hot air released, so I tried it. It actually works! Within an hour, most areas of the house were 10 degrees cooler, and that was as the day was getting warmer. It's like free A/C! I wonder, however, if like geothermal, the coolness of the basement is drawn out over time. Given that our nights are cool, and the subterranean stone foundation, I don't expect that to happen. I thought I'd pass this along as it's one of the best finds I've had in a while. Well, OK, since Charles Garrity. ; )

ChrisJ

I've heard of this but I'd never do it at least not in my area for several reasons.

1: my basement has mostly a dirt floor and a stone foundation, the amount of moisture down there is crazy even with a dehumidifier going 24\7.

2: it gets very humid here at night, often to the point of being foggy. When it's 70-80F and foggy out I don't want that in my house.

3: I like cold. Anything above 75F and I'm miserable even if it's not humid. I run my A\C at 68F often and have fans on.

Yes, I'm weird and I'm ok with that.

marcl

With that moisture, this probably won't work. I put a dehumidifier in our basement and it's been bone-dry since. I'll see how this works on a hot rainy August day. But if it doesn't, that's what the back-up window A/C units are for!

SWEI

Whole house fan, anyone?

BobC

Using the cool basement air works early in the season before the hot and humid air hits but my basement is pretty humid so once you get into late June that just won't work.

I put in a large window fan (1/6 HP?) in an upstairs south facing window and i open up a window on the first floor on a shady side of the house. I close doors on the first floor so air flows through all 3 rooms and it works fine on most days. I usually run it on low or medium speed all day (I'm retired), if it gets into the upper 80's or really humid I run a large window AC on the first floor and keep it at about 72. If I can be cool and dry during the day it does not bother me having to sleep in a warm bedroom that rarely gets above the low 80's at night.

Most years I only run the AC about 20 days or so. I've run it once this year and we have had a couple of days with temperatures in the high 80's. Living a block from the ocean has it's benifits but the winter can be a different story!

Bob

KC_Jones

SWEI said:

Whole house fan, anyone?

Got one, grew up with one. Love them and would never own a house without one. I just installed my window units on Friday for the first time this year. Until then I was using the fan. At night when it cools off I have a breeze/wind blowing across my bed that is wonderful. I have theorized about the basement idea, but haven't tried it yet. The other advantage of the whole house fan is getting that blanket of hot out of the attic. I have taken a thermometer into the attic and it's nothing to see 20° drop in attic temps when the fan is turned on. Of course you need enough openings to allow the fan to push air out of the attic as well. As Bob said the real trick is opening the right windows to move air through all rooms and not suck from the hot side of the house.

SWEI

Newer whole house fan designs are quite a bit better than what some of us grew up with. Look at Airscape, Invisco, and Tamarack and you see designs which are more efficient, much quieter and include features like motorized, insulated doors.

Consider adding engineered air inlets in the basement or low on the ground floor. Marry a motorized damper with a furnace filter and replicate as needed. You now have the option to automate the entire system. Removable insulated baffles (or quilted covers with magnets) can be useful for the dead of winter.

Charlie from wmass

Just had to change a belt on one of the old style house fans. I will look into the ones you mentioned to see if the customer ( not marcl) would want to upgrade their unit.