High Effic Steam? Tax Rebates?
I hope Master Plumber and others on this forum will offer replies to these questions regarding an oil to gas conversion for a steam heating system. National Grid current offers a $500 rebate in some zip codes for what it describes as high-efficiency steam boilers “with electronic ignition and 82%+ AFUE (Annual Fuel Utilization Efficiency) 
I hope Master Plumber and others on this forum will offer replies to these questions regarding an oil to gas conversion for a steam heating system.
National Grid current offers a $500 rebate in some zip codes for what it describes as high-efficiency steam boilers “with electronic ignition and 82%+ AFUE (Annual Fuel Utilization
Efficiency)†rating. Here’s the link:
https://www.powerofaction.com/mnyrgnaturalgasheating/
1) What models of steam boilers have electronic ignition and an 82%+ AFUE?
2) However, am I correct that IRS residential energy tax credits are available only for “a natural gas, propane, or oil hot water boiler or oil furnace placed in service after February 17, 2009, [with an] annual fuel utilization efficiency rate [of at least] 90?â€
Quotation above taken from Instructions for Line 3B of IRS Form 5695, Residential Energy Credits
3) Do any steam boilers/furnaces achieve an AFUE rating of at least 90%? If so, what models?
4) Or is it necessary to upgrade from a steam system to a hot water heating system to use a furnance with an AFUE rating of at least 90%?
5) To upgrade from a steam to a hot water system, must all the heating pipes and radiators be replaced? Or can the existing steam pipes and or radiators work with a hot water heating system?
6) If all the existing pipes and radiators must be replaced to upgrade from a steam to a hot water system, is there any way to roughly estimate that cost by square footage of the residence, or number of rooms, or number of existing radiators?
7) As with so many of these calculations, the question seems to come down to upfront costs vs long-term savings. Is there anyway to estimate the comparative costs of a) a new steam boiler of 82% AFUE used with existing pipes and radiators vs. b) a new hot water boiler of 90% AFUE with new pipes and radiators? I recognize that the latter would provide the greater savings in the long term.
As always, I appreciate the feedback from the members of this forum that helps so many Brownstoners.
OP here:
I think we all consider both time and money when deciding what we can upgrade in our homes. Or to put it another way, I value of a window of opportunity to do certain work, as well as the value of ROI.
So first, Denton, as someone who has admired your renovation, as chronicled on this site, I agree that a gut rehab presented an invaluable opportunity to convert from steam to hydronic water system, good for the next several decades.
And that time frame may be appropriate. CMU, I agree it’s worth considering ROI (which is why I asked in the first place). But using MP’s rough estimate of $40,000 above, and your calculation of $500 savings per year, that gives you a break even period of… 80 years?
Tough to justify except as part of a gut rehab, I think.
My thanks to both of you for further input.
Now, if only I had the resources (and patient neighbors) to pile drive a geothermal system down into my postage-stamp backyard:)
96%, CMU, not 94%
ROI is not foolish. Unless you can afford the cost of conversion, it’s the only way to choose. A steam system has the advantage of simplicity:(no pumps, fewer controls, and is 82% effic. instead of 94% for the absolute best modulating boiler. Besides the conversion cost noted above, there’s the venting costs, and the install. And one often forgets the 500w pump that uses electricity in a hydronic system.
Unlike MP, I have no issues with claiming how much you’d save (theoretically)…steam:82% tops hydronic: 94%; steam also loses more vagrant heat, so say 75% vs 94%: you’d save about $500/year tops for a 4-story brownstone. Less if it’s well insulated. So you do the math on ROI.
It does not matter much if energy goes up or down in the future, since we’re comparing apples to apples, or gas usage to gas usage.
roebling, yes, as part of a gut reno I did exactly what you and mp have discussed, replace an ancient steam system with a modern hydronic water system with indirect hot water heating tank, and it cost just what MP said it would. Except I didn’t have any additional costs for plaster repair since it was a gut.
I’ve already got my NG rebate check.
I think ROI is foolish in this cuz no one knows what energy will cost a decade from now but if they did they can make some money playing it. However imho there is quite a chance it will cost more than less, shale cracking notwithstanding.
If you disagree, then don’t sweat it!
MP, good to know about the efficiency of the Burnham models.
I wonder if anyone else reading this thread has upgraded an aging steam boiler to a newer and more efficient model and would share their experiences.
Yes. 82.2% on most residential Burnham models.
Master Plumber, even on a busy day, you offer input that is invaluable, clear, and much appreciated.
It’s clear that a homeowner considering a switch from steam heat to hot water heat should probably replace all the piping, and that the cost of doing so would be considerable.
I’m not surprised such conversions rarely happen, in your experience — even if it means a homeowner needs to forgo the 90-95% efficient hot water boilers and forgo the tax credit.
Still, I’m encouraged to read that several manufacturers of steam boilers offer the electronic ignition system required by National Grid for their rebate program.
And am I correct that the new steam boilers from the manufacturers you’ve cited achieve at least, say, 80% efficiency?
Very busy today, but will try to answer your questions:
1. Burnham, Weil-McLain, Peerless and others offer their steam boilers with either electronic or standing pilot ignition systems.
2. Yes
3. No
4. Yes
5. In most cases, the steam radiators can be converted and tested at a cost similar to that of buying new radiators that can be properly sized and match decor. Some pipes can usually be reused, but there is little point in installing new pipes around 80+ year old pipes. Replacing the whole system: boiler, pipes and radiators is the way to do this right to realize desired efficiency and return on investment.
6. Yes, but I’ll tell you nearly every young and eager new homeowner (not assuming you’re in any particular category here) that I encounter enquires about this conversion and it rarely ever happens. For a complete conversion for a home of modest size, start thinking north of $40,000. Then consider what it’s going to take to patch and finish the walls, floors and ceilings opened for the new pipes and removal of the old.
7. There are too many variables to accurately make that call, so it’s a professional decision I’ve made never to quote fuel savings claims to potential clients. Instead, I ask clients to review the literature of the equipment I propose and use the figures provided.
There are also many online resources to help calculate ROI. It’s an installer’s job to arrange and pipe the equipment responsibly to realize the published efficiency ratings as closely as possible. A “90% efficient” boiler installed poorly can and will burn more of your fuel dollars than your old steam boiler quite easily.
That said, in 2010, you should be looking at boilers with 95% ratings instead of 90%.
MP
http://www.GatewayPlumbing.com