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Outdoor reset, customer not happy at all

GW
GW Member Posts: 4,679
hello wet heads,

I went back to a job for an unreleated (to the boiler) reason the other day. I got an ear full when the door was opened. I installed a Vitogas100 with KW10 control a few years ago. I have two BB zones, with typical on-off zoning. She says her heating bill didn't drop at all. I kept my composure and asked if she noticed the THERMS going down at all; she claimed she gained absolutey nothing. Let me tell you, she was not happy at all; I think she was saving this conversation for 3 years!

I checked it out and all seemed fine. The curve is pointed at 2 just where I left it. The unit I took out was an original 50 year old beasty boy. The domestic is not in this equation; it's free standing gas HW.

When I told her I'd come back some day in the next week or two with my combustion analyzer and my blower door, and expalined what all that was, she cooled way off and even apologized to getting on my case.

So, my question is: Is conventional BB bad news with a medium-weight boiler on outdoor reset? The vito gas isn't a tiny boiler, nor is it a Vitola either. FYI, I rarely sell an outdoor reset control when it's just BB; I think there's little savings in the mild weather because the boiler is running non-stop just for a little amount of heat that is required.

Thanks for any input on this. Perhaps there's something wrong with the installation (???), or perhaps I've been brainwashed into thinking that outdoor reset is the most glorious thing since controlled combustion.


Gary
Gary Wilson
Wilson Services, Inc
Northampton, MA
[email protected]

Comments

  • ScottMP
    ScottMP Member Posts: 5,884
    Gary

    If you've got the curve set at 2 It looks to me like you gave her no reset at all. At zero degress she's getting 190°, wheres the reset in that ? I'd say thats the temperature she was getting out of the old beast.

    How about the size of the boiler, did you do a whole house heat loss ? Could it be over sized ?

    You own your own blower door test ?

    Scott



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  • .
    . Member Posts: 80


    I'm a HO myself, but I don't think most HOs know how to calculate savings. The savings due to outdoor reset is easily masked by variations in weather and price increases for NG. Did she calculate therms per degree-day? I don't think so. Even if one calculates therms/dd there are random variations.

    One should not overpromise savings due to reset. It is only few per cent in many cases---even less if the curve is not set as low as possible for the house, which is difficult for a contractor to do because it requires monitoring heat call durations in cool and cold and very cold days.

    The main selling point of reset is comfort.
  • S Ebels
    S Ebels Member Posts: 2,322
    Gary

    I have a goodly number of O/R BB systems running with curves from 1.4-1.6. The fudge factor here is the total amount of BB. All of those houses contain enough excess to allow reduced temperature operation. Do a heat-calc on the place and see how many btu's you need at design, then divide that number by the total feet of BB in the house. This will give you btu's/ft required from the BB. Check that number on an output chart for BB (someone had one posted here a few weeks ago) to find the water temp you need to work with at design. You might be suprised. I think the highest one I have running is on an undersized Hydro-air setup and that's still at 1.8 if I recall.
  • Joe Brix
    Joe Brix Member Posts: 626
    You can't realy say

    the HW heater is out of the picture. It's part of the gas bill also. Maybe there's a HW leak or HW use habits have changed.
  • GW
    GW Member Posts: 4,679
    I'm missing

    your jist, if it's 50 outside, the 2 will give me 100 ( the starting point is 65 or so, please forgive me for not recalling where that knob was set; I know it was just under 70, so lets call it 65 for now), if it's 30 out the temp will be 140. So I'm confused when you say there's no reset. The boiler is the 29 model; it's much smaller than the beast that was in there. I refuse to not consider a future storage tank. Heck, we caould arm wrestle for hours about heat loss. Unless you KNOW the infiltration and the R value, the heat loss program is a guess. FACT! (sorry firedraggon, but I like that!)

    I hooked up with Comfort Institute and got the blower door and some training. Talk about "wow", I never knew what I didn't know about thermal envelope, infiltration, and so on. I'm getting/got into the air side pretty heavily, so I have a couple of flow hoods and some duct diagnostic training fron National Comfort Institute.

    I have a competitor who has utilized my services when the mechanical engineer gave their duct system a "thumbs down" on a small school they did. Anyways, the blower door is fun especially on sales calls.

    Gary

    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • GW
    GW Member Posts: 4,679
    Thanks

    That's good advice. What strikes me is this: Even if the curve is high (I'll set it down), is it still unrealistic to expect some savings? Mind you this is not constant circ, it's just on-off. I think it's off base to consider this 2.0 way out there in outer space and therefore sucking all sorts of fuel. Please help me out if I'm wrong. Just a thought. My initial question- you're cool with outdoor reset on BB?



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    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • GW
    GW Member Posts: 4,679
    gas and electric

    This city has their own G&E plant/distribution, and it all ends up on one fat bill. She admitted she didn't know how to read the bill, so I'll be sure to make sure she has them in hand when I go back.

    So, all my wall friends, there certainly is some fudge factoring at this moment; there are lots of thigs I don't know for sure.

    If I crack the code and she sends me a box of chocolates, I'll let you know!

    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • .
    . Member Posts: 80


    It's not a matter of BB vs something else. It's a matter of how much radiation. If you have excess radiation, then even at design temperature you can be at much less than 180.

    Now generally it's hard to put in a lot of excess BB, whereas it is easy to put in an axcess of radiators.

    But the question is still, what water temp does that home need at design temp? Are you just guessing, or do you know? If you are guessing, you are probably guessing too high.

    Even if you need 180 at design temp, you need cooler water on warmer days, and then there is some saving. But not very much, not noticeable to the HO.
  • GW
    GW Member Posts: 4,679
    bb

    Chuckles,

    I'm guessing, but that's not what I'm getting at. A BB system has puny mass; it can't put a 'load' on the boiler, and the boiler cycles like a dog. A non reset boiler would run longer cycles in the mild weather (I'm talking BB here).I installed the reset control on this 3 years ago because I was told by the manufacturers that make this stuff that it was "awesome". I'm not so sure.

    I've got radiant in my house, Vitola, all that stuff, so I'm not bugged out at reset, it's the BB thing I'm not sure of.

    Anyways, when you do your heat loss, how do you come up with insulation and infiltation? Are you guessing or do you know? Do you know the R value of the glass? Doors? How do you determine it? Do you own a blower door? What if it's 70 inside and 70 outside; no way to even get out your IR camera to TRY to determine insulation in the walls. So go ahead an guess.

    Before I had wrightsoft and Elite, I've had AC jobs sized for me in the past where two suppliers came up with: 1.5 ton and 2.5 ton. Who was right?

    If I went in there (her house) with a vito 100 and no reset, are you saying that there would be even be more fuel consumed? A 2 curve is evil?

    I did a G124x chimney vent around the same time. cast iron heat. Couldn't get the guy to buy a 2107. He tells me a year leater he saved huge money/therms, my memory is not serving me so I'd prefer not to blow it out of proportion. So what's the deal? There is no canned answer here in my opinion.

    I'm gonna chill now, I'm sorry I got wound up. If someone is going to stick their finger in my eye and grab my nose because there is no heat loss invloved in this subject, I'll respond to that. The boiler is probably 30% smaller, higher tech (I guess), and she cranked on me because her bill didn't go down.

    Gary
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • GW
    GW Member Posts: 4,679
    also

    when you say: "Even if you need 180 at design temp, you need cooler water on warmer days, and then there is some saving. But not very much, not noticeable to the HO."

    I'm not follwing you at all. Of course the water is cooler on milder days, that's where the term "reset" comes in. Are we on the same page here? Did you mean cooler water on milder days?

    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • .
    . Member Posts: 80


    When the weather is such that the water is much cooler than 180, on those days you save. When it is very cold outside and the water is 180, on those days you don't save. When the water is only slightly cooler than 180, you don't save very much.

    So if your reset curve never needs to go above (say) 140 even on a design day, you save much more than if your curve needs to go to 180. That's what others in this thread are trying to tell you.

    If the smaller mass of the BB is causing short-cycling, that's not a reset problem, that's true with or without reset. If the boiler is correctly sized, short cycling should not be a major problem even with BB, because the load is not just due to the mass of the water in the radiation, it is also due to the heat loss of the house. Cycling can be reduced if necessary with a buffer tank or (even better) by increasing the delta-T of the aquastat.

    Since I am a homeowner, I can set the curve the right way...by looking at my thermostat each day and seeing how long the stat calls for heat, and lowering the curve until the stat calls for heat >16 hours a day in all weather (but less than 24 hrs a day!). Contractors can't be around long enough to do that.
  • Paul Pollets
    Paul Pollets Member Posts: 3,656
    Possible case for the Vitodens

    The Vitodens boiler would be better at matching load to actual demand....even if not in condensing mode. And I agree that the V100-29 is sized correctly for future Indirect DHW. The Vitotronic 200 would allow more control over the reset curve with parallel shift and could do the future DHWTank, but may not prevent short cycling. The boiler could still be oversized for the actual output of the boiler and it doesn't modulate. Is there an insulated chimney liner?

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  • LEAD PIPE
    LEAD PIPE Member Posts: 199
    My guess

    would be the reading of the bill. If her price hasn't changed over 3 years she has saved. Gas has gone way up in that time period. I have an ultra and BB and I have saved between 34 & 40% of gas used prior to its installation. If I just looked at what I spent and what I'm spending now it wouldn't look like that great a savings.
  • joel_19
    joel_19 Member Posts: 931
    something wrong

    I have used that configuration several times , and have saved people lots of energy every time. I'm in central Mass and have never found a house to need a 2.0 on BB 1.6 Max can get away with 1.4 on some. She must be looking at her cost not at her therms. I typically replace the WH with an indirect at the same time. We always downsize the boiler at the same time in many cases i'm still oversized because i can't convince the people to go smaller. they send me notes saying how much they saved with that very boilerI'd say she needs to take acloser look at that bill.

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  • ScottMP
    ScottMP Member Posts: 5,884
    Gary

    I did'nt say 2.0 was evil. I'm just saying its to steep to see significant savings.

    Yes, when I do a heatloss I guess ! I call it a educated guess. I can guess that a house built in the 60' has 2x4 walls and insualtion. A house built in 1900 has probable no insulation. I can look at a window and see that it has a single pane or a double. If they are new I can guess that they are low E. I can look up the r-value for a solid wood door or a hollow core, with or without foam. Most computer programs give a drop down menu. Its all a guess and none of it is an exact science, but you can get very close. Also I ask the owners what they know about the house. Owners can tell you alot if you only ask. I try and do a complete heat loss for every new boiler. I did say "try". :)



    Scott

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  • GW
    GW Member Posts: 4,679
    chimney

    is lined, this is a 50's vintage house.

    I think you are seeing what I'm trying to say...thanks Paul.

    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • John Cockerill
    John Cockerill Member Posts: 94
    reset dissatisfaction

    You could try taking thermostat demand over time and adjusting the boiler output that way. Adjusting the boiler temp every hour while circulating the water 60%, should make her comfortable and save 20% on fire time. And yes you have to tell her to correct for 20% price increase in the last year.

    John Cockerill Exquisite Heat
    www.Exqheat.com
  • Uni R
    Uni R Member Posts: 663
    First things first...

    You need to establish that she doesn't have any savings on the actual quantities of gas purchased. Therms used and degree days averaged over three years before and after. You show her the savings are there and then hopoefully she can't continue her rant much longer after that. If it's the price for natural gas rising that makes it look more expensive then you can make her feel better by pointing out how you were saving her money from the evil energy empires. =)
  • Dave_41
    Dave_41 Member Posts: 14
    Reset--

    First of all, reset does work on BB. I have BB in my own home and also have the most complicated reset know, it is ME. I look at the OD temps and manually reset the boiler temps every day, sometimes twice a day. I started doing this to see if reset was worth the money and just got in the habit of doing it. There is a new reset control still in the box on the shelf next to the boiler, some year I will get around to installing it!
    I do not think that there is any hard and fast rules about the curve settings for any particular installation. We determine each one seperatly based on info from data loggers. We log boiler run time/temps and room temps until we get a 65%+ pump run time and the minimum room temp variation. In retrofit situations we have seen the average savings to run from 10 to 45%. On all installations the data loggers are installed at startup and checked on a weekly basis until we and the HO are both happy, average is about two weeks to get everything working properly.
    Face it guys, this has turned into a high tech business, we do not have a blower door yet but we have several combustion analyzers and one thermal imager and many data loggers. The DL's are the cheapest tool we own and tell us more than almost anything else. They also do the work without you being there so there is very little labor involved. They are also about the only way to get your finger on those times when the HO has a comfort complaint and you can't see anything wrong, just install a DL and come back a few days later and the problem is usually very easy to see.
    Bottom line is that reset works in almost all situations, it just has to be set to the particular situation.

    Dave


  • GW
    GW Member Posts: 4,679
    data logger

    That's sweet! I have 12 hobo's and 3 Air Advice.

    I don't think anyone disputes the fact that o/r works on bb,
    it's simply we're kicking around how efficient it is.

    The KW10 (Viessmann) is a very limited control. I almost cringe having it installed on some jobs because hooking up DHW is a joke (there is no indirect dhw on this particular job). PLUS it doesn't have ww shut down (am I correct on this? It's been a while since I've installed one) Also it can't read a room sensor like the 2107 (Buderus) can. I know I can buy the Vitotronic 200, but I'm already "reaching" the customers "WIFM" (what's in it for me) on a Viessmann sale. That's one of the customer's biggest GRIPES, is she popped for "$800" more bucks to get the O/R control and she saw no savings (I would have to look back to the original price break down, so don't bust me on 800, that may have been for the whole Viessmann apgrade; I can care less- that's ancient history now). She and I and everyone here knows fuel has gone up; she says she didn't see saving from day one. Again, for the 9th time, this is percieved; it's what she is thinking and believes to be true, it may NOT be fact because she can't read (or doesn't care enough, or whatever the case may be) the utility bill! The town has gas and electric on one bill. She said last months bill was $500. It's a basic 2500 or so sq ft house. Who knows, mabe someone shut all the dampers on the bb units; I'll take a good look when I go back. Maybe some bird left the attic hatch open or ajar; I'll check all this stuff out when I hook up my blower door.

    If it COULD read indoor temp(the Viessmann control), I belive it would save some $ on fuel because it would not fire aimlessly in mild weather (50s and 60s) and run a REAL constant circ. That's what's nice about the 2107. I know the Vito 200 can do all that and more, but we're talking what, double or triple the cost?

    Happy Easter

    Gary

    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • Chuck_7
    Chuck_7 Member Posts: 71


    Where is the actual energy savings in reset?
    The heat loss from the house is the same either way (assuming the same setting inside). So the energy savings is in reduced loss from the boiler and piping which probably goes into the house any way. I'm not real fimiliar with the boilers mentioned above so after I leave here I will go look at thier web sites. Maybe some savings if they are condensing boilers and can be turned down pretty low. The pump(s) will run longer. I am looking at putting reset on a system with radiators and a cast iron boiler. I expect better comfort but little to no energy savings.
  • GW
    GW Member Posts: 4,679
    10 to 45%

    Wow, that's quite a swing. Here's is some logic that may need to be applied: It depends on how lame the old boiler was. A lot of times there could be significant savings just by forcing some more gpm through the piping (nothing to do with o/r, OR if it's a Viessmann or whatever).

    I've heard with my own two ears heating guys say wild claims how much savings could be expected if they went with "their" system. I'd love to be a fly on the wall a year later when comparative cold weather comes in.

    So, I have learned a big lesson (OK I already knew this and I'm sure everyone here knows it too): to promise savings is a risky ride. I never "promised" a thing on my job in question; I did toot the merits of the viessmann and the o/r control, which is why the lady gave me an ear full when I stopped by the other day. She paid me more of her hard earned cash to install this system; I SOLD it to her. Her expectations were let down. I have an obligation to try and figure it out.

    That's why the 2.0 curve on this job keeps coming up; I'm wondering if half the people who think it's too high actually know what the heck the 2 actually means! Of course it's setting back at milder temperatures! Geesh!

    I've taken out boilers and furnaces where they were full of crud inside. I could install a low end boiler/furnace and still expect big savings. No rocket science here. So, the mystery lives on. Might this old boiler at this house in question been running at peak efficiency giving its technology? Perhaps the 02 was wicked low and the combustion was hot hot, getting that energy to the water better. Where's Jim Davis? If everyone thinks low temp automatically translates to high efficiency, you're wrong! Get some combustion training!

    Anyways, it’s nice to see some people are chiming in here. I just know I've said some things that a LOT of heating guys think I'm nuts on; which is cool- let's hash it out. Thanks for all the replies on this!

    Here is a shot of my baby at home. All you wet heads who understand the mechanical glitch with this picture...I didn't know then what I know now. Can you all see it? The unit was installed in 1999, not 2002 or whatever the time stamp says.

    Gary
    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • Weezbo
    Weezbo Member Posts: 6,232
    someones doing something weird at her house to have had

    a 500$ G/E bill on 2500 square ft house. i would look to see if there is some problem with the Aluminum power entrance cables...i would start there...
  • GW
    GW Member Posts: 4,679
    savings

    There's a tale out there that says this: for every 3 degrees you can lower the output temp of the boiler, you save 1% in your fuel usage.

    So, if it's zero out, you save nothing (which is fine, because we're at zero what, 1 to 3% of the heating season?).

    But on the milder days much can be saved.

    If some engineer gets on this site and tells me that this 3 to 1 savings ratio is bogus, I'm gonna cry, because I've been using this in my sales pitch for years! Actaully Viessmann is where I learned this. I would hope the world leader in boiler manufacturing would not make this up.

    Now, there's a difference between reset and modulating firing rates. The reset idea fires the burner 100%, and changes the temerature of the water going out to the system. This is not to be confused with a heating unit that has reset AND modulating burner capacity (Vitodens, Munchkin with Vision, and I'm sure a host of others). Look at the warm air world. Most HVAC guys don't claim that a two stage burner saves money; it's simply there for comfort. Jim Davis states that it actually LOSES money; go figure- but he's the combustion man and I agree with his scientific ways.

    So, cast iron and hot water? I'd drool to get a O/R system in there WITH constant circulation and indoor sensor feed back to the pumps can run 24/7. Pump electricity? We're talkig peanuts here.

    Gary



    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • Chuck_7
    Chuck_7 Member Posts: 71


    I would say there should be a little savings but not enough to off set the rise in gas rates the last couple years. What exactly do they mean by 1% savings for 3 deg. temperature drop. Does that mean the boiler which starts out at 84% at 180 deg is running at 104% eff. at 120 deg?
  • ScottMP
    ScottMP Member Posts: 5,884
    Gary

    Maybe I am completly wrong, it won't be the first or last for me :)

    I have a Viessmann book. The technical data sheet for the Vitotronic 100 shows a heating curve. Thats what I was looking at. It shows the curve of 2.0 starting at 70 and going to 210 at zero°. If you went to 1.6 you would be getting (about) 180° on a zero degree day. I design most of my jobs around 180 at zero. So in my mind the 1.6 is a better curve. On certain jobs I have crept down 1.2.

    Am I not right in thinking a shallower curve gives better savings ? It also gets you closer to constant circ. Am I wrong to think that ?

    Did'nt mean to sound aggresive, its the keyboard thing. ;).

    Scott

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  • eleft_4
    eleft_4 Member Posts: 509
    edit

    Gary,
    please edit and use this resized one
  • MassDave
    MassDave Member Posts: 14


    For what its worth, over last summer I had a new oil fired boiler installed with constant circulation and outdoor reset system (both new to the system). Although I can't exactly compare last winter to this winter in Boston, my oil consumption is down 25% versus last year. Unfortunately oil prices are up 30% for me so the cost is almost exactly the same.

    It seems like I used less oil early in the season, but as was noted somewhere in this thread I am a lot more comfortable (no wild temperature swings in the house).
  • GW
    GW Member Posts: 4,679
    my heat loss program

    told me to use the size I used

    hee hee

    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • GW
    GW Member Posts: 4,679
    yo Scott

    I'm cool dude, we're all in this together; it's a fierce world out there. It's difficult to be the world's greatest service provider (all of us heating guys) on a daily basis. If I can keep everyone happy one day out of 5 I'm thrilled.

    The boiler has a high limit, so once it hits the limit, it shuts off. Your theory was correct; you just left this out of your reply.

    A 2 curve: outdoor temp goes down one degree, boiler goes up two degrees. That's was I was so harry about the replies I was getting; It was starting to sound like I was blatantly wasting the ladies fuel. Is 2 ideal? Maybe not. Better than not outdoor reset at all? Well yes I guess. That was the reason for the whole original post because the bb seamed to be not an ideal fit. I appreciate all of the comments though, thanks!

    Gary Wilson
    Wilson Services, Inc
    Northampton, MA
    [email protected]
  • eleft_4
    eleft_4 Member Posts: 509
    OOBOY!

  • eleft_4
    eleft_4 Member Posts: 509
    OOHBOY!

  • eleft_4
    eleft_4 Member Posts: 509
    OOHBOY!

  • eleft_4
    eleft_4 Member Posts: 509
    OOHBOY!

  • Mad Dog
    Mad Dog Member Posts: 2,595
    Is she aware that natural gas prices have gone up

    about 35-40% in the last 2 seasons? I don't think Long Island is too different from where you are. I am still learning the outdoor reset thing, so I will leave the advice to better minds. However, I have learned the hard way, you have to be very careful what you "sell" them on and fuel savings promises. I'm sure, the boys here will help you improve things. When I'm in a pickle like you are now, I quietly tell myself: "no guts, no glory....live by the sword die by the sword....I am hurt but I am not slain, I will lay me down and bleed awhile and rise to fight again....last one:....That which does not kill us makes us stronger. After you straighten this one out you will have learned. If this business were that easy, all the kids would be getting in to the trades. Good luck, Mad Dog

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  • Chuck_7
    Chuck_7 Member Posts: 71


    That is good info. Is the new boiler much more efficient?
  • John Cockerill
    John Cockerill Member Posts: 94
    no savings??

    Well your in for a 20% year after year savings. Enjoy.


    John Cockerill Exquisite Heat
    www.Exqheat.com
This discussion has been closed.