Results 1 to 11 of 11
  1. #1
    Join Date
    May 2005
    Posts
    47
    I have a 58 year old house in Arlington, Va., with a 32 year old Carrier gas furnace and a 20 year old Carrier air conditioner.

    Both units have worked fine in the five years I've owned the house and have required no work apart from checkups and replacing a fuse on the A/C.

    My utility bills aren't outlandish considering the age of the equipment and that I've got old single-pane double hung windows and 2400 square feet (including finished basement). My electric bill peaks at $150 in the summer (compared to $50 in April/October) at $.09/KHW, and the gas bill peaks at $250 in the winter (compared to $30 in the summer for hot water and the stove) at $1.26/therm. I've got a programmable thermostat and set back to 60 at night in winter, though my wife is home with the little one so I don't set back during the day.

    The furnace is my primary concern. The latest tech to look at it said the heat exchanger is fine and didn't recommend replacement. But with a 2-year old in the house and another on the way sometime in the near future, I don't want to take chances with CO or with a winter outage.

    I'm thinking of the following system:

    12 SEER 2-stage A/C
    92% 2-stage/variable speed furnace.

    I'm sure the existing A/C can't be more than 6 SEER and the furnace 60% AFUE, so I'm getting a big boost there, but it looks like I'll get more bang for the buck saving money on utility bills by getting the 93% vs. the 80% rather than going higher above 12 SEER on the A/C.

    One other thought is a heat pump. I assume that equipment costs will be a bit lower, and I compared my gas/electric rates, and it appears as though the heat pump will be cheaper, at $.94 per therm output versus $1.35 per therm output from gas.

    Gas
    Input 1 therm
    Efficiency 93%
    Marginal $/Therm $1.26
    $/Therm Output $1.35

    Electric
    KHW/Therm 29.299
    Marginal $/KWH $0.09
    $/Therm Consumed $2.64
    HSPF 9.5
    COP 2.79
    $/Therm Output $0.94

    I hadn't really considered a heat pump until doing this calculation, but is seems as though it might be cheaper, although the gas would win for comfort.

    I'm replacing most of the windows this summer with high-efficiency Marvin windows.

    I just can't decide whether to replace stuff now before it breaks and the 13 SEER rule goes into effect, or wait it out and wait for failure. I'm also looking for thoughts on gas versus heat pump in my climate at my rates.

    Thanks for any advice.

  2. #2
    Join Date
    Apr 2003
    Location
    Eugene, Oregon
    Posts
    1,209
    First get the windows and insulation up to par then have a load calc done on the house. Heat pump systems will rely on electric resistant heat below 35 degrees, going dual fuel is an excellent way to go. May be a bit more initially however you get the less expensive heat pump in milder conditions then the gas heat as back up. Good luck
    Proud supporter of Springfield Millers and Oregon Ducks.

  3. #3
    Join Date
    May 2005
    Location
    Wilmington, NC
    Posts
    66
    I agree with millerman. Best system would be a 13 Seer Heat Pump Condensor with an 80% Variable Speed or 2 Stage Gas Furnace. Heat Pump would provide heat until the outdoor temp got below around 45 degrees. Esentially getting the best of both world. Electrical efficiency with the heat pump with out having the expensive auxiliary heater in the colder months. With the humidity in the NoVa area, the variable speed is key. If you didn't want Dual Fuel, at least go with a minimum 13 SEER AC with a Variable Speed 80% or 90%+ Furnace.

  4. #4
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    As stated above:

    Size the system for what's needed,when the windows and any other upgrades are done.This will save a lot and provide greater comfort then an oversized system!

  5. #5
    Join Date
    May 2005
    Posts
    47
    Should I do this now or wait for it to quit on a cold January night or a hot August afternoon? Can I try to get a few more years out of it?

    I figure that since I've done my research now, I'll be in a better spot to purchase on a moment's notice, but how quickly can companies to a changeout? A day? A week?

    Or should I just bite the bullet and do it soon, perhaps during the September/October lull (I missed the April lull, and A/C season is upon us here in DC).

  6. #6
    Join Date
    Jan 2005
    Posts
    44
    just a suggestion, check out Vernon heating and Cooling. They are in No. VA & MD. Best customer comfort warranty agreement I have ever seen. Good luck.

  7. #7
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    Originally posted by coldbud
    just a suggestion, check out Vernon heating and Cooling. They are in No. VA & MD. Best customer comfort warranty agreement I have ever seen. Good luck.
    Can we I/we get a copy of it??

  8. #8
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    Originally posted by kcb203
    Should I do this now or wait for it to quit on a cold January night or a hot August afternoon? Can I try to get a few more years out of it?

    I figure that since I've done my research now, I'll be in a better spot to purchase on a moment's notice, but how quickly can companies to a changeout? A day? A week?

    Or should I just bite the bullet and do it soon, perhaps during the September/October lull (I missed the April lull, and A/C season is upon us here in DC).

    Might take a week in the busy season,I'd do it this fall when mfrs have rebates,on top of the line stuff.

  9. #9
    Join Date
    Jan 2005
    Posts
    44
    Dash,
    If you were in the area, I would definitely reccommend your company. And that's just from reading your post.

  10. #10
    Join Date
    Apr 2003
    Location
    Eugene, Oregon
    Posts
    1,209
    Originally posted by kcb203
    Should I do this now or wait for it to quit on a cold January night or a hot August afternoon? Can I try to get a few more years out of it?

    I figure that since I've done my research now, I'll be in a better spot to purchase on a moment's notice, but how quickly can companies to a changeout? A day? A week?

    Or should I just bite the bullet and do it soon, perhaps during the September/October lull (I missed the April lull, and A/C season is upon us here in DC).
    32 years old for a furnace is prehistoric. You or anyone else for that matter can only guess at life expectancy. Knowing the added insulation and window factors will help in sizing the equipment properly. More than likely the old unit is oversized by a long shot. I would replace now and avoid the rush when everyone is waiting for replacement. It really makes for a crudy Christmas present. Michael
    Proud supporter of Springfield Millers and Oregon Ducks.

  11. #11
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    68,074
    I suggest you get a home improvement loan, and do it all at one shot.

    You'll be able to get the equipment sized for the new loads, and won't have to worry about the furnace breaking down on christmas eve.
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    How-to-apply-for-Professional

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

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