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    help with updating heating system (29 Posts)

  • boston_recording boston_recording @ 11:03 AM
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    help with updating heating system

    Folks, I’m trying to address problems with my home heating system and need some help. I’m a homeowner and have little technical knowledge about these matters, so please excuse my ignorance and poor use of terminology.

    These are my issues:

    • The burner is LOUD. This is actually a big deal for me since I have a sound studio here and use the basement as a satellite recording space. This is my bottom-line problem; I have to improve it.
    • My oil consumption is high. I keep the house in the mid- to upper-60s and still burn a lot. (Spent $4600 in 2012, including hot water.) I live alone, so don’t use all that much hot water.
    • The boiler appears to be oversized. I came up with an approximate heating load using web-based calculators, and it was closer to 70k.

    Here’s my current setup:

    • small masonry cape (~1500 ft2); no insulation but tight storms
    • attached wood frame barn (~700 ft2); heavily insulated; no doors or windows; electronic equipment in one of two rooms generates considerable heat so there’s very little impact of the barn on the heating load
    • two-zone oil-fired FHW system for both house and barn; barn on same zone as unused basement convectors; may have been a steam system originally
    • cast-iron HW convectors in house (circa 1948); new baseboards in barn
    • 140,000 BTU/hr Weil McLain with domestic hot water coil; 4 yrs old; good condition; recently serviced as part of annual contract
    • there MAY be gas service to the house (that is, there’s a pipe stub but National Grid has no record of it; it’s possible that the line is intact but they’re noncommittal)
    • the boiler is vented through the chimney, which was also cleaned this year and is in good condition

    If I could improve what I have, I’d be happy to keep the current system intact. So my first question is:

    Can I significantly reduce the noise level of my current oil-fired boiler? I haven’t found any basis to think this is possible other than soundproofing the space; I’m looking into this elsewhere. BTW, I also experience higher than desirable noise from the hot water distribution when the system is active; I assume this cannot be easily addressed unless encapsulating the pipes. But is it possible that different type of circulators (or some other change) could reduce the noise of hot water flow?

    If I can’t improve the noise level of the current system, it appears that I need to make a fundamental change. However, I’m baffled when trying to compare the choices. I’ve had a few plumbers in here, also asked around, and have gotten lots of conflicting information. So I’m hoping for some enlightenment here!

    It seems like the basic options are:

    1. Replace the oil burner with a gas burner. This would be the least expensive choice, though I have no idea about whether noise levels would be sufficiently improved with such conversions. I’ve gotten a huge range of opinions about this one, from strongly positive to strongly negative. Some say that the efficiency of an oil burner converted to gas would be far lower than a unit designed for gas in the first place; others say this is a minor issue.
    2. Replace the entire boiler with a high-efficiency (~85%) cast-iron gas unit. This would be more expensive, but seems to be non-controversial; it appears like it would greatly reduce the noise level, provide long-term reliability, and (at least currently) benefit from the favorable cost of fuel. If the costs can be justified, I have a feeling this would generally be a non-controversial choice.
    3. Replace the entire boiler with a high-efficiency (~95%) mod-con gas unit. This would be the most expensive option, MIGHT be the quietest (I’ve gotten mixed feedback about this), and (at least currently) more than any other solution benefit from the favorable cost of fuel. I intend to live in this house for ~10 more years, so I’m not concerned about the shorter lifecycles of today’s condensing units. I’ve gotten mixed feedback about the advisability of installing such a system in a home with traditional cast iron convectors, though it’s clear that plenty of people are doing this. I’ve read that outdoor reset makes it possible to run such a system at temperatures consistent with condensing, but it also seems like using oversized convectors might be necessary and I can’t do anything about this.

    I realize that the cost savings of (current) gas operation need to be balanced by the conversion investment (costs of bringing in gas service, venting, oil tank removal, and any cost differential of installation.) My initial estimates suggest that the worst-case scenario is a 5 – 7 year amortization, which is fine with me. I was surprised to learn that National Grid is offering the Burnham Alpine for $1100—less than a traditional cast-iron boiler after all of the rebates are factored in—so that has to be considered. I haven’t seen anywhere near the enthusiasm for the Alpine as for other mod-cons, though.

    So, my second basic question is:

    If it turns out that replacing the current heating system is justified, which is the best way to go in my situation?

    I appreciate any and all feedback, and will be happy to supply whatever additional information would be helpful. Thanks in advance!
  • HomeOwner1 HomeOwner1 @ 12:39 PM
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    We went mod-con combi in similar situation

    We live in New Jersey. We had an almost exact scenario with a similar size place to your total square footage.

    We had a relatively new oil 85% 150,000 BTU oversized boiler with hot water coils built in. It would short cycle during operation and was extremely inefficient in operation We were spending crazy amounts of money on our oil bills. Ours was noisy as well, but was not the motivation for replacing it.

    Our heat loss was calculated to be between 80-90.

    The low end of our budget was a gas gun conversion. We figured it would have maybe saved us about 30 to 40% off our bills given fuel costs and was roughly the cost of the gun and parts times two to do that with labor and parts from quotes.

    In a similar budget option was an 80% new gas boiler.

    The next level up was a 240,000 BTU Mod Con Combi boiler for only slightly more installed than the 80% unit. It does both hot water and heat in one unit. The unit was only slightly more expensive then the cast iron boiler, so it was a no brainer for us. The efficiently on the heat side is around 98% and probably 87% for hot water, if I recall the numbers correctly, with a combined efficiency of 92% as its rating.

    The next level up was a WM mod con with indirect water tanks. Really expensive, was quoted about 3 to 4 times the amount of the combi installed.

    We chose the natural gas Combi unit and love it so far. The unit runs our 3 baths and household just fine. We learned combi boilers are sized on hot water demands, so it is way more than we need on heating. It compensates for efficiency on heating with an outdoor sensor which modulates loop temperatures lower when needed. Also, can run all the way down to 20,000 BTU for heat. Based on current gas bills this year, we expect a 1.5 to two year return on our investment where this unit will have paid for itself in full based on fuel savings. Seems like your home fits our description as well.

    You will see a lot of negative comments on this board against combi units but we love ours. We spoke to a few folks that had our exact unit for a couple years in operation before purchasing to be sure. Our particular unit has some early growing pains back when it was first introduced but they appear to have worked out the glitches since then.

    Chimeny was cheap and easy as well for our unit, just a PVC pipe up the existing chimney stack with a new cap.

    If you buy the same combi boiler as us, make sure you get the outdoor sensor option installed. We run our hot water at 130 degrees and adjusted the outdoor temp curve setting to our particular region's optimum efficiency. It is adjustable based on a formula per region and home.

    Also, given how new your existing unit is, you should ask about reuse for your existing pumps, backflow, zone valves, thermostat controls, etc.... Can save you some money.
  • boston_recording boston_recording @ 11:55 PM
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    thanks!

    I appreciate the reply.

    Can I assume you're talking about the Navien product? It's remarkable that there would be such a comparison in the cost of similar technologies with the difference being indirect hot water. Did you get a sense of why this is the case?

    How does the system do when hot water needs to be suppled to multiple locations simultaneously?
  • HomeOwner1 HomeOwner1 @ 9:22 AM
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    Yes, it was a Navien

    From what I understand they are still working on brand recognition and reputation breaking into the US market to command a higher price like the others. It is only slightly more expensive then a 80% cast iron boiler.

    I notice no difference in time to get hot water between my old boiler with coils and this on-demand unit. Water heats up quick and keeps up with our demands in our home with a full family. We have multiple people showering and using hot water. Works just fine. An average person would never know we had an on-demand hot water unit unless they were told.

    It puts out roughly 5 gallons per minute in the winter on the coldest days and about double that during warmer times. That translates to about two or three people taking showers at the same time in the winter in our home. For on-demand hot water heaters, you lose pressure when you have everything on in the house all at once. For the normal tank hot water heaters you just eventually lose hot water.
  • Zman Zman @ 6:33 PM
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    Name that actor...

    "If you want to believe in something,

    then believe in it."

    "Just because something isn't true,

    that's no reason you can't believe it."

    Maybe my favorite movie, I find the words soothing when engaged in these kind of discussions.
  • Robert O'Brien Robert O'Brien @ 9:29 AM
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    Does make you think,doesn't it?

    "It's remarkable that there would be such a comparison in the cost of similar technologies with the difference being indirect hot water."
  • SWEI SWEI @ 11:23 AM
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    Similar technologies

    not really.
  • boston_recording boston_recording @ 12:43 PM
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    similar from a distance

    I was just referring to the fact that they're both mod-cons. I'd love to hear more about what makes them different!
  • Robert O'Brien Robert O'Brien @ 1:47 PM
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    Different

    Navien is a tankless water heater with a flat plate HX for space heating,that's a pretty big difference! I have limited experience with Navien,I've only seen two and wasn't impressed. If something is almost half the cost of it's competitors,what does that say?
  • boston_recording boston_recording @ 9:30 PM
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    opinions about the Alpine?

    Locally, National Grid offers incentives on the Burnham line when converting to gas. They're pushing the Alpine hard, to the point that the equipment is cheaper than a comparable cast iron unit. (The 105k BTU version would only set me back $1100.) SInce I won't have to worry about longevity, this seems like an attractive offer. Is that a shortsighted perspective?
  • gennady gennady @ 10:26 PM
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    navien

    i guess homeowner just works for navien and working on brand recognition. Burnham alpine has gianoni heat exchanger and it is heat exchanger of the past. Weil Mclain has good boiler, just avoid their gv90+, Go with indirect water heater. it will allow you to size boiler for heating load and satisfy your domestic hot water requirements.
    Gennady Tsakh

    Absolute Mechanical Co. Inc.
    www.AbsoluteMechanicalCoInc.com
  • boston_recording boston_recording @ 10:15 AM
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    Alpine vs. cast iron?

    Thanks for the feedback. I've looked at other mod-cons, and it appears that these options would cost at least $2k more (absent the National Grid incentives). Would other costs over a ten-year period make the WM or another mod-con worth the additional investment? I'm assuming annual maintenance costs will be roughly equivalent, but perhaps not.

    If the choice comes down to Alpine vs. cast iron, which would you suggest?
  • HomeOwner1 HomeOwner1 @ 1:30 PM
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    Make your own decision....

    There are a lot of folks that are anti-Navien here. I own one, it works just fine.

    They had a bad start-up and eliminated some of their earlier copper heat exchanger models. Now they just sell the stainless model.

    We live in the same town as their support center, so that helped since they are local to us.

    When we were researching and making our decisions, there were so many people telling us that combi units could not possibly ever meet our needs or ever work correctly.

    Then we had the camp of folks that were insistent on staying cast iron and to never go with a condensing boiler since they last 30 years.

    Ours works fine. It will do the job if installed correctly and sized correctly. Just get someone that knows how to install it correctly.

    Opinions are very polarized.
  • gennady gennady @ 7:59 PM
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    Boiler

    You will live with new boiler for many years. Make a wise choice and do not get sold on price and rebates. I m also a huge Viessmann fan. This is only boiler I offer to my customers. I have no call backs and have no boiler service to run. Set it and forget it. As per mod con versus cast iron, the part mod of the name makes all the difference, modulation of firing rate is the key factor in the savings, and CI boilers do not have this feature. I did modify commercial CI boilers to get load matching by imitating modulation, but it comes at a cost and if you do work from the scratch, go mod con, no question ask.
    Gennady Tsakh

    Absolute Mechanical Co. Inc.
    www.AbsoluteMechanicalCoInc.com
    This post was edited by an admin on July 31, 2013 8:24 PM.
  • Zman Zman @ 2:45 PM
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    Polarized?

    I am thinking there is a consensus of folks that don't think the Navian is a solid product.
    There are also quit a few folks that think combi units are an unacceptable compromise in many applications. Bear in mind these are pros that actually know how to calculate this stuff. Educated opinions not "gee mine works really well".
    Homeowner1's persistance makes me tend to agree with Gennady that  this is the work of a Navian employee.
    Carl
  • Comics Comics @ 4:42 PM
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    I have had it for 2 years ago

    My brother-in-law installed. It runs good. He has a business and installs many of them. He would not have put it in my home if it was not good. I help him on the side with some installations for the piping work and to carry out the heavy stuff.

    He does a lot of Weil Mclain as well.

    Mostly forced air work is out there now except for in the city. It is just too expensive to install on new construction nowadays.
  • Chris Chris @ 5:28 PM
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    Limitations

    The Navien has its limitations, you cannot get caught up in it's btu/hr rating. The on board pump will only move approx 5gpm across it's heat exchanger. So if you have a traditional baseboard system running on a 20 degree delta-t that's only 50,000 btu/hr for heating. You can't get no more then that unless you increase the delta-t.

    The first version had their issues and many of them. I also know guys that install the CH Series and have the tech line on speed dial.

    As for the Alpine, now's the time to get it. Burnham is offering free 10 year parts and labor warranties until Sept so make your decision soon.

    I'm biased so my choice is Viessmann. A Vitodens 100 is very attractively priced and the best HX on the market hands down...
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • Robert O'Brien Robert O'Brien @ 7:00 PM
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    I'm not biased

    Make the same $ installing any of these,but I would put a Viessmann or Triangle Tube in my own house.
  • R Mannino R Mannino @ 7:16 PM
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    The Real Question

    Mr. O'Brien is WHY??? you'd only install those mod cons in your own home?
  • Robert O'Brien Robert O'Brien @ 7:58 PM
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    Mr. Mannino

    What would you install if a natural gas line suddenly appeared alongside your house?
  • R Mannino R Mannino @ 8:28 PM
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    Probably

    A Vitodens 100-26, but a Triangle Tube Solo 60 might be good too!
  • Robert O'Brien Robert O'Brien @ 8:00 PM
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    Worked on many different types

    But I feel those two have the best combination of robust ,proven HX,controls and design. Although the new NTI is quite interesting...
  • boston_recording boston_recording @ 10:09 PM
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    fair enough, but...

    are those products worth spending at least an additional $2k?
  • Chris Chris @ 10:12 PM
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    But A B2HA19

    With the low end 12,000 might just be the winner.
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • Robert O'Brien Robert O'Brien @ 5:50 AM
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    That much difference?

    It shouldn't be that great a difference,at least it isn't on LI
  • boston_recording boston_recording @ 9:24 AM
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    the difference is the incentive program

    The cost of the Alpine through National Grid is $1100 when converting to gas... tax included... less than the cast iron options...
  • Robert O'Brien Robert O'Brien @ 9:48 AM
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    Incentive

    The EE rebate is for any mod/con not just Alpine.
  • boston_recording boston_recording @ 5:07 PM
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    didn't realize that

    Thanks. That's the most useful information I've heard so far!
  • NYplumber NYplumber @ 4:11 AM
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    Navien

    Stay clear of the Navien, Quietside and all those handyman grade heating units. Worked on one recently with all types of issues. Partly due to being misapplied, however they aren't service friendly units and surely dont have longevity built into the design. Viessman, TT and Lochinvar are my choices after servicing many high efficiency boilers. You get what you pay for.
    As for the alpine, make sure your on top of the ph in the boiler or you will get far too familiar with the fine print on the warranty paperwork.
    :NYplumber:
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