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cindywhitall

bills are lower w/new system

cindywhitall
11 years ago

I wanted to share that I think my investment may have been worth it in my upgrades this year. It may not pay for itself totally, but my bill was $55 lower for gas and $24 for electric. Don't know how electric rates have changed since one year ago. BUT, my bills for Jan were $79 lower AND my monthly payment for the work I got done is $83. (zero interest).

Just got my January bill and it is 25% lower than last year despite it being 1 degree colder, per South Jersey Gas. My therms used were down 25% from 173 to 130 and the payment due was also 25% lower. December was only down about 17% which I barely noticed, the price was $114 vs $138 the year before.

I got my old (approx 57% eff) gas hot water heater replaced with the tankless (95% navien). My 126k, 90% btu furnace replaced with 97% 100k btu (and I know it's a little oversized....but figure 2 stage helps compensate) and the air sealing done in the attic.

Something apparently worked to bring my bill down! I know the efficiency of the furnace is not that different, but I assume it was helpful that it probably ran often in 1st stage around 66btu instead of my old one only ran at 126btu.

My electric is still high . Used 875 kwh this year and 1010 last year, could be savings from LED xmas lights for one week of the bill. It's gone up over the years, probably due to the young adults each having a TV and a computer as well as me and hubby.

Just wanted to share in case anyone else is contemplating upgrades and/or air sealing.

Comments (15)

  • Elmer J Fudd
    11 years ago
    last modified: 9 years ago

    I'm glad you're happy with your new equipment, you invested a lot of time and effort in the project.

    If your savings in months of heavy usage don't provide enough of an excess, when you factor in having a net cost in months of lighter usage (as you saw in December) you'll likely be in a net cost position each year. That's perfectly fine if you're happier with how it operates compared with before. Whatever savings comes from system efficiencies will continue after the loan is paid off and you could be net positive at a later date.

    Other than in cases of really old equipment or houses in dire need of modernization, or places with extreme weather, it can be hard to get a positive economic return from optional heating/cooling improvements. I think it's better to think of this area as a cost (in any event), and make improvements that change or improve performance to be how you want it to be. When you can do that, the cost is justified.

    Good luck

  • energy_rater_la
    11 years ago
    last modified: 9 years ago

    has comfort improved?

    how long until you pay off equipment/upgrades?

    best of luck

  • cindywhitall
    Original Author
    11 years ago
    last modified: 9 years ago

    I think the indoor humidity is higher this winter, didn't get the dry sore throat I usually get in early winter when the heat starts up. I love being able to take a hot bath in my big tub after both boys just finished showers. And my son is glad he can shower without waiting after I've just filled the tub. The comfort was never really an issue before, except for the dryness. We keep the stat on 67 during the day, sometimes I'm home and it drops to 66 or 59.9 before it kicks it on I get chilly, but that would be with any system.

    I was happy when the news was reporting how busy the hvac companies were during last weeks cold, knowing that my furnace "should" not break down because it's new, vs the worry of my old system.

    It's 10 years to pay it off at $83/mth, but as I said, it's no interest so I don't care how it is as long as its doesn't die before then. Plus I have the carrier 10 year parts and labor.

    I'm pleased.

  • ionized_gw
    11 years ago
    last modified: 9 years ago

    For a better historical comparison look up the heating degree days for your area rather than using what ever temperature figure you were using.

    Air is not as dry? How did that happen, are the ducts or house better sealed now so you have less air leakage?

  • stoveguyy
    11 years ago
    last modified: 9 years ago

    Your old furnace was 90% eff so it was fairly new? How long have you owned ur house? Did u buy former furnace?

  • mike_home
    11 years ago
    last modified: 9 years ago

    Using one month of energy usage can be misleading. You need to look at the usage over a full year. You also can't look at the dollar amounts since the rates fluctuate each year.

    You keep your thermostat low in the winter. A good southern exposure on a sunny day could be enough to keep your house at 67 degrees when the sun is up. This will also affect the amount of gas usage.

    I don't see how the changes you made would decrease electricity use in the winter. There is something else going on to have caused the drop in electricity usage.

    Glad to hear you are happy with your new HVAC system.

  • energy_rater_la
    11 years ago
    last modified: 9 years ago

    I don't see how the changes you made would decrease electricity use in the winter.

    air sealing.

    comparing electric rates will help to track savings.
    once you have a full year of bills & rates, you'll
    have a better idea of savings.

    but enjoy what you've achieved.

    there are some things we are curious about though.

    best of luck

  • mike_home
    11 years ago
    last modified: 9 years ago

    Energy Rater,

    Can you elaborate on your response about air sealing?

  • energy_rater_la
    11 years ago
    last modified: 9 years ago

    sure Mike,
    I'm not a big fan of analogies, because I
    find that all too often people use them to
    misdirect. But, when I first got into this business
    this was the analogy that was the light bulb moment
    for me.
    It is easier to heat/cool a tight box than a leaky box.

    pretty simple isn't it.
    so take a minute to think about it.
    if the house is 2000 sq ft living space and
    has an air leakage measurement of 2000 cfm
    (cubic feet of air per minute) it is a pretty
    tight house. but if the air infiltration is
    4000 cfm...there is a lot of leakage.

    people often assume that their homes are tight
    with little air leakage. but until you test the
    house to measure the leakage & identify where
    the leaks are...its a wag.
    blower door testing shows where & how much leakage
    exists.
    our worst leakage site is to the attic.
    (not the front door!) attic temps are very extreme,
    and when this extreme temp air enters the house
    it brings dust, insulation particles & the attic temps
    that you then pay to condition.

    if you are only conditioning the air in the living
    space, it is easier, and affordable.
    sealing the air leakage has a very short roi, because the
    benefits are fast & long lasting.

    the next area that saves quickly, and improves
    indoor air quality is duct leakage.

    mastic sealing ductwork, plenum to equipment
    connections, return air chases & supply boxes
    to ceiling..(or walls or floors depending on
    the location of ducts)these things put the
    air you pay to condition into the house.
    otherwise this air leaks into unconditioned
    spaces. attic..crawlspace & basement.
    note mastic seal..not aeroseal, not duct tape or
    foil tape. mastic & mastic tape. you want
    something affordable that seals all leaks
    and lasts for a long time. mastic sealing
    has 30+ year life.

    I've been blower door testing & duct testing
    homes for a long time. it is highly unusual to
    find tight existing homes. same for ductwork.
    install, not air sealing is the focus of the
    trades people.
    slowly both builders & hvac installers are
    understanding..but it isn't common.

    until designers & architects start designing
    putting the ductwork inside the conditioned space
    at a time when it is the cheapest & easiest to do
    (design time) we will pay for putting our ducts
    & equipment in extreme areas.

    small things..recessed lights are a huge deal.
    not only for the amount of air they bring in
    from the attic, but the way they effect the indoor
    air quality.
    IC can lights are designed so that
    insulation can be installed next them.
    the housing of the IC can has holes.
    not only do these holes de-rate the R-value of the insulation, but they bring in attic air, and insulation particles.

    a simple thing is to only use ICAT recessed lights.
    (insulation contact Air Tight)
    retrofitting each IC
    light to air tight..costly &/or labor intensive.

    doing it right to start with..and realizing that
    efficiency costs are upfront..and long term is where
    we need to be investing.

    I'll step off my soap box now!
    if you need clarification, just post.

    best of luck

  • mike_home
    11 years ago
    last modified: 9 years ago

    Energy Rater,

    I agree with everything you stated. The part I am struggling with is a reduction of 135KwH of electricity use during the winter in a house which uses natural gas for fuel. I believe there is some savings due to the furnace blower running less now that the house is tighter. But I think that number is small in this situation.

  • ionized_gw
    11 years ago
    last modified: 9 years ago

    The electricity reduction is 13%. If we want to figure out if lower blower consumption is responsible, we should start with an estimate of what the blower part might be as a percentage of the total electric power consumption. If a blower uses 1000 W and it on a little less than half the time in the winter, that is 10 kWh/day or 300 kWh/month.

    135/300 is nearly half the energy for a blower if my numbers are right so that seems like the wrong way to go. Oh the other hand, if half the 135 is due to other factors, the blower could be a significant contributor.

    Is my number for the blower high, or run time too long? Please fix it if it is.

  • mike_home
    11 years ago
    last modified: 9 years ago

    I think Cindy's furnace has a multi speed 1HP motor which is the equivalent of 746W at full speed. Her old furnace probably had the same motor, but it was a single speed.

    Let's assume the average power between high and low stages is 500W. Cindy likes keeps the house cold (67 degrees), so I think a run time of 5 hours of day is generous.

    So the calculation is:
    500W * 5 hours * 30 days = 75KWHr per month total

    Now you have to estimate what the old furnace consumed. This gets to be hard since the old furnace was rated at 126K BTU at 90% vs. the new at 100K BTU at 96%. The old furnace may have used about the same electric power, but ran for shorter periods of time.

    In summary there may be a small about of savings of electricity in the winter, but I think it is a fraction of the total usage.

  • ionized_gw
    11 years ago
    last modified: 9 years ago

    In other words, the blower usage could not come close to saving that kind of power, especially since blower run time might have increased with a lower capacity furnace.

  • cindywhitall
    Original Author
    11 years ago
    last modified: 9 years ago

    Cavell, house will be 18 in may. I guess we were pioneers on the high efficiency. I think we are the only one, or one of very few in our neighborhood that upgraded. It cost us $800 to upgrade back then.

    Ionized. They air sealed the attic, all penetrations etc into attic and also did a little in the basement, around the 3 windows and the rim. Nothing dramatic done, just some orange goo on the spaces, and added about r19 blown cellulose in attic.

    Heating degree days were 851 per this bill, last January they were 859 for the month of Jan in southern NJ per www.ncdc.noaa.gov.

    the electric could be due to one week (on this bill)of LED Xmas light vs regular lights? Maybe 300 lights or so? That is possibly it. Imwouldnhave to check how many lights we replaced. New tv is 165 watts less power than old one, and it's on 5 hours day or more.

    This blower does seem to run lower at times, perhaps that is first stage. Don't know if it uses less electric in stage 1. We do have southern exposure in the front which helps.

    I'm just happy to see some savings! I am anxious to see how much did the air sealing and 16 seer ac makes.

  • david_cary
    11 years ago
    last modified: 9 years ago

    LED x-mas lights could be $10 savings for sure. Furnace efficiency could be $10. The furnace blower will use less electricity in stage I. I don't know your model but most newer motors are going to be more efficient to move the same amount of air.