Attempt to size new boiler with insulating pipes?

Hibernation_Heating

Sizing replacement boiler for a rotted WM 78. I busted out the Lost Art... bible and , after getting delightfully lost in it for an hour or so, started adding up radiators and what not. I am pretty confident in the calculations of radiators. My hopes were to use a megasteam. My numbers put me just out of reach of the largest “629”. However, if it is true that uninsulated pipes lose 5X as much heat, then insulating the mains will put me right in my bracket. I feel lucky to get back into this house now for my own business. House is 1750’s. 2 pipe, lever (pack less?) valves on radiators and I spotted what appears to be a Richardson valve in the basement
N E 1 have any comments on this from the real world?
Ps. Please give me the answer I want to hear:)

Steamhead

What are your numbers?

Were any radiators removed from this system? If so, you may need to use a higher pickup factor.

Pics of the system would help- especially the Vapor hardware.

Jamie Hall

Do give us the numbers. The pickup factor is built into the boiler EDR, but if they are close you may well be just fine -- particularly if you actually run it as a vapour system. But -- plan on insulating those pipes!

ChrisJ

Why not start with calculating the EDR of the piping instead of assuming 33% is needed?

Hibernation_Heating

My radiation is wanting 161k. The radiators are supplies to the top, returns at the bottom with what appears to be just pipe elbows. No traps anywhere. There are two rooms with no radiation. The customers take a great interest in their house and from all evidence there was never heat in these rooms. Big fireplace was obviously used for cooking purposes in this area. No capped pipes.

Hibernation_Heating

Here’s this little guy

Jamie Hall

161 K is the BTU from the radiation? That give me an EDR of about 670? If it's oil the WM 380 is a little too big, but probably can be downfired. In gas the EGH 385 would probably be about right.

However.

There are a number of other good makes -- and far more important than the make of the boiler is the skill and dedication of the installer.

You have a vapour system. There may be orifices in those inlet valves -- or they may be internally calibrated -- or those innocent looking return elbows may have special gizmos in them. Either way, it is absolutely essential that the you do the venting right -- there was a recent thread on Richardson systems; the only vents are on the dry returns just before they drop to the boiler -- and that you keep the pressure down. You must use a vapourstat, and it must be set to cutout at 6 to 8 ounces. Never more than that.

ChrisJ

The MST629 Megasteam is rated 201,000 btu/h before the "piping and pickup factor".

You have a load of 161,000 btu/h not including piping losses.

Do you think those pipes will dissipate 40,000 btu/h? Doesn't seem very likely to me, even uninsulated.

You'll have a 20% pickup factor which is double what I have in my own house. If it was me, I'd go for it. My simple single pipe system does fine with a 10% pickup.



The other option you have is two smaller Megasteams that can run together and one can shut down on pressure. If you want to go by the book and have some extra capacity, perhaps a MST513 and a MST288, the MST288 shutting down at a few ounces.

Personally, I think the MST629 with well insulated piping and a properly working system will be amazing. The "properly working system" is key here.

PMJ

Too small and you are screwed, too big and you are banging off the high end of your pressure based control too early before the tstat is satisfied. Lots of fretting over the "perfect" size when actually no such thing exists. The demand changes by several multiples but any fixed fire boiler has only one speed. The one big enough to heat on design day is surely much too big on a mild day.

All it takes to eliminate all this worry over size is a shift in thinking away from pressure based control. Ecosteam did this. Then some extra boiler has no downside and the decision is not such a big deal.

My recommendation - get a little extra and upgrade the control.

New England SteamWorks

The MegaSteam is definitely the boiler you want. And if your numbers are correct and you insulate your piping, a 629 will be just fine.

Hibernation_Heating

Great forum. I appreciate the info. Anyone know who actually manufactures the Ecosteam?

PMJ

@Hibernation_Heating ,

The Ecosteam is no longer manufactured. Apparently the market did not embrace it as hoped. On one hand I am quite surprised as the theory behind it is spot on and the performance improvement dramatic as I believe @ChrisJ will attest. On the other hand I am not surprised as there is pretty stiff resistance here to changes of any kind in the control methods first introduced in the 1950's for steam systems designed for continuous coal fires and being replaced by gas and oil with intermittent fire. If you are interested there are some pretty simple ways to achieve some pretty dramatic improvements to the temperature swings associated with the conventional pressure based controls.

I have attached the pages of the Ecosteam manual that details the operation of the heating cycle. The approach is based on some very sound thinking. Reading it I'm sure you will see quickly why such a control tames a big boiler quite easily by simply not letting it run so much. It really isn't clear to me why this basically simple concept hasn't been used more widely to eliminate the seemingly endless worry over boiler size and pressure.

Jamie Hall

That's one of the problems with a free market. When something works well enough -- as a properly installed and adjusted "stone age" control system does -- and is dang near bullet proof and is cheap, it's really hard to sell something which may well be better, granted -- but costs a good deal more, is proprietary, and harder for the average person to operate, never mind fix.

As in my usual example. Cars. I'll happily grant my wife's 2017 car with the computer controls runs better and is more reliable than my 1970 truck. Or my 1951 tractor. However, if something dos go wrong with my wife's car, it's a flatbed and a tow to the dealer and a very large bill. I can't get some of the parts (I'm not a dealer) to fix it, even if I wanted to. The truck? There isn't much that can go wrong with it that I can't fix with a box of tools and an afternoon under a shade tree. We have the 2017 technology, one needs to remember, not because of consumer demand, but because California and the EPA mandated it.

PMJ

But quite obviously residential steam heat does not work well enough. It is plainly dying. The reasons it is dying are not all because of the government. I had one of the "works well enough" systems 25 years ago and as an engineer it was clear that much could be done much better and quite simply. It was obvious to me quickly that barely measurable pressure was all that was required to get the heating done - even on design day. So when I found this site I was wondering why everyone was talking about steam pressure in PSI? It does not take a control anywhere near as sophisticated as Ecosteam to make a dramatic improvement and run without pressure. It does not take a lot of money or any proprietary software or even a computer either. Steam did , however, need some interest from those in the industry if it was to have stayed current and alive. Few here have actually experienced first hand the improvement that is possible with these systems.

Heaven help us if we ever get to the place where technology improves only because some government required it.

BobC

In 1968 a buddy and I bought a 1951 Buick for $100, the body and the interior was in very good shape and it seemed to run fine. problem was there was a sporadic electrical problem.

We were at Ft Benning at the time and permanent CQ's at a infantry school support section. We went to the post library and spent time with a Chiltons manual and decided to replace the wiring harness. It took us about a month but we built the new harness using army wire and got that old Buick running like a champ.

Top work on the 6 cylinder engine you crawled over the fender and stood inside the engine compartment ( I was a bit more svelte back then) All you had to deal with was a distributor, spark plugs and a carburetor so any service could easily be done in a short period of time..

We both left that post in late 69 and sol;d that car for $250, it still ran beautifully. There is a lot to be said for keeping things simple.

ChrisJ

Sigh.....

If I had to choose between a cheap PLC and a Vaporstat for reliability, the vaporstat would be in the trash.


How many failed vaporstats have we seen on here?

ChrisJ

Yep....

Jamie Hall

Perhaps I should remind people on the vapourstat -- the reliable mercury vapourstat, which would last essentially forever (it even has protection against overpressure) was forced off the market because some government bureaucrat decided that the mercury switch was a terrible hazard to the life and precious bodily fluids of the general public...

Wrong argument, good buddies.

PMJ

Jamie, I have one of those - and a bimetal strip pilot safety both still operational. But I also have a control that keeps the max pressure so low that the vaporstat is useless except as a safety device. My argument is that the old stuff by itself will not produce a result the public even wants - obviously. Operating the way I do there would be many less systems ripped out each year around me.

ChrisJ

> @PMJ said:
> Jamie, I have one of those - and a bimetal strip pilot safety both still operational. But I also have a control that keeps the max pressure so low that the vaporstat is useless except as a safety device. My argument is that the old stuff by itself will not produce a result the public even wants - obviously. Operating the way I do there would be many less systems ripped out each year around me.

@PMJ since most on here don't know, how would you rate the reliability of a typical PLC?

PMJ

> @ChrisJ said:
> > @PMJ said:
> > Jamie, I have one of those - and a bimetal strip pilot safety both still operational. But I also have a control that keeps the max pressure so low that the vaporstat is useless except as a safety device. My argument is that the old stuff by itself will not produce a result the public even wants - obviously. Operating the way I do there would be many less systems ripped out each year around me.
>
> @PMJ since most on here don't know, how would you rate the reliability of a typical PLC?

@ChrisJ ,

PLC reliability is extremely high. I run units from several different manufacturers at work. At home I run the Teco like you have in the Ecosteam. Not a blip so far. The thing is so inexpensive even if it failed the low annual cost is well worth what it provides.

ChrisJ

I think the issue is people here seem to think a plc is like a PC running windows XP.

It's not.


That said....we've run off course.