Newbie with Alpine issues

Discussion in 'Boiler Forum' started by tom3holer, Mar 2, 2013.

  1. tom3holer

    tom3holer New Member

    Messages:
    40
    Location:
    Cape Cod
    Hi,

    I am new here and this is my first post.
    Was up till 2:30 this morning reading all I could and am so impressed at the level of advice and knowledge on this website.

    My home, located on Cape Cod Ma, is an old Sea Captains house built in 1860 of around 3000+ sq/ft. It was retrofitted at some point before I bought it 22 years ago with baseboard fin tube raidiators. The downstairs is divided into 3 zones and the upstairs is one zone for a total of 4 zones. 10 years ago we had cellouious blown in insulation done. It was a poor job as I have found many gaps over the years during remodeling.

    To the issues. I replaced my 20+ year old W/M VHE gas boiler with a Alpine 150 this last Spring. I also had installed by the same plumber a new superstor 45 gal water heater. All seemed fine till we got into the colder months of the Fall and this Winter. The kitchen in particular on days of 30 and below I could not get above 68-69 deg many mornings. The raidiators seemed sometimes hot, but most of the time luke warm to almost nothing. This all while the tstat was calling for heat. The boiler would fire and come up to temp then shut down. This naturally went through the long startup process thus keeping the average water temp low. The installer which I called over didn't have a clue as to why it was shutting down with one or more zones calling for heat. I read the manual and did spent a good deal of time in the basement watching the boiler run. It didn't take long to realize what was going on.

    The default "Central heat diff above" is only 2deg. It was always overshooting and thus shutting down. I upped this to the max of 10deg and that was much better. It didn't short cycle as much. I did read in the suppliment to the owners manual that the new rec setting is 5 deg. I insisted the installer contact the factory rep for our area and ask him to come over and look at the installation. I realized after asking the installer if he had tweeked any of the settings and he replied "Na I just leave them at the factory settings, he didn't have a clue. The factory rep came over with my installer, but didn't seem to offer any suggestions. He lowered thew central heat mod from 5000 to 4900 but that was all.

    I would like to tweak this system to get the best effiency I can and have no quams calling an engineer over to elaluate the setup and settings but not sure there is one here on the Cape.

    From what I have read I am way over boilered. I have Taco pumps on each zone which most likely flow way to many GPM.
    The manual calls for 160-190deg water for the baseboard I have. From what I have read isn't 140 more in the range for best effiency?

    Thank you in advance for any suggestions and advice,

    Tom
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,053
    Location:
    New England
    Hindsight is what can cause you to kick yourself...yes, it is likely the boiler is oversized. An outside reset control would adjust the boiler setpoint to the need, rather than using a fixed temp. Multiple zones may be making the problems worse with a big boiler since it can't modulate down far enough to accommodate the actual load except maybe on the coldest days. The baseboard heaters have a variable heat output that isn't quite linear, especially as you get approach the lower range, but they still produce heat. The idea of the cooler radiators is to adjust it to your need and to get the return water cool enough to allow the boiler to run in condensing mode, reaching its maximum efficiency.
  3. tom3holer

    tom3holer New Member

    Messages:
    40
    Location:
    Cape Cod
    Jim

    Thank you for the reply. On the down stairs we have 3 zones. One in the kitchen and the other two for the other rooms. I am considering combining the other rooms into one tstat, so that tstat controls both circulators. Will have to check the data sheet on the Taco SU-504 zone controler and see if it can handle two circulators
    .
    A couple of things I am having trouble understanding are:

    The Alpine manual calls for 160-190deg setting for the fin/tube baseboard the house has. At those temps the Delta T will never be high enough to have the return water get to 120 or so, as as I have read it needs to be, for the condensing part to work.

    The previous system had a VHE boiler with a Suporstor 45 or 50 gal indirect water heater. We ran out of hot water quite frequently even in the summer. We do not take long showers either. The new system is using a new Suporstor 45 gal tamk. The installer said you should be able to run the hot water continously and never run out. The DHW priority was wired wrong as I discovered and had him come back and correct it. Still, last evening my wife ran a load of wash then after the washing maching has stopped using hot water she took a shower, half way through the shower she said she had the knob up to full hot and it was bairly hot enough.
    The basic problem I see here is similar to what I saw before only somewhat exagerated. The HW is set at 135deg and at some point the HW tstat senses the tank water is getting too coll so it calls for heat. Now the whole prepurge etc. cycle starts and its a while before it fires off further lowering the water temp. By the time its up to speed the cold incomming water had lowered the tank to an unacceptable temp. Is this just an inherant problem with this type of DHW system or is there perhaps a way to change the tstat so it will kick in earlier so as to get a head start?

    Thanks again,

    Tom
  4. tom3holer

    tom3holer New Member

    Messages:
    40
    Location:
    Cape Cod
    Jim

    Thank you for the reply. On the down stairs we have 3 zones. One in the kitchen and the other two for the other rooms. I am considering combining the other rooms into one tstat, so that tstat controls both circulators. Will have to check the data sheet on the Taco SU-504 zone controler and see if it can handle two circulators

    A couple of things I am having trouble understanding are:

    1: The Alpine manual calls for 160-190deg setting for the fin/tube baseboard the house has. At those temps the Delta T will never be high enough to have the return water get to 120 or so, as as I have read it needs to be, for the condensing part to work.

    2: The previous system had a VHE boiler with a Suporstor 45 or 50 gal indirect water heater. We ran out of hot water quite frequently even in the summer. We do not take long showers either. The new system is using a new Suporstor 45 gal tamk. The installer said you should be able to run the hot water continously and never run out. The DHW priority was wired wrong as I discovered and had him come back and correct it. Still, last evening my wife ran a load of wash then after the washing maching has stopped using hot water she took a shower, half way through the shower she said she had the knob up to full hot and it was bairly hot enough.
    The basic problem I see here is similar to what I saw before only somewhat exagerated. The HW is set at 135deg and at some point the HW tstat senses the tank water is getting too coll so it calls for heat. Now the whole prepurge etc. cycle starts and its a while before it fires off further lowering the water temp. By the time its up to speed the cold incomming water had lowered the tank to an unacceptable temp. Is this just an inherant problem with this type of DHW system or is there perhaps a way to change the tstat so it will kick in earlier so as to get a head start?

    Thanks again,

    Tom
  5. tom3holer

    tom3holer New Member

    Messages:
    40
    Location:
    Cape Cod
    Jim

    Thank you for the reply. On the down stairs we have 3 zones. One in the kitchen and the other two for the other rooms. I am considering combining the other rooms into one tstat, so that tstat controls both circulators. Will have to check the data sheet on the Taco SU-504 zone controler and see if it can handle two circulators

    A couple of things I am having trouble understanding are:

    1: The Alpine manual calls for 160-190deg setting for the fin/tube baseboard the house has. At those temps the Delta T will never be high enough to have the return water get to 120 or so, as as I have read it needs to be, for the condensing part to work.

    2: The previous system had a VHE boiler with a Suporstor 45 or 50 gal indirect water heater. We ran out of hot water quite frequently even in the summer. We do not take long showers either. The new system is using a new Suporstor 45 gal tamk. The installer said you should be able to run the hot water continously and never run out. The DHW priority was wired wrong as I discovered and had him come back and correct it. Still, last evening my wife ran a load of wash then after the washing maching has stopped using hot water she took a shower, half way through the shower she said she had the knob up to full hot and it was bairly hot enough.
    The basic problem I see here is similar to what I saw before only somewhat exagerated. The HW is set at 135deg and at some point the HW tstat senses the tank water is getting too cold so it calls for heat. Now the whole prepurge etc. cycle starts and its a while before it fires off further lowering the water temp. By the time its up to speed the cold incomming water had lowered the tank to an unacceptable temp. Is this just an inherant problem with this type of DHW system or is there perhaps a way to change the tstat so it will kick in earlier so as to get a head start?

    Thanks again,

    Tom
  6. tom3holer

    tom3holer New Member

    Messages:
    40
    Location:
    Cape Cod
    Sorry for the triple post, My bad.

    I am having a bit of trouble with my good old IE and this website......

    Tom
  7. BadgerBoilerMN

    BadgerBoilerMN Master Hot Water Mpls,MN

    Messages:
    303
    Location:
    Minneapolis
    Nothing beats a condensing boiler for space and domestic hot water heating. They are more efficient, create more comfort and domestic hot water, at a lower operating cost per dollar invested than anything on the planet...if the system to which they are attached is properly designed, installed and maintained.

    Your problem is with the installer. Call the factory and ask them for the a local certified contractor. The contractor will need to check the piping and pumping arrangement and then set the ODR to fit your climate and your "radiation". Fin-tube can be reset for temperature, but the slope is steep and the range short. If there is in fact no factory trained technician in your area (unlikely) you may call any factory trained Alpine boiler technician offer to pay him to evaluate your system over the phone. This should be done with the aid of some pictures and data then changes made with your "plumber" present. We do this all the time for contractors and homeowners alike. If it is just a programming problem the homeowner may be sufficient. If the system must be re-piped the plumber must be convinced to do what's right.

    The DHW is a critical sub-system that must be properly designed, just as the boiler should be sized for the heating load. The indirect water heater specified should certainly keep up with the loads you describe as it is fired at nearly 3 times the rate of a standard gas-fired, low efficiency, tank-type, water heater. There are many ways to control the indirect, depending on the various components used and how the boiler controls interface with it.

    Most indirect water heaters should have a mixing valve, tempering the DHW set to 140°F and mixed back down to 120°F or so, thus extending the dump and draw-down capacity.
  8. tom3holer

    tom3holer New Member

    Messages:
    40
    Location:
    Cape Cod
    Badgerboilermn,

    Thank you for the reply. The first thing I plan doing is to have a good heat loss evaluation done. I keep hearing a recomendation for a "Manual J" heat loss done. If I can find someone that actually can do it locally what can I expect to pay for the evaluation? I know it will be well worth it even thought it should have been done before the installation.
    So is it possible to actually get the burner into a condensing mode when running the recomended output temps of 160-180? As mentioned before the factory rep came by with my plumber and changed the mod rpm down 100 and went to reset the over temp limit that was factory set at 2deg but I told him I had already done that and that was all. He did ask my plumber came up with the 150 size and he told him that was what he pulled out. He didn't comment but I think it was out of respect to the plumber with me being there.
    You must be busy in Msp. I just retired from Northwest now Delta as a pilot and spent many cold days in the Cities at our training center.

    Thanks again, I'll post again when I get the evaluation done and find a factory trained tech.


    Tom
    Thanks a lot for all the advice guys.
  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,053
    Location:
    New England
    Fintube convectors rely on there being a big enough temperature difference to create a draft around it to convect the air through them to heat the room...a flat plate or old clunker works better at simple radiation. But, they will produce heat at a lower temperature, just not as effectively. Most days, you do not need their max output. If you study the spec sheet, they'll give BTU output at various inlet temperatures. They can only generate their maximum heat when you supply them with a narrow range of hot water, but they will continue to work at a lower temp...the spec sheet should describe that.

    Most boilers can be set to adjust their outlet temperature based on the zone. On mine, it normally runs at no more than 130-degrees outlet until the IWH calls for heat on its priority zone, then it fires up to 190-degrees or so until the IWH demand has been met. With a small 45-gallon tank and that large boiler, it should be able to keep a shower going for a very long time. Dumping most of it to a tub or washing machine first means it has to start from a much lower temp, though. While I probably could have gotten by with a smaller tank, I have a 60-gallon IWH so I can fill a large 6' air tub. I also wanted to be able to take a long series of showers, as when I have house guests, and one bathroom (small condo), I didn't want to run out. With the boiler I have, and that tank, you could shower pretty much all day and not run out. It does take a few minutes to recover after filling the tub, though.

    WHen I did my bath renovation, I put in a thermostatically controlled tub/shower valve...it adjusts itself as the WH tank's outlet temp drops until it's using all hot, if that's what's required, to maintain the user's set temperature.

    I'd also bump the IWH setpoint to 140-degrees to raise the amount of energy stored there, but only after installing a tempering valve, if it doesn't already have one.
  10. tom3holer

    tom3holer New Member

    Messages:
    40
    Location:
    Cape Cod
    Jim,

    Thanks again for the reply. No it does not have a temping valve. The plumber initally set it to 120deg and said that will work fine.
    That is on the list to do. Tomorrow I hope to locate a good heating tech to do a heat loss study. Is the Manual J really rthe way to go as I've read?

    Tom
  11. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,053
    Location:
    New England
    Unless you're prepared to possibly change the boiler, it would be good info to have, but may not help much. There are ways to make what you have work better, possibly a buffer tank, and possibly combining zones so the load is bigger, but that would somewhat depend on what the manual-J analysis says.
  12. tom3holer

    tom3holer New Member

    Messages:
    40
    Location:
    Cape Cod
    I do realize I am probably stuck with the boiler I have but the Manual J would help with deciding how bad it really is.
    Now to find someone in my area that knows how to do one.

    Tom
  13. BadgerBoilerMN

    BadgerBoilerMN Master Hot Water Mpls,MN

    Messages:
    303
    Location:
    Minneapolis
    Some "condensing" boiler will feature multi-zone temperature control and all now have DHW priority and will run to a relatively high "fixed" temperature for making DHW. Your fin-tube should be set to a relatively high design temp, but as jad suggests, this is for the coldest few days of the year. In the shoulder months the average water temperature should easily bring the return below 130°F where a boiler will begin to condense and exceed the AFUE number printed on the yellow tag.

    More than being essential information, the "Manual 'J' is a good indicator that your heating technician is brighter than average and at least smart enough to have his local distributor produce on for him. No smart contractor will produce a good heat load for free but he should be able to show you a sample of his work. The smart Burnham Alpine contractor will also know that this particular ModCon can be de-rated in the field. This does not cure all the ills of an over-sized condensing boiler, since the minimum output will likely be too high still. But it can help.
  14. tom3holer

    tom3holer New Member

    Messages:
    40
    Location:
    Cape Cod
    I called a couple of contractors today and found one I think I will be pleased with. The gal answering the phone knew exactlly that I was talking about when I asked if they could they do a "Manual J" alanysis. She was very surprised whenI told her the plumber that replaced my boiler never did one. She said we would have to charge you and I said absolutely I expect to pay for it. She thought it should run 1- 1/12 hours. She also said their head tech which would do the alalysis was trained by Burnham on the Alpine. So lets see what he comes up with.

    Tom
  15. Dana

    Dana In the trades

    Messages:
    2,864
    Location:
    01609
    This system is probably an efficiency & operational nightmare- not only is it broken up in to four zones, the boiler is about 3-5x oversized for the space heating load. Typical pre-1980 20th-century construction usually comes in at roughly 15BTU/foot of conditioned space in eastern MA, but it varies by quite a bit- 20BTU/ft is on the high side, and usually rectifiable to something lower in a cost effective manner with air-sealing and insulation measures.

    The window/floor ratios of 1860s construction is typically 1/2-2/3 that of typical mid-20th century construction, and even if it has original double-hung single-panes tightened up with storm windows rather than code-max U0.34 double-pand, with some amount of air sealing and retrofit insulation they rarely break very far out of the 15BTU/foot at the ~10F 99% outside design temp. ( Only in rare instances is it not possible to retrofit-weatherize a mid-19th century antique into that range without creating a condensation & rot problem. On early 19th century houses with clapboards nailed directly to the studs, no sheathing it can be a real problem if you insulate. But wide-plank sheathing with paper air-barrier under shingle siding was pretty common on Cape Cod by 1850, and that's usually something that can be insulated safely.) Assuming your contractor managed to insulate at least 2/3 of the wall area, and have some amount of attic insulation, its unlikely you'd be as high as 25BTU/foot, but a careful heat load calc would tell all.

    Even at 25BTU/ft that boiler is still 2x oversized for the whole-house load, and probably more than 10x oversized for the smallest zone. If the zone with the shortest total length of baseboard can't deliver a large fraction of the minimum fire output of the boiler at a condensing temp (125F average water temp max), it's going to short cycle. Combining zones or adding radiation is likely going to be in order to tame this beast, even with a field-derating fix.


    For yuks, assuming you have storm windows or clear-glass double panes add up all the window area in square feet, as well as the doors, and multiply that by (U0.5 x 60F=) 30 BTU/foot. Then add up all of the wall area (less windows & doors), add that to the attic floor are an multiply it by (U0.1 x 60F=) 6 BTU/foot. Add your windows & doors BTUs to your wall & attic BTUs, that's going to be the very rough heat load of the house, unless it's the draftiest, leakiest house on the Cape (and that can be rectified.). The true heat load at 70F indoors/10F outdoors won't be 2x that, even if with some air leakage and insulation gaps (and no foundation/basement insulation.)
  16. Dana

    Dana In the trades

    Messages:
    2,864
    Location:
    01609
    The other very-excellent way to get a handle on the whole-house heat load is to use the boiler as a measuring instrument, charting fuel-use against heating degree-day data. Most gas utilities in MA post both a daily fuel use and average outdoor temperature for the billing period. First, calculate the average heating degree days by subtracting the average temp listed on the bill from 65F. eg: If the billing says it averaged 34F, the average HDD is (65F-34F=) 31 HDD

    Then multiply the fuel-use number by the name-plate efficiency or AFUE of the boiler (if you've been running only 150F+ output temps, use 0.87, not the AFUE number). eg: If the billing says it was 6.4 therms per day and the boiler's AFUE is 93, the boiler output was (6.4 x 100,000BTU/therm x .93= ) 595,200 BTU/day.

    Then calculate the BTU per degree-day by dividing your BTUs by the HDD:

    595,200/ 31= 19,200 BTU/HDD

    From there, get BTU per degree-hour by dividing by 24 hours in a day:

    13,200/24= 800 BTU/degree- hour.

    To find your heat load at +10F, first calculate the difference from your base temp of 65F (outdoor base temp, not indoor), to get

    (65F-10F =) 55F

    Then the heat load is your degree-hour number times 55F: 800 x 55F= 44,000 BTU/hr

    Even with overnight setbacks etc, the fuel-use calculated number is going to be an upper bound, since it did not correct for hot water, clothes drying or cooking use. And if the thing was short-cycling or running at a non-condensing temp it'll also be on the high-side of the real heat load. The best thing about this method is that it doesn't matter how the house is built, how leaky it is, or how many gaps are in the insulation, or what types of windows it has, all factors which would add error to a Manual-J. It's not an calculated estimate- it's a MEASUREMENT. Although there are inherent errors in the measurement, it's a smaller error than for Manual-J, if it's done on a mid-winter billing period.

    But unlike Manual-J, it tells you nothing about the room-by-room or zone-by-zone issues, which are still important from a system design point of view.
  17. tom3holer

    tom3holer New Member

    Messages:
    40
    Location:
    Cape Cod
    Again thanks everyone for the help and advice.

    Two days ago the heating tech from a large heating contractor came over to look things over. He spent over an hour looking over the boiler setup and took measurements of all the rooms in the house. I had asked for him to come over and do a Munual J so as to see exactly where we were. He didn't think a manual J would be much more accurate than the shorter method he wanted to use. He said that in older homes like mine ,1860, that the manual J was kinda a wag as there was so many variables. I agreed and received the heat load estimate yesterday. The home is a 1860 built mansart roof of about 2300 sq/ft. I have 166 feet of baseboard all being regular except the kitchen which is 30 feet of Hicap.All exterior walls have had blown in celious (sp) insulation, with some gaps. Two floors and attic with 3-4 inch of rock wool. Windows are, for the most part, older double hung but all have dead glass interior inserts and others are all thermopane with kitchen being all Anderson. There is 166 feet of baseboard all being regular except the kitchen which is 30 feet of Hicap Three quarter full basement unheated. I think his estimate is on the high side but he came in at 91,460 BTU heat loss at 0 deg. With that heat loss he thought the Alpine 150 was probably slightly oversized but the next one down, the 105 would be too small considering we also have SuporStor SSU45 being heated by the boiler. I think I will do some calculations on a few rooms myself using some simplified manual j type math I have found here to see if we agree. It does seem quite high to me. I did use the 25btu/cu ft quickie. Based on the square footage and cieling heights of 8.5 ft. I came out slightly more than half of what he calculated.

    Dana, I get my gas from "National Grid" and do not see anything on the bill about an average outdoor temp. I will give them a call and see if its available.
    Also
    As always, thanks for the help

    Tom
  18. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,053
    Location:
    New England
    This has been discussed lots of times...you can get a fairly good idea of your actual heat load by knowing how much gas you've used. Since each 100cuft or whatever measure they use produces a fairly well known amount of heat to burn it, then the efficiency of the boiler used to burn it compared to the degree-day for the period in question. Degree-day info is readily available for free for your zipcode. While that guy may have talked a good line, I think he's likely full of it...
  19. tom3holer

    tom3holer New Member

    Messages:
    40
    Location:
    Cape Cod
    I took the numbers from several months and they were quite consistant.
    As the Alpine return temps as it set up now very seldom get into the con mode I used .9 as an efficiency number.

    I came up with an average of 71,822 at 0deg OAT and 60,756 for 10deg OAT

    I used 90% as the efficiency number and the National Grid published average OAT for the months calculated.

    As the output temps usually are above 150deg then the numbers would even be lower.
    We do heat DHW with a Superstor connected to the boiler and stovetop and drier are gas. Just the two of us now so drier and cookong is not excessive.

    As a note, I had a large contractor sent their senior tech over to do a Manual J calc on the home.
    He spent time looking at the boiler setup and said he would get the Tech rep from Burnham over with him in a week or so to go over tweaking the setup.
    He did not seem to want to do a full Manual J and said instead he would do a heatloss calc that should work as accurately as the manual J is not as accurate on an older home. I agreed as he was spending a lot of time just answering my questions. He emailed me the results and I thought they were way off and after doing the "Fuel Used " method I am sure they are off. He said the heatloss was 91,470 at an OAT of 0deg.

    He will be comming over next week with the Factory Rep and I will show him the results I came up with.
    I read here, I thought, that a factory rep has the ability to derate the boiler system. If so does that mean they can lower the min fire rate? That would be nice but thought that the min fire rate was as low as it could go and still burn properly.

    Thanks again for any suggestions,

    Tom
  20. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,053
    Location:
    New England
    When you use the fuel for multiple items, it's best to subtract a summer month when heating the house is not happening, from a winter month. Otherwise, you're calculations are going to be off, maybe way off. It is a rare day when your boiler would need to be running constantly at full output. As a result, making it bigger to account for the water heating is a big waste. So, if you averaged say 50 therms in the summer per month and 450 in a winter month, your actual heating load would be 400, not 450; the rest being water heating, cooking, drying clothes, or whatever.
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