advice on new heating system, DHW & gas supply relocation

Reply

  #1  
Old 04-28-13, 08:47 AM
C
Member
Thread Starter
Join Date: Apr 2013
Location: USA
Posts: 14
Received 0 Votes on 0 Posts
advice on new heating system, DHW & gas supply relocation

I recently purchased a 1750 sf 1950s raised ranch that's currently being heated by its original, oil American Standard boiler that's also supplying my DHW. We have recessed cast iron rads on the main living floor, with cast iron baseboards in the basement. Considering oil prices being what they are, we're very much interested in replacing the system that's currently operating at around 60% efficiency...which is probably being generous.

I have been shopping around for the best replacement setup for our needs, which I should outline now; we're a young couple that have intentions of having children and possibly expanding the home down the line. The 6 gallon tank inside our boiler is barely supplying enough hot water (shocker) to our 2.5 baths. We have not even attempted heavy demand; 2.5 baths + dishwasher + clothes washer would be impossible to run within a few hours of one another. Being that it's juts the 2 of us now and we're already running out of water after consecutive showers, we're hoping to eliminate the limited supply of hot water. The original, single-paned slider windows are still throughout the house, which will also be replaced eventually, but not before the boiler installation. Insulation throughout the house is average at best. The existing boiler is tied into a fireplace chimney in our basement that keeps us from utilizing the area in front of the fireplace (the oil boiler sounds like a jet when it kicks on), so we are also intending on installing the new boiler elsewhere in the basement, in all likelihood direct vented. When I purchased the home, there already was a 3/4" gas line piped to where a dryer would go and where we were thinking about relocated the new system to--more on that below.

What does helps us is that I am an architect and pretty handy, so my intentions were to replace the boiler myself to help with my budget, which is a factor. Alsom, to pay for college, I was a plumber's apprentice for a few summers and winters, so I am not really intimidated by the job, but rather making the right decision for my home for the next 30+ years. I have generated a manual-J for the house in Wrightsoft that is giving me around 67k BTU heat loss, so I am thinking of around an 80k BTU for a replacement. I was planning on a blower-door test, but I already know the house won't fair all that well considering the windows and doors.

We've spec'd Navien combis units on a few buildings we've done in some urban multi-family buildings in northeast NJ which have given us nothing but trouble, but we believe it has a lot to do with shoddy installation. Our plumbers from that job has complained about the difficulty of getting Navien reps to take care of their issues and overall below average customer service. With that being said, I am still open to their product, just with a grain of salt. We have a bit of a slight hard water issue here, so I have been reconsidering my initial desire to use a combi system and have almost totally eliminated anything but a stainless steel heater.

In short, I've come here for advice on a few things and am trying to generate a consensus for my needs:
  1. should I go with mod/con combi unit, a mod/con + indirect, or an direct vent cast iron boiler + indirect DHW? Old time plumbers (I know, I know) are still trying to convicne me that I should go with the cast iron and direct vent it (Burnham ESC4 is intriguing) and never have to worry about the techy problems that seem to be associated with mod/con boilers
  2. what brand should go I with? I have been reading about many of them but can't get a definitive answer on which is most reliable, efficient, etc.
  3. understanding that the 70'+ run from the meter (see attached) of 3/4" pipe to the location of where I'm putting the unit is probably not going to provide the necessary MBH, I am wondering if I can run a separate 1" line from the meter parallel to the existing and supply the new boiler/combi and also still utilize the 3/4 line to supply my dryer and my eventual gas range. I realize I could replace the whole line with 1-1/4" and it would supply everything with one line, but the 1-1/4" CSST is super expensive and I was hoping I could get away with the 1"

I appreciate any assistance in advance.
 
Attached Images  
Sponsored Links
  #2  
Old 04-28-13, 09:23 AM
D
Member
Join Date: Aug 2009
Location: USA
Posts: 4,947
Received 0 Votes on 0 Posts
Stay away form units with a tankless coils. It is the worst way to make hot water. Go for an indirect unit. I can't tell you one way or another for mod/con vs cast iron. My recent upgrade was to a Burnham ES2. I didn't think the increased cost of maintenance was going to be worth the savings in fuel.

Have you calculated the output of your radiators? This is really going to help you program the outdoor reset of whichever boiler you buy. You can also help you determine if a mod/con will run at it's peak efficiency during the coldest months. The more radiation you have, the lower the water temps can be.

Another point of concern is that old boiler. It may be insulated with asbestos. So DIY removal may be problematic.
 
  #3  
Old 04-28-13, 11:17 AM
G
Member
Join Date: Oct 2008
Location: USA
Posts: 2,970
Received 11 Votes on 11 Posts
We have a bit of a slight hard water issue here, so I have been reconsidering my initial desire to use a combi system and have almost totally eliminated anything but a stainless steel heater.
Hard water doesn't necessarily mean you have to use a stainless steel heat exchanger. How hard is your water? If there are any appreciable chlorides in your water, stainless should NOT be used.

You can compute the necessary gas piping sizing based on tables in the National Fuel Gas Code, NFPA 54. The answer depends on several factors you haven't listed, so it's best to run your own calculation.

the 1-1/4" CSST is super expensive
Why are you proposing to use CSST pipe instead of Schedule 40 ASTM A-53 black steel pipe? Black pipe is perfectly acceptable for natural gas and is actually way over-designed for pressure and temperature requirements. Black pipe and fittings are readily available at most any hardware store.

It may be insulated with asbestos. So DIY removal may be problematic.
drooplug raises a good point here. If the boiler is from the early- or mid-1950s, I'd bet a $5 to a donut that it is asbestos. The only way to be sure is to pay somebody to test it and give you a written report. If it is asbestos, abatement will add significantly to the cost of removing the old boiler - in which case, it might be cheaper to pay to have the boiler encapsulated and leave it in place.

I have generated a manual-J for the house in Wrightsoft that is giving me around 67k BTU heat loss, so I am thinking of around an 80k BTU for a replacement.
ASHRAE recommends sizing a boiler's DOE rating equal to the Manual J heat loss (which already includes about a 25% design margin).

Regarding hot-water: in gas country, at least here in the Midwest, virtually nobody uses direct or even indirect water heating tied to a boiler. Standard 40-gal stand-alone gas water heaters are most always used. You can buy one for a few hundred bucks and it should last well over 12 years (my last one was 50 years old when I replaced it solely as a precaution).

I don't have any personal experience with wall-hanging combi-units. I believe that none are made in the U.S. so that might explain spotty service availability. From what I know, they are not DIY-friendly - their components often proprietary and crammed into s compact enclosure.

I'm reminded of being told me that in Japan, nobody would even dare to work on their toilet themselves. You call the manufacturer (Toto) and they will send a factory technician, attired in an official, natty Toto uniform. That's not my style. If that's the procedure for repairing a toilet, I can only imagine what it would be for a combi boiler.
 

Last edited by gilmorrie; 04-28-13 at 02:12 PM.
  #4  
Old 04-28-13, 02:00 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 35 Votes on 27 Posts
Honestly, the boiler replacement should be the last item on your list unless you have actually had boiler failure. Improving the energy efficiency of the envelope by insulation and air sealing is paramount. Installing the boiler now, even sized for your current load, will leave you with an oversized boiler after the rest of the work.

Do NOT increase the size of the boiler for an indirect water heater but instead use a timed priority control for that indirect. Properly set up you will never notice it in operation.

Remember that design temperature is rarely achieved more than a few hours to a few days per year and going several years without dropping to design temperature is not uncommon. Anytime your above design temperature your heating system is loafing and is going to be less efficient. There are several ways to "live with" those very few hours/days when your system might not achieve the inside design temperature and you will reap the benefits of a "right-sized" system all those times when the weather is warmer.

I am not a great proponent of replacement windows, unless your current windows are missing glass the payback on replacement windows could easily be measured in several decades. If your windows currently have an architectural component of your overall house's design then going to simple replacement windows could be a huge mistake aesthetically speaking. Replacement windows fit inside the existing window jambs and will lessen the amount of clear window. In addition the replacements will do noting to improve the installation of the original windows such as weight pockets or poor flashing. If you are certain you want to replace windows do so with new construction windows properly installed. The cost will be greater but you will get a better job and some increased savings. Your biggest problem will be finding a contractor willing to do the additional work involved.

What might be a good alternative is custom made storm windows. Good ones will approach the energy efficiency of replacement windows and NOT seriously detract from any architectural amenities of the current windows. Their cost will be somewhat less than replacement windows and significantly less than new work windows.

Air sealing is a place for huge gains in energy efficiency. I strongly urge you to get the blower door test. Sealing of pipe and electrical chases can often save you as much as ten to twenty percent on heating costs. This IS one point in favor of replacing windows if the current windows have really poor or non-existent weatherstripping then the cost of adding/improving the weatherstripping can be deducted from the cost of the new windows.

There are many reasons to consider a low-mass mod/con boiler but just as many reasons to consider a more conventional boiler. I tend towards a high-mass system with lesser automation for a few reasons that I can go into if you want to explore those options.
 
  #5  
Old 04-28-13, 02:51 PM
G
Member
Join Date: Oct 2008
Location: USA
Posts: 2,970
Received 11 Votes on 11 Posts
What might be a good alternative is custom made storm windows.
That's what I have - combination storms and screens over my original 60-year-old, wood-sashed, double-hung windows. When I ran the Slant/Fin heat-loss program, I believe that the predicted thermal performance for new double-glazed windows would have been the same as for my original windows with storms.

Modern double-glazed, double-hung windows are a bit easier to wash on the outside - if they have the tilt-out feature - particularly for those on a second story. I can remove my 2-piece storms from the inside of the house for washing, but for the old original windows, I'd need an extension ladder. Instead, I use a hose-end, house-wash sprayer (with ammonia water) to wash the outside of my original windows on the second story.

We once had a house built. I remember being astonished at the percent of the total cost that was for windows.
 
  #6  
Old 04-28-13, 04:05 PM
D
Member
Join Date: Aug 2009
Location: USA
Posts: 4,947
Received 0 Votes on 0 Posts
Honestly, the boiler replacement should be the last item on your list unless you have actually had boiler failure. Improving the energy efficiency of the envelope by insulation and air sealing is paramount. Installing the boiler now, even sized for your current load, will leave you with an oversized boiler after the rest of the work.
Normally, I would agree 100% with this. However, just by switching from oil to gas is going to save you an enormous amount of money. Buying a unit matched to your 67k heat loss is going to be about 25% larger than needed anyway. You will also be hard pressed to find many units smaller than that. Air sealing and adding insulation will help give you head room for that planned addition in the future. As long as it isn't doubling the size of your home. Never-the-less, you will have the opportunity to make that addition VERY efficient.

People shy away from indirects because of the high up front cost, but they will last a lifetime.
 
  #7  
Old 04-28-13, 05:34 PM
G
Member
Join Date: Oct 2008
Location: USA
Posts: 2,970
Received 11 Votes on 11 Posts
we're a young couple that have intentions of having children and possibly expanding the home down the line.
I've been where you are now at. Maybe you will expand the house and live there the rest of your lives. But probably not.

So spending big bucks for an indirect water heater which may "last a lifetime"? And keep your boiler running all summer? And how should you define the meaningful "lifetime"?

Just install a 40-gal, standalone gas hot water heater. People on the east coast can't fathom that idea. Why? Maybe because they have been wedded to fuel oil for so long? Join gas country.
 
  #8  
Old 04-28-13, 05:45 PM
D
Member
Join Date: Aug 2009
Location: USA
Posts: 4,947
Received 0 Votes on 0 Posts
Just install a 40-gal, standalone gas hot water heater. People on the east coast can't fathom that idea. Why? Maybe because they have been wedded to fuel oil for so long? Join gas country.
Since when is everyone on the east coast using oil? I've been on natural gas my entire life. They sell stand alone water heaters like its toilet paper around here.

What's wrong with running the boiler during the summer to heat the indirect? It's not going to use anymore fuel. You will have faster recovery times than a stand alone. And you will need less vents sticking out of the side of your house. You also won't need to worry about replacing it every ten years. Get stainless or stone lined indirect and you won't need to think about those things.
 
  #9  
Old 04-28-13, 06:04 PM
G
Member
Join Date: Oct 2008
Location: USA
Posts: 2,970
Received 11 Votes on 11 Posts
They sell stand alone water heaters like its toilet paper around here.
Drooplug, why do you suppose that is so?

No, I disagree, running the boiler during the summer to make a little dab of hot water will consume more fuel compared to a stand-alone gas heater. Under that condition, the boiler is hugely oversized, which everybody here condemns. And when major boiler maintenance is best done, in the summer, there is no hot water.

No, not everybody on the east coast uses oil for heating - but a huge, huge percentage of them do, probably a much larger percentage than elsewhere in the U.S., and it may affect the thinking?. If I should ever move from gas country to a place where oil was the preferred or only fuel, I would defer to my brethren in the east for their advice. And I wouldn't dis them.

Get stainless or stone lined indirect and you won't need to think about those things.
"Those things," would include economics?

I've been on natural gas my entire life.
How long is that? My family switched from coal to gas in 1950, and I have used gas continuously ever since.
 

Last edited by gilmorrie; 04-28-13 at 06:29 PM.
  #10  
Old 04-28-13, 07:07 PM
C
Member
Thread Starter
Join Date: Apr 2013
Location: USA
Posts: 14
Received 0 Votes on 0 Posts
very appreciative

I truly do appreciate all of your responses. I do have a few follow-up questions and comments that I would love to continue dialogue on.

Go for an indirect unit. I can't tell you one way or another for mod/con vs cast iron.
So that's at least one vote for indirect by @drooplug, but it appears that @gilmorrie is decidedly against the idea. I have had nothing but tanked, natural gas-fired HWH my whole life; this is the first home that I've had to deal with anything but a natural gas-fired HWH. I am not totally against installing a direct-vent tanked unit, but in our practice, we've seen them be less efficient, so in my case, I am really considering having an indirect tank or possibly a tankless HWH. I've installed dozens of traditional tanked HWH and have been encouraged by others to use the K.I.S.S. method and just stick with a simplified system, but the professional in me feels like I'm being a hypocrite if I go that way.

My recent upgrade was to a Burnham ES2. I didn't think the increased cost of maintenance was going to be worth the savings in fuel.
This is very much a huge hurdle I'm having with myself. Should I pay (possibly overpay) for a "super high efficient" mod/con boiler that, until I properly seal and upgrade my home, probably won't work at it's advertised highest effeciency (or maybe never even operate at those advertised numbers) or go with a traditional cast iron boiler that will be much more efficient than my existing boiler and be using a cheaper fuel.

Have you calculated the output of your radiators? This is really going to help you program the outdoor reset of whichever boiler you buy. You can also help you determine if a mod/con will run at it's peak efficiency during the coldest months. The more radiation you have, the lower the water temps can be.
I have not calculated the output of my radiators; I supposed it'll be one more calc I'll have to look up. I also have had a bit of trouble finding the EDR of my type of radiators. I have a type of radiator I have not seen before (see attached) but I'm sure someone around here could help me locate numbers for.

Hard water doesn't necessarily mean you have to use a stainless steel heat exchanger. How hard is your water? If there are any appreciable chlorides in your water, stainless should NOT be used.
I don't believe the water to be too hard, although I have not had it tested. It is good to know that if there is a chloride problem that I should avoid the stainless.

You can compute the necessary gas piping sizing based on tables in the National Fuel Gas Code, NFPA 54. The answer depends on several factors you haven't listed, so it's best to run your own calculation. Why are you proposing to use CSST pipe instead of Schedule 40 ASTM A-53 black steel pipe?
I don't have a problem doing the calcs, was mostly just wondering if this approach is something that has been field tested and an approach I should consider. As far as using CSST piping, I was hoping to use the flex line to cut down on labor time, although there is a point where price will dictate which I go with. Again, the question was more of the design as opposed to the piping material.

ASHRAE recommends sizing a boiler's DOE rating equal to the Manual J heat loss (which already includes about a 25% design margin).
I am embarrassed to say I was unaware that a Manual J included a 25% margin. We generate the reports, I guess we rely on the guys in the field too much on verifying our calcs being correct.

Honestly, the boiler replacement should be the last item on your list unless you have actually had boiler failure. Improving the energy efficiency of the envelope by insulation and air sealing is paramount. Installing the boiler now, even sized for your current load, will leave you with an oversized boiler after the rest of the work.
I do very much agree with your statement, however the lack of hot water delivery and the extremely high cost of fuel oil is forcing me to put the cart in front of the horse, if you will. I have every intention in improving the envelope and am consciously not oversizing the boiler knowing that the home's heat loss should decrease as the home improvements progress.

I am not a great proponent of replacement windows, unless your current windows are missing glass the payback on replacement windows could easily be measured in several decades. What might be a good alternative is custom made storm windows. Good ones will approach the energy efficiency of replacement windows and NOT seriously detract from any architectural amenities of the current windows.
We have already had talks about improving the envelope in this very way. My company was lucky enough to be invited to Building Science Summer Camp this summer and we learned a great deal of the benefits of well-done storm windows.

There are many reasons to consider a low-mass mod/con boiler but just as many reasons to consider a more conventional boiler. I tend towards a high-mass system with lesser automation for a few reasons that I can go into if you want to explore those options.
I would very much appreciate if you could go into this if you're so kind.

Overall the information you've all presented is very helpful. I am beginning to lean towards a high-efficient, direct-vent, high-mass boiler w/ indirect DHW. I have had no personal background installing a mod/con boiler, but again, am not too intimidated by it. I have had a reasonable amount of time with traditional cast-iron boilers, so am obviously more comfortable with installing this type.

A big desire is to have a direct-vent type boiler, for reasons I mentioned earlier (the fireplace area in the basement). I have looked into Burnham's direct-vent cast boiler and am highly considering it, but am wondering if anyone else has a comparable unit.
 
Attached Images  
  #11  
Old 04-28-13, 07:11 PM
D
Member
Join Date: Aug 2009
Location: USA
Posts: 4,947
Received 0 Votes on 0 Posts
Drooplug, why do you suppose that is so?
Because of the low up front cost and the high percentage of central heating being forced hot air.

No, I disagree, running the boiler during the summer to make a little dab of hot water will consume more fuel compared to a stand-alone gas heater. Under that condition, the boiler is hugely oversized, which everybody here condemns. And when major boiler maintenance is best done, in the summer, there is no hot water.
The boiler is not oversized for heating water. It puts it's btus into the water. I get my best run times heating hot water.

No, not everybody on the east coast uses oil for heating - but a huge, huge percentage of them do, probably a much larger percentage than elsewhere in the U.S., and it may affect the thinking?.
This is the most absurd statement I have ever heard. It's true that most oil users are in the northeast, but that doesn't make the majority of homes heated by oil. We use a lot of natural gas here. That's why it costs so much.
 
  #12  
Old 04-28-13, 07:32 PM
D
Member
Join Date: Aug 2009
Location: USA
Posts: 4,947
Received 0 Votes on 0 Posts
Do you know who manufactured the convectors that you have?

It does seem that me and gilmorie are at odds with the hot water. Using a stand alone unit is not a loser decision. I find that an indirect makes more sense and is a better product as far as recovery time is concerned. I also find it to be a simpler approach. Having a stand alone adds a second combustion appliance that needs to be maintained.

The margin in the manual-j is based on the experiences of people here in the forum. When comparing their calculations to real world measurements, they have found something like a 20%-30% margin.

Some advice on keeping the old windows. Since you expect to have children in the house, you should remove all of the lead paint from them. Windows are a high hazard when it comes to lead paint. When there is lead paint present, it is in these areas where opening and closing the window will generate dust and chips.
 
  #13  
Old 04-28-13, 08:17 PM
C
Member
Thread Starter
Join Date: Apr 2013
Location: USA
Posts: 14
Received 0 Votes on 0 Posts
Do you know who manufactured the convectors that you have?
I have had trouble finding a plate or ID label for the rads. The boiler is an American Standard.

Some advice on keeping the old windows. Since you expect to have children in the house, you should remove all of the lead paint from them. Windows are a high hazard when it comes to lead paint. When there is lead paint present, it is in these areas where opening and closing the window will generate dust and chips.
Excellent advice regarding the lead paint issue.

It appears you're pleased with your Burnham boiler so I am definitely going to look into those. The problem I have, or at least will be creating for myself, is the relocating of the boiler. If I go with he high-mass boiler, I will have to vent with stainless, which is pricey, but I guess it's just part of the budget.
 
  #14  
Old 04-28-13, 09:12 PM
C
c9s
c9s is offline
Member
Join Date: Jan 2007
Posts: 9
Received 0 Votes on 0 Posts
Stand alone HWH are cheap and simple, but not very efficient. With the flue running up the center they have a lot of stand by loss. A side arm water heater only loses about a half degree/hour. A stand alone heater cannot be direct vented either.
 
  #15  
Old 04-29-13, 05:35 AM
T
Member
Join Date: Mar 2013
Location: usa
Posts: 19
Received 0 Votes on 0 Posts
Gas

I live in New England and will say that the main reason anyone is still using oil around here is because gas is not available. Switching to gas, if available, is a no brainer.The price of oil per BTU is just about twice what gas is. The thing also to consider almost all gas companies are offering very substantial rebates when switching to gas. I just installed a Burnham Alpine 80 mod/com boiler whose cost was less then $3000. The rebate was $1500 so the total cost for the boiler was just under $1500. One other thing to think about. It appears that your emitters due to their mass may work well on lower temp water. This is where the newer Mod/Con boilers shine. This is not out of the goodness of the gas cmpany's heart it is madated by the Fed. There is also great rebates on upgrading your home insullation. They do a free energy audit and recommend improvements. Around here it is up to $2000 of which you only pay 25%.

Some things to thow into the mix.

Tom
 
  #16  
Old 04-29-13, 07:13 AM
D
Member
Join Date: Aug 2009
Location: USA
Posts: 4,947
Received 0 Votes on 0 Posts
Try searching "fine tube convector" to try and locate your units or perhaps some that are similar. Then you can get the specs from them to try and figure out your EDR. Maybe someone else here has a better source.

I'm pretty sure there are stand alone water heaters that will direct vent.

Why do you need stainless for a high mass boiler? I know you would need to use stainless if you vented into your chimney, but PVC should be fine for the direct vent. The ESC will say for sure in the manual.

Who is your gas supplier? If you have NJNG, check out the Save Green Project website. I know they were offering a rebate when I got my boiler. There was another rebate I got too. I don't recall if it was from NJNG or not. Their may also be Energy Star rebates through the fed's available as well.
 
  #17  
Old 04-29-13, 10:21 AM
C
Member
Thread Starter
Join Date: Apr 2013
Location: USA
Posts: 14
Received 0 Votes on 0 Posts
Why do you need stainless for a high mass boiler?
I was under the impression that the high mass boiler produced too much heat to use PVC, but I will definitely research before I purchase.

My gas provider is PSEG and I have looked into the rebates by the government as well, although I did not find any that were as generous as $1500 in NJ.
 
  #18  
Old 04-29-13, 11:45 AM
D
Member
Join Date: Aug 2009
Location: USA
Posts: 4,947
Received 0 Votes on 0 Posts
I was under the impression that the high mass boiler produced too much heat to use PVC, but I will definitely research before I purchase.
I checked the Manual for the Burnham ESC and you are right. It will require stainless steel for the exhaust vent.
 
  #19  
Old 04-29-13, 11:58 AM
_
Member
Join Date: Dec 2010
Location: USA
Posts: 332
Received 0 Votes on 0 Posts
i wasn't able to find a single non condensing boiler that would do direct venting and allow for PVC piping.
 
  #20  
Old 04-29-13, 02:15 PM
C
Member
Thread Starter
Join Date: Apr 2013
Location: USA
Posts: 14
Received 0 Votes on 0 Posts
bummer

i wasn't able to find a single non condensing boiler that would do direct venting and allow for PVC piping.
well that stinks. @_Diver did you end up going with a non-condensing boiler or go with a mod/con?
 
  #21  
Old 04-29-13, 08:55 PM
C
Member
Thread Starter
Join Date: Apr 2013
Location: USA
Posts: 14
Received 0 Votes on 0 Posts
square one?

After beginning the day thinking that we should go with a non-mod/con boiler, I am beginning to reverse course. Because we are essentially tied to a direct vent system, because of the aforementioned relocation of the boiler room, I was disappointingly surprised to find that the list for non mod cons boilers that are direct vented is a short list. Furthermore, it seems that any non-mod Con requires stainless steel venting which, by my early investigation is expensive and actually causes the project to a approach the cost of a mod/con.

Am I incorrect in stating that it is A short list finding a relatively small sized boiler this is a non mod/con that is direct vented?

Also , I think I might need a little more education on why sizing a mod cons boiler to the manual J is so critical. I was under the impression that because of its modulation capabilities the boiler could actually operate at a lower capacity, thus making up for any gap between the manual j and expected BTU output. I imagine that the heat loss calculation comes into play much more when sizing a traditional boiler that has not the capability to modulate. Also, how does the outdoor reset module coming to play in all of this?

By all means if someone can enlighten me as to why a smaller mod/con is appropriate (other than obvious budget reasons) I would love to learn. I, by no means, have any intention of oversizing the boiler, but I am running across so many boilers that have a higher BTU output then I need according to my heat loss calculation and am wondering if I would be shooting myself in the foot by overpaying for an oversized mod/con and not getting what I need out of it.

I began preparing a list of boilers for our heat loss needs, but it started to get too long as I had almost every name brand out there to choose from. Almost every brand that I was looking at has at least one boiler that has the modulation capabilities of lowering itself to the heat loss that my home currently has. Again, I am very much appreciative for anyone sharing their personal preferences regarding brand names. Names like Weil-McLain, Peerless and Utica I have seen many times in my experience being a plumber's apprentice, but I don't know what their track record is regarding mod/cons, as the plumber that I worked under didn't install them. Names like TriangleTube, Navien, and Rinnai keep popping up in the mod/con discussion forums, as well as others I never heard from before you like Buderus, Baxi and Lochinvar. As I started to research their available models, I realized that most of them offered combi units, and now I am back at square one wondering if I should--if I am forced into a direct vent modulating unit--go with a combi unit?
 
  #22  
Old 04-29-13, 11:54 PM
F
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,495
Received 35 Votes on 27 Posts
I'm sorry for not posting earlier, I have contracted a severe cold (serves me right going to the medical clinic where there are sick people ) complete with headaches, running nose and general malaise. I'm simply not up to answering in-depth questions at this time.

You have been given lots of good information. My background is with commercial and industrial sized equipment and it often does not "ramp down" to smaller residential systems. One thing where I think you are mistaken is the need for stainless steel flue piping on non-modulating boilers. Gas boilers should be able to use type B insulated vent pipe with few, if any restrictions. B-vent isn't cheap by any means but it doesn't come close to the cost of SS vent.
 
  #23  
Old 04-30-13, 04:08 AM
D
Member
Join Date: Aug 2009
Location: USA
Posts: 4,947
Received 0 Votes on 0 Posts
Gas boilers should be able to use type B insulated vent pipe with few, if any restrictions. B-vent isn't cheap by any means but it doesn't come close to the cost of SS vent.
Furd, I think the reason they spec stainless steel is to deal with condensation in the vent pipe.

Cyrus, keep in mind that a mod/con needs to be installed with a primary/secondary piping arraignment. If you install the boiler yourself, this won't be much of an issue, but if you pay someone, this will add to the labor costs.
 
  #24  
Old 04-30-13, 06:19 AM
C
Member
Thread Starter
Join Date: Apr 2013
Location: USA
Posts: 14
Received 0 Votes on 0 Posts
Cyrus, keep in mind that a mod/con needs to be installed with a primary/secondary piping arraignment. If you install the boiler yourself, this won't be much of an issue, but if you pay someone, this will add to the labor costs.
@drooplug thanks for the heads up. I will be tackling this myself (if I ever settle on a unit) so I understand the added labor for the (2) lines. The work isn't so much the issue, I actually look forward to doing things like this. The real issue is having the confidence in purchasing a product I will be happy with, not just short term, but long term. As much as I might enjoy working on the project, I don't want to be doing it again in 10 years, or worse. It doesn't seem as if anyone wants to put their name to a unit, so I guess it's up to me to try and make my best educated decision.

@Furd, feel better, you've already been a great help, no need to apologize.
 
  #25  
Old 04-30-13, 06:49 AM
D
Member
Join Date: Aug 2009
Location: USA
Posts: 4,947
Received 0 Votes on 0 Posts
Well, I have a Burnham and there was a Burnham installed for 23 years that I replaced. My in-laws recently replaced a Burnham of the same vintage. I can't speak for mod/cons and what to expect for longevity. My impression is that most of the brands you mentioned are good manufacturers. My plumber said he likes to install Burnham because they have really good support for their product.

You will find some good technical info here about boilers and their installation: Technical Menu
 
  #26  
Old 04-30-13, 07:13 AM
C
Member
Thread Starter
Join Date: Apr 2013
Location: USA
Posts: 14
Received 0 Votes on 0 Posts
@drooplug, that might be the single most informative site I've seen on this topic yet. Thanks a lot.
 
  #27  
Old 04-30-13, 07:33 AM
_
Member
Join Date: Dec 2010
Location: USA
Posts: 332
Received 0 Votes on 0 Posts
well that stinks. @_Diver did you end up going with a non-condensing boiler or go with a mod/con?
i still have my old boiler in my system. it's doing fine, but it's showing its age, it's 33 yo now. so i was simply thinking about the future system. i've started a good number of topics regarding mod con vs regular boiler. this is one is one of the examples.


i like the simplicity and reliability of non condensing cast iron boilers. but SS requirement for direct venting makes it close price wise to mod/con or it could be even more expensive. i'm not 100% swayed one way or another.

if i go with mod/cod, i think i will go with peerless pf-50 - this thread

if i were go to with a conventional i think i might go with slant fin victory vsph-60. my original choice was burnham esc-2, but now i think it's too large.

i want to get 1 quotes for the systems with boilers mentioned above and compare the cost with piping and venting included. base on the tax rebate incentives in the year when i have to actually have it installed i will make my decision on which one to go with.
 
  #28  
Old 04-30-13, 08:32 AM
C
Member
Thread Starter
Join Date: Apr 2013
Location: USA
Posts: 14
Received 0 Votes on 0 Posts
@_Diver judging by your selection pool, I see that your heat loss is just a little lower than mine, but reasonably in the same ballpark. Currently, my number is around 69-72k as I've done a few more runs through Wrightsoft. As I then plugged in my numbers for the anticipated envelope improvements for the house--really just adding storm windows, some blown cellulose attic insulation, basement wall and floor assembly insulation--the number DRASTICALLY drops to around 45k.

I am concerned that if I buy any boiler (mod/con or conventional) for my current heat loss, in a year or two when my improvements are done, I will be severely oversized (at least until an expansion of the home); however this should favor the mod-con boilers due to their modulation capabilities. For example, if I did go with the Peerless PF-80 (IBR = 64mbh), which would be pretty close to what I need, but way more than I need after tightening up the house. Could this boiler then modulate down to my needs on an improved home?

To reiterate, we need to get the tit of fuel oil, especially with my inefficient boiler and lack of DHW, so purchasing a new natural-gas fired boiler is imminent. Installing the boiler is unfortunately scheduled before the shell improvements, basically just out of necessity.
 
  #29  
Old 04-30-13, 08:50 AM
_
Member
Join Date: Dec 2010
Location: USA
Posts: 332
Received 0 Votes on 0 Posts
mod cons could modulate down, but i think it's still a lot more efficient to have a smaller size boiler to begin with. others will chime in - i'm not an expert in this are by any stretch

my heat loss is about 35k and i have about 45k of emitters. so pf-50 is perfect for me size wise.
 
  #30  
Old 05-25-13, 02:55 PM
C
Member
Thread Starter
Join Date: Apr 2013
Location: USA
Posts: 14
Received 0 Votes on 0 Posts
back again

so after putting out a few small fires (not literally, just the joys of being a first time homeowner) I'm back into researching boilers.

I picked up Dan Holohan's E.D.R. book and calculated that I have around 71500 of emitters--America Standard cast iron radiators on the main floor, a few cast iron baseboards in the basement. So to recap, 71.5K emitters and roughly 70K on my heat loss calc.

I have decided I'm going to take the gamble and go the mod/con w/IHWH route. I have purchased a roll of 1" CSST to run directly from my meter to my boiler--that is once I select one. With my original heat loss calc being around 69-72K, I am very much considering the Burnham ALP080 as I think it's heating capacity is listed D.O.E. as 73,000, which is very much near my heat loss.

A big plus for this particular boiler for me is that it's American made, which hopefully will help if/when I run into any problems. The price is right in the middle of all the boilers I have been looking at, so I feel that I'm not overpaying and I'm not cheaping out.

I'm always open to suggestions and pointers. My plan is to order material/parts and try to take care of the installation the first week of July, so if anyone else would like to chime in, I'd love to hear it. Thanks as always!
 
Reply
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: