Reasons for not selecting the highest efficiency steam boiler?

Mike T., Swampeast MO

Maybe yes, maybe no. Pay CAREFUL attention to Brad White's--the first to this thread--wonderful response. Get the ENTIRE system in top-notch shape (to possibly include re-sizing of the rads if possible/necessary) and if history holds at all true, fuel oil (where widely available) will remain the most cost effective fuel (on a BTU) basis with the Megasteam providing efficiency levels that hithertofore were considered unattainable via residential steam.

If you have any time at all, buy Dan Holohan's (owner of this site) regarding steam. Read, re-read, COMPARE to your existing system and read again. This will give you the ability to <I>rapidly</I> separate the good steam men from the hacks and wannabees.

Mike Kehoe

Selecting a replacement steam boiler

What is the highest efficiency gas steam boiler that I can hope to get to replace my old boiler? Are there valid reasons to go with a boiler that is not the highest efficiency? I have a pretty big house in upstate New York near Lake Ontario, so the heating season is pretty long.

Brad White

Typically

The best steam boilers such as Burnham Megasteam (oil-fired only) the MPO and others fall into the mid-high 80's (85-87%) AFUE for what that is worth. Naturally this depends on how well the boiler is matched to the radiation and how well the radiation is matched to the heat loss.

Of course the aspects of proper venting, insulation of piping, how well your house itself is insulated, how low a pressure you can run and how well you control it, use of TRV vent valves if on one-pipe steam, all play significant roles, especially together.

Installing the best and most efficient steam boiler in a poor match-up will defeat the best number on that yellow energy efficiency tag...

If you burn oil, to me that is the best use of it because you will not be in a condensing mode anyway; you will be running above flue gas dewpoint.

If you are burning gas, so be it. Your efficiencies will tend to be a point or two less than oil.

The rationale of using a less efficient boiler is a matter of your first cost savings amortized over the life cycle cost of the boiler, just like that. You may find that a so-called lower efficiency boiler may be a "better fit" to the system to which it is connected so you may in the end get a better efficiency than a poorly applied 87% AFUE boiler. One has to take all things into consideration.

My $0.02

Brad

Mike Kehoe_3

I'm wondering about efficiency (apart from the obvious reason of wanting to save money) because I'm trying to take advantage of the NY state tax credit for replacing my home heating system. To get the tax credit, the replacement boiler has to be "Energy Star" rated. Do you think that the less efficient boilers would nonetheless qualify for the "Engery Star" rating?

jalcoplumb_7

AFUE

Most gas steam boilers will not qualify for a rebate. Most will not break the 83% AFUE and will not be "Energy Star" rated. Look close at the ratings, some of the boilers have a dual AFUE rating one for steam and one for hot water. Make sure you are looking at the right one. The smaller the boiler the better the AFUE rating is.

If you find a gas fired steam boiler that does make the "Energy Star" rating let me know, I have been looking long and hard.

Mike T., Swampeast MO

The only Energy Star residential steam boiler I've seen is the Burnham Megasteam (oil only at present).

An energy star rating requires efficiency significantly above the norm. Residential steam boilers are extremely mature (and fairly primitive) technology with a small (and shrinking) market. The Megasteam [appears] to be the first nearly complete re-engineering of a residential steam boiler in decades. Burnham deserves high praise for devoting highly-sought R&D dollars to such...

Mike Kehoe_3

That being the case, would it be worthwhile to switch from natural gas to oil, in order to get a Burnham Megasteam?

Tom Hopkins

Peerless

EC series and some of the WB series are EnergyStar rated for Steam,albeit at reduced firing rates.You better hurry for the NYS tax credit,I don't think it's been extended and expires 6/30/07

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

Dave_23

Standing pilot boiler

For my home (WM EG-35) I went with a standing pilot instead of an electronic ignition system. Even though the SP reduces efficiency, it tends to keep the boiler slightly warm and dry during the off season. Since the boiler is in the basement, where humidity is up, the drying effect of the SP is helpful. BTW, this was a recommendation by the steam expert I had install the boiler at which time he disclosed the reduced efficiency tradoff. So...here was one reason for selecting a lower efficiency boiler.

Mike Kehoe_3

NYS tax credit

Thanks for the tip about the 6/30/07 deadline. I have already taken steps to ensure that I get the rebate, assuming that I can actually find an Energy Star rated gas-fired steam boiler, which doesn't look too likely at this point. In case anyone is wondering about the tax credit, the 6/30/07 deadline is the deadline by which you have to incur the expense for which you are going to seek the rebate. However, the actual installation does not have to be complete until the end of the year. For example, in my case, I have already paid my heating specialist $1K as a deposit (in order to recover the max credit, which is $500) on the replacement of my boiler. To summarize, under the tax provision, as long as the cost is incurred before July 2007, installation only need be completed by the end of December 07.

Ed N.Y.C.

Mike

As of 07-28-06 The only steam boilers that qualify are as follows. Peerless EC/ECT-04 1.25 GPH, PeerlessEC/ECT-03 .75 GPH PeerlessEC/ECT-05 1.75 GPH . I'm sure more were added but I haven't got the updated list yet. Hope this helps ED

J.C.A._3

Mike,

If I may put fourth a personal opinion.

Why bother with the "pittance" that the Energystar rebate will give you...when,if you find a PROPERLY sized boiler for your application..and have the near boiler piping done right(including the VENTING!)you will cut your fuel bills by WAY more than the cost of the switch to oil?

Use the header at the top of the page and "Find a Professional". There are some great steam guys out there....but there are also hacks. Get Dan's book..."So, We got Steam Heat"..and learn what you can.

Become a better steam owner and learn WHY....then make sure the contractor also understands.

If you're considering this as a money saver,that deep..why not consider a switch to hot water?(Oh MY...I may have pissed off the steam Gods...but I am unwilling to apologize. JCA)

Mod/cons with all those lovely radiators available to be saved...will pay you back in spades!You've got time...check out the options.

It will NEVER be less expensive "upfront", but the savings will pay you back far faster..as the price of fuel escalates.
I don't know about you, but I've come to the conclusion that the fuel entities have finally figured it out...and they're going to ride the tide until something cheaper arrives...and the fuel choice ain't gonna make that much of a difference! Chris

Christian Egli_2

Oh what a model of efficiency the tax code is

Dirty little secrets about combustion temperatures tell us not much at all happens beyond the universal 80% efficiency. Bang. Play with dampers and pilot lights for true savings - yes - but I find them a hard swallow as they are added onto efficiency numbers. Oh well, labels are not worth the glue they come with. Is there anyone here who actually believes the EPA estimated gas mileage on the sticky stickers they glue inside our new cars? Not me, not for one second.

Playing with these numbers is a gooey subject and I have no advice to offer on what taxable issues are involved in NY and I wish the government did not push us into twisted decisions based on tax code language. Aren't we all glad we got big promises out of the telephone back tax refund? The next big one will be the HDTV rabbit ear conversion refund. You mean you didn't save the receipt for your 35 year old TV set? Oh dear. Meanwhile, I still hope you'll meet the qualifications for getting your very own $500.00 back.

What's up with creepy numbers on steam boilers, hot water boilers and warm air furnaces?

First off, condensing features are routinely achieved in hot water boilers and even more so in warm air furnaces. While these low temperature machines yield exactly not much in increased appliance efficiency they do deliver some amount of extra bonus heat that gets squeezed from the smoke coming off our gas fires. It's real money, it's nothing to spit at but it isn't either a whopping return on your gas purchases.

Only the natural gas fired appliances get to fog up enough humidity to make condensing a worthwhile effort. LPG numbers are not so impressive and oil is rarely a fruitful candidate for the bonus percentages that come from low temperature flue gas condensation. Plus, system wide now, when you go low temperature you loose lots of thermal efficiency which affects your home heating operation in many weird ways. (I am hinting here of course at why warm air furnaces don't operate with the thermal efficiency of a steam radiator system; hot water systems fall in between)

To go off a physics tangent, when we play with 1 kWh of power in either fuel, we are playing with, in the case of oil, 0.10 liters of water in the form of humidity in the flue gasses. Play with LPG, and the available water goes up to 0.12 liter. For natural gas, we allow ourselves a whole shot of 0.16 liter. It is not ever possible to de-evaporate all that moisture. Practical sales brochure tout natural gas condensation but usually not that of oil burners and so we can guess that under most optimal conditions we'll be able to render about 0.05 liters of condensed water for every 1 kWh of fire consumed.

In numbers, that's about 110 BTU for the rendered condensate off of 3414 BTU for the 1 kWh, a bonus return on your utility money of about 3% when all is condensable. If we guess that we burned about $2,000.00 worth of gas to survive the winter, the bonus kick back condensation yields (at 3%) $60.00. It's real money but it is not necessarily significant.

I don't mind eating $60.00 worth of doughnuts though. How else can we improve all this? Well, the damper, the pilot, the increased system wide thermal efficiency, and of course, the lowering of the indoor thermostat. This last action leads to a treasure trove of doughnuts.

Back to boilers and furnaces.

In warm air furnaces the condensing feature does a nice job - if not a vital job - of recouping the lost thermal efficiency of the generally low temperature warm air floating through the ductwork. Hot water boilers achieve less of the condensing bonus, but they also operate with less to loose on the system wide efficiency. If not a wash, at best a small return on your heating dollars. In both cases there is value in recuperating the heat of condensation.

Hotter steam comes with a higher system wide thermal efficiency and so there has always been less of an urge to scrape the condensation bonus. That's why it does not significantly matter to steam boilers to be of the flue gas condensing type, plus, it's not a natural thing for steam boilers to be condensing in the first place... However, big power plants do all that sort of thing and it's (just) a matter of scale to get residential steam in the same boat. Thank you Burnham for the new Megasteam.

Back to cashing in on the tax credit and getting more work done.

Maybe there is some qualifying equipment you can buy to produce your domestic hot water independently from the boiler - steam boilers don't exactly shine at this task during all of the summer. Work the job all together to get cost efficient and energy efficient.

Perhaps also considering installing a new combined AC and heat pump will do very nicely for shoulder season and redundancy. Keep the winter steam for effective heat. Again, I've stretched out the job a bit more than what the $500 would cover, but there are always lots of opportunities to work on.