Page 2 of 3 FirstFirst 123 LastLast
Results 14 to 26 of 36
  1. #14
    Join Date
    Jan 2005
    Location
    Emerald Coast
    Posts
    933
    Quote Originally Posted by tedkidd View Post
    If you don't measure both ways you are guessing. Every house and the equipment therein are so different, that to know whether setback saves, does nothing, or even COSTS MORE is an unknown unless you actually test.
    .

    Every house is different.

    If the equipment is reliable ... go for it.

    But consider if the equipment should fault / breakdown or a power outage the house will become unlivable rather quick.

    ..
    Do not attempt vast projects with
    half vast experience and ideas.
    ...

  2. #15
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,770
    I turn my heat OFF in the morning. So it uses no oil until I get home and turn it back on. yep, a bit extreme. But its about as drastic a setback as you can do, and it does save me money. Yep, older house, and an older furnace. Reduces my oil usage by 250 to 325 gallons a year(50 plus hours a week of no oil usage).

    People that use a 5 to 10 degree set back in my area can save 50 to 100 gallons a year. So even though it may only save a quarter of a gallon a day, at 3.50 a gallon that adds up.

    People with Nat gas furnaces can save also. How much money wise of course depends on their gas rates.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  3. #16
    Join Date
    Jul 2008
    Location
    Rochester NY
    Posts
    4,702
    Awesome BT. You're pretty confident in those numbers? You have some way of tracking run times, and found allowing big swings reduced run, or somehow you tracked consumption?

    Would you say your furnace is oversized, so you are saving by having it operate long efficient cycles? (I'm not the only one who's kids go unshod..)

    Or you house is so leaky you aren't heating the outdoors as much when you go away?

    Here's an interesting post from LinkedIn:

    Steve EbelsHow people interact with the thermostat continues to be one of the great mysteries in my life as an HVAC guy. I probably spend more time each year explaining thermostats than I do the intricacies of anything else to do with my trade. .....and I gotta say it......most of the explaining is to the fairer gender. Ladies for the most part, have little comprehension of what a thermostat actually does and even less about what it is connected to. Hence their difficulty.
    With the women, the classic issue is "overdialing", as I call it, wherein if the person is too warm, the thermostat is set as low as it will go. If the person is too cold, the thermostat will be turned all the way up. There is no such thing as changing the setting just a degree or two. In building with radiant slab heating, one can only begin to imagine the havoc this can cause.
    My son went on a service call to a church toward the end of last winter. The complaint was no heat even though the boiler appeared to be running. Then when they came back the next day the building would be at 80*+. The janitor, a recently hired woman, would come in on Saturday to tidy things up and get things ready for Sunday services. She astutely observed that even though the programmable stat was at the 68* set point and the boiler was running, the building was only 60*. So she did the natural thing. She changed the setpoint to a higher number to....her words...."make the boiler run faster". Given that the boiler was working with a 6,000 sq ft slab, there was a considerable "flywheel" to get up to speed and once it got there it continued to shoot straight past the set point. You can easily imagine the response to an overheated building from this same person upon entering the building on Sunday morning and finding the temp to be 80+ in some cases........you are correct. It was turned down to 45*.

    One of my all time favorite places to work was a building owned by the state government here and staffed with about 60 women ranging in age from 30 to 60+. There were 9 zones in the building equipped with T-87's when I started with that account. We progressed to programmable stats and that did not help. Locked thermostat covers produced such an uproar that I am surprised you didn't hear it up in Canada Robert.
    Some were hot, some were cold, some were hot and cold, and those of the appropriate age swung wildly from one extreme to another. Interestingly the main complaint was not so much the fact that comfort was not adequate as the fact that they felt they had no control and were forced to "suffer in silence". We solved that problem by locking all thermostats at 67* and supplying the building supervisor with 30 small electric heaters the "cold ones" could put under their desks. Admittedly this is a little off the beaten path of heating nirvana but the super told me he actually had people go home because of discomfort at their work station..
    Sounds like examples of setback COSTING rather than saving.
    Which makes more sense to you?
    CONSERVATION - turning your thermostat back and being uncomfortable. Maybe saving 5-10%
    ENERGY EFFICIENCY - leaving your thermostat where everyone is comfortable. Saving 30-70%

    DO THE NUMBERS! Step on a HOMESCALE.
    What is comfort? Well, it AIN'T just TEMPERATURE!

    Energy Obese? An audit is the next step - go to BPI.org, or RESNET, and find an auditor near you.

  4. #17
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,158
    Here's your proof that setback saves money, a few screenshots showing my energy use. House is built 1999, 2 ton AC unit, 1600sqft. 4 people living in home. Decent insulation but not what I'd consider a high performance home. We have variable peak time of use rates along with an Energate smart thermostat

    Name:  9-5-12 cost.jpg
Views: 87
Size:  19.3 KBName:  9-5-12 kwh.jpg
Views: 79
Size:  20.1 KBName:  9-5-12 price.jpg
Views: 77
Size:  18.8 KBName:  9-10-12 price.jpg
Views: 80
Size:  18.9 KBName:  9-10-12.jpg
Views: 74
Size:  19.7 KB

  5. #18
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,158
    Excluding time of use rates, I think setback strategies are effective for low mass or leaky homes. High mass well insulated homes with properly sized equipment wont benefit as much. Of course if the house is well insulated with proper HVAC equipment the power bill won't be very much either way, little point in bothering with setback.

    Once time of use rates are factored in setback strategy makes a HUGE amount of sense for just about any home. All utilities will eventually get there, it's just a matter of time.

  6. #19
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,770
    My furnace is over sized. But I have it down fired to match the heat loss.

    Those figures are based on 11 years of living here. With the first 4 years not using set back. The next 2 years only using 10 degrees set back, and the last 5 years shutting the furnace off for the day. So I know my oil usage from year to year without tracking burner run time/cycle times. Along with having stuck the tank to compare usage from a weekend maintaining temp 24/7 to any 2 days of the week with set back/shut off on a couple of occasions.

    I also under fired the furnace for a while. And when I did that, I used more oil shutting the furnace off, and then taking 5 hours plus to recover on days when we were 20 or less outdoor temp(comparing to previous years of same temps). Perhaps only a 10 degree set back max when I had it under fired would have used less oil, but I never tried that. I just brought the firing rate back up. Except when I had it under fired, its been down fired to the heat loss for the entire 11 years.

    Reducing fuel consumption by just 4,000 BTUs a DAY can justify using set back.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  7. #20
    Join Date
    Jul 2008
    Location
    Rochester NY
    Posts
    4,702
    BT!

    That's what I need for high confidence. Long term committed no bs diligence.

    Do you think if you under fired and let swing less you'd end up at the same place? Possibly saving more on weekends to make up any diff?

    How does turning off impact mean radiant/comfort?


    Regcab, I think setback will completely change to thermal banking. Flywheel momentum of house mass will be strategically managed, and people will be rewardedforlocking multistage equipment on low during peak. Having discussions with grid consultants about this approach, as they look to avoid building more peakers.
    Which makes more sense to you?
    CONSERVATION - turning your thermostat back and being uncomfortable. Maybe saving 5-10%
    ENERGY EFFICIENCY - leaving your thermostat where everyone is comfortable. Saving 30-70%

    DO THE NUMBERS! Step on a HOMESCALE.
    What is comfort? Well, it AIN'T just TEMPERATURE!

    Energy Obese? An audit is the next step - go to BPI.org, or RESNET, and find an auditor near you.

  8. #21
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,770
    Under fired was more comfortable on milder days(above 20) due to the long run time providing a nice warm air for so long. It could hold temp until about 15 outside, then it loss temp. So on a cold weekend it would have used more oil running 24/7. And of course, during the week trying to recover I'd have to wear a jacket for 2 to 3 hours when it was below 30 outside. A smaller set back(say 4 degrees) would have shortened the recovery time. But still used a lot of oil during the day to maintain temp. I'm sure that there is an outdoor temp where min setback and under fired would have saved oil. But not as much as fired to the load, and turning off the heat during the day.

    No oil consumption for 10 to 14 hours(or more sometimes) saves a lot of oil.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  9. #22
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,770
    Quote Originally Posted by tedkidd View Post

    Regcab, I think setback will completely change to thermal banking. Flywheel momentum of house mass will be strategically managed, and people will be rewardedforlocking multistage equipment on low during peak. Having discussions with grid consultants about this approach, as they look to avoid building more peakers.
    Problem with thermal banking. If regen/recharge occurs at the same time for everyone, you just changed when peak load occurs.

    Back around 93 PPL asked businesses in Harrisburg to close early, and or call off their second shift, so they wouldn't have to black out sections to prevent the whole area from having a black out that would last for hours. Those people with off peak storage systems would have been screwed if the grid went down for more then an hour or 2, as their systems wouldn't have been able to recharge in just 3 to 4 hours.

    There are pros and cons to off peak storage.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  10. #23
    Join Date
    Jul 2008
    Location
    Rochester NY
    Posts
    4,702
    Yeah, I think a big part of the difference is indirect vs direct control. If a blind man is driving and you are instructing from the back seat,you might go off the road once in a while. Technology will give grid operators direct control, although pricing strategies like regcab lives with may be a big player.

    Back to the furnace. So setback didn't seem to save, but plain shut OFF saves a fair amount. How much of your total usage does 250 gallons represent?

    Fixed blower or ECM? Duct leakage to outside? Enclosure pressure imbalance? Thinking these costs could be a problem with longer runtimes. Lower pressures from lower stages seem to save on a lot of fronts.

    How much does colder return air pulling more heat through HE play in it you think?

    With historical data that good it'd be fun to change the equipment and start the experimentation all over again. When will that be happening?

    We took oil out of my fiancées place and put in an infinity, and spray foamed her roof deck. Took her from 400 gallons (7 year average) to 300 therms. What's the cost swing today, from $1400 to $300?
    Which makes more sense to you?
    CONSERVATION - turning your thermostat back and being uncomfortable. Maybe saving 5-10%
    ENERGY EFFICIENCY - leaving your thermostat where everyone is comfortable. Saving 30-70%

    DO THE NUMBERS! Step on a HOMESCALE.
    What is comfort? Well, it AIN'T just TEMPERATURE!

    Energy Obese? An audit is the next step - go to BPI.org, or RESNET, and find an auditor near you.

  11. #24
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,770
    Quote Originally Posted by tedkidd View Post
    Yeah, I think a big part of the difference is indirect vs direct control. If a blind man is driving and you are instructing from the back seat,you might go off the road once in a while. Technology will give grid operators direct control, although pricing strategies like regcab lives with may be a big player.

    Back to the furnace. So setback didn't seem to save, but plain shut OFF saves a fair amount. How much of your total usage does 250 gallons represent?

    Fixed blower or ECM? Duct leakage to outside? Enclosure pressure imbalance? Thinking these costs could be a problem with longer runtimes. Lower pressures from lower stages seem to save on a lot of fronts.

    How much does colder return air pulling more heat through HE play in it you think?

    With historical data that good it'd be fun to change the equipment and start the experimentation all over again. When will that be happening?

    We took oil out of my fiancées place and put in an infinity, and spray foamed her roof deck. Took her from 400 gallons (7 year average) to 300 therms. What's the cost swing today, from $1400 to $300?
    Set back saved/saves, just didn't with the under fired nozzle. Turning it off saves more.

    Belt drive blower. Leakage to basement but not to outside(all duct work in the basement). No imbalance of pressure in the house, with the exception of the kids room when the door is closed.

    Colder return air of course gets greater heat transfer rate.

    Unless the heat exchanger burns through, won't be changing it out. Almost got around to making it dual fuel this fall, but didn't.

    400 gallons here today would be $1352.00

    How big is here place.

    If the old oil furnace was 80% efficient and the new gas furnace is 95% efficient. Then you reduced the equipment's BTU consumption by 46.5%, and actual BTUs needed delivered to heat the home by 36.4% However, since two variables were changed at the same time, which one reduced the heating cost the most is not known.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  12. #25
    Join Date
    Nov 2006
    Location
    Athens, Ohio
    Posts
    1,702
    Re. underfiring - I've had to re-think my position on that. I took Jim Davis's combustion analyzer class last week and he raised the matter or what happens to heat transfer and efficiency when the flame is lowered. I was especially interested since I have a two-stage furnace.
    Jim's point was this - when the flame is lowered the gases at that point are farther from the heat exchanger walls and that lowers the efficiency of what should be the hottest part of the furnace. I recalled that every time I check the efficiency of a two-stage condensing furnace, the low-fire efficiency is below 90%. High-fire is up where I expect it to be, in the mid to high 90s. I'm considering raising the firing rate of low-fire as high as I can get it to maintain the efficiency rate of the furnace.
    What do you guys think?

  13. #26
    Join Date
    Jul 2008
    Location
    Rochester NY
    Posts
    4,702
    She has a poured cement house, 2 story's, about 900 sf.

    Yes, poured cement. Not much gonna improve those walls, but they certainly aren't leaky. Attic was leakage and insulation opportunity.

    I'm seeing savings beyond prediction from aggressively downsizing equipment.

    I think load matching, cold return, low fire (more transfer surface per btu), low ecm amp draw, and improved duct performance from the cooler output air and lower pressure/leakage, AND improved comfort resulting in less "fiddling", all have a pile on effect.

    I think the wetheads understand this best. This great article from Dan Holohan really put it in perspective for me.

    Here's another one that talks about low and slow...

    http://www.healthyheating.com/Boiler...m#.ULfJYazBHoJ

    a boiler rated at say 98% only achieves 98% when it sees less than 80 deg F (27 deg C) return water temperatures (Fig. 2) regardless of the heaters Energy Star rating or use of programmable setback thermostats. This is not a trivial matter as the cost to upgrade equipment and controls can be significant and all will be for not from an energy perspective if it doesn't lower fuel consumption.
    (So, how do you insure low return water temperatures? Certainly not by attempting fast recovery...)
    Last edited by tedkidd; 11-29-2012 at 06:37 PM.
    Which makes more sense to you?
    CONSERVATION - turning your thermostat back and being uncomfortable. Maybe saving 5-10%
    ENERGY EFFICIENCY - leaving your thermostat where everyone is comfortable. Saving 30-70%

    DO THE NUMBERS! Step on a HOMESCALE.
    What is comfort? Well, it AIN'T just TEMPERATURE!

    Energy Obese? An audit is the next step - go to BPI.org, or RESNET, and find an auditor near you.

Page 2 of 3 FirstFirst 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event