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jack_a_lope

Switching from propane to all-electric heat

Jack_A_Lope
9 years ago

Hello all,

We live in a rural area outside of Cincinnati, OH, and are looking at switching off of propane (natural gas isn't available out here) and onto an electric heat pump for our furnace (and replacing the a/c in the process). The primary reason is the high cost of propane (~$3+/gal), but both of us are wary of gas in the house and we'd love to get rid of the eyesore propane tank next to the house. While I am interested in geothermal, my sense is that it will be cost prohibitive, so we are mainly looking at traditional air-source heat pumps.

Our house is 16 years old and is a 2300 ft2 2-story with a ~1000 ft2 unfinished basement. There are registers going into the basement but most of them are closed off. I only leave one open to circulate air and to keep it warm enough in the winter. I'm not certain, but the propane furnace and air handler in the basement and the a/c unit outside all look to be pretty old, so I'm willing to guess they are the originals with the house.

In reading through these forums for a few weeks, it seems that the two top brands are Carrier and Trane (?). It sounds like Carrier's Infinity Greenspeed line is the most efficient (highest SEER/HSPF) available today and has a pretty quiet noise rating, but is also pricey. I like the efficiency, but for us the big cost savings is going to be the mere fact that we aren't on propane anymore, so I don't necessarily need top-of-the-line equipment to come out ahead. I've also read here about Trane having an electronic defrost on demand feature, which is spoken highly of, but I frankly do not understand the difference between that defrost method and a more standard method, and what the associated benefits would be. Can someone explain the electric defrost feature? As for relative brand quality/reliability, once one picks among the top tier brands, does the quality really boil down to the professionalism of the installer?

I have identified a few companies with good Angie's List ratings in our area, so I am going to start contacting them and getting the heating/cooling load calcs done to see how much of a system we need. I've learned a lot in reading this forum, and hopefully I can get some people's thoughts on my project as it moves forward. Thanks.

Comments (9)

  • tigerdunes
    9 years ago
    last modified: 9 years ago

    Jack

    New Heat Pump System

    Here is my general minimum spec sheet for new system.
    both outside and inside units should be replaced to have a properly matched system.

    15 SEER, 12.5+ EER, 9 HSPF
    best matching VS air handler
    full BTUs in both cooling and heating for your rated size
    R-410a refrigerant(same as Puron)
    scroll compressor preferred
    electronic demand defrost preferred
    thermostat with "dehumidify on demand" feature
    staged backup heat strips
    new and correctly sized refrigerant lineset
    10 yr warranty on parts and compressor

    you want a thorough inspection of your ductwork system. size, overall condition, supply and return lines, insulation qualities, leak test, etc.

    any hot/cold spot issues in your home should be addressed.

    My personal recommendation is Trane/AmStd, Rudd/Rheem, and Carrier/Bryant.

    Depending on your location, I would not purchase a new system that did not have electronic demand defrost.

    The Carrier Greenspeed holds their heating BTUs to a lower temp and yields higher HSPF heating efficiency than traditional air source heat pumps. Of course that comes with a price. You definitely should consider this system.

    Dealer should evaluate your electric service to make certain there is capacity to handle the strip heat. You want the strip heat, outside HP condenser, and var speed air handler on separate circuits. Modification/upgrade to your electric service may be necessary.

    There are 2 methods of defrost for heat pumps. Time/temp and electronic demand defrost. I suggest you let Google be your friend as there are many articles on this subject. Time/temp is a cheap method and you get defrost calls kwhether they are needed or not. EDD eliminates/reduces unnecessary defrost calls which are both nuisance and expensive plus the wear and tear on the condenser itself. EDD uses both hardware and software for this feature. It is well worth it.

    By getting rid of propane, you may actually see a payback on a new HP system.

    IMO

  • jakethewonderdog
    9 years ago
    last modified: 9 years ago

    Different but related: What is your water heater (my guess is standard electric since you are getting rid of propane). You can save about $260 a year if you switch to a hybrid electric heater.

  • Jack_A_Lope
    Original Author
    9 years ago
    last modified: 9 years ago

    Thanks for the replies.

    Had two highly rated (Angies List) HVAC installers come out today, one specializing in Trane and the other Carrier. Both were very nice, took measurements all over the house and calculated required heat load. Both identified that my electrical panel had insufficient breakers available, so they would have to add a sub-panel. Both noticed that an upstairs return setup was poorly designed (and it is in an area of the house that is very tough to keep cool when it gets warm). Carrier guy seemed more knowledgeable about this issue, though maybe he just explained it more to me.

    Trane guy calculated the need for a 3 ton system, and said it would take a day or two to put together a good-better-best bid on the standard heat pump, and several more for a bid on Geothermal. I don't have high hopes for geo making $-sence, but I'd just like to get an actual quote as opposed to going off of internet rules of thumb, to be sure as to whether it's even worth considering.

    The Carrier guy calculated ~40kBTU/h need, so a little over 3 ton. He sat down with us and talked in detail about what feature and equipment would be best for us. He used Carrier's 'Right-$' operating cost calculator to estimate the relative operating cost difference between the units he quoted. He did this all during the initial visit, which was nice. Below are the options they quoted.

    Baseline:
    Outside unit: 25HBC342A0030
    Air handler: FB4CNF042
    SEER: 13
    HSPF: 7.8
    Cost: $7200

    Midrange:
    Outside unit: 25HNB636A0030
    Air handler: FV4CNB006
    SEER: 17
    HSPF: 9.5
    Cost: $10000
    Estimated annual cost savings over 'Baseline': $202

    Top of the line:
    Outside unit: 25VNA048A0030
    Air handler: FE4ANB005++UI (not sure if the ++UI is part of the #)
    SEER: 17.9
    HSPF: 11.45
    Cost: $12700
    Estimated annual cost savings over 'Baseline': $522
    *The Greenspeed option did not come in half-ton increments, so he spec'ed a 4 ton unit, but said with the variable speed features it could essentially run like a 3.5 ton unit. Made sense to me.

    All options included installation and removal of old equipment, new line set, whole house humidifier, small necessary ductwork mods to connect new system, staged resistance back-up heat strips (unsure what wattage) wi-fi capable (we don't care about the wi-fi bit) programmable thermostat and 10 year parts/labor warranty OR with the top level Greenspeed option, the Carrier Infinity controller and 15 year parts/labor warranty.

    We really appreciated the time the Carrier guy spent with us. We liked the two higher-end options due to being quieter and having the ability to dehumidify on demand, but they are a lot more up-front cost than the basic unit. The basic unit will no doubt be a little quieter than our current 16 year old A/C and furnace blower. The biggest cost savings for us is moving off of propane. I'm estimating ~$1500 per winter savings due to switching to the 'Baseline' heat pump, with perhaps another $300 in winter savings going from the 'Baseline' to the Greenspeed model (which is roughly in line with their $522 annual savings estimate for the whole year). Economically it's tough to justify another ~$3k or ~$5.5k when ~80% of my potential total savings are realized with the cheapest setup. Perhaps I will see if I can get the higher end variable speed air handle with the cheapest outside unit.

    Lastly, on the water heater, we are planning on switching it over to a high performance electric model. The Carrier installer will also apparently replace water heaters, though I need to wait to hear from them what their install cost is for a unit I buy myself ... which matters b/c I work for GE and get a pretty hefty discounts on their appliances, and they make high efficiency water heaters (http://www.geappliances.com/heat-pump-hot-water-heater/). I don't really care that it is from GE, aside from the discount, but unless I suddenly hear that their high performance electric water heaters are total junk there's a strong financial incentive for me to buy the unit myself.

    I'll update when I hear the bids from the Trane dealer. Thanks for any input folks feel like providing.

  • tigerdunes
    9 years ago
    last modified: 9 years ago

    Prices include the electric service modification/upgrade?

    Can't say I understand the sizing of the good-better-best quotes. 3 1/2 ton, 3 ton, 4 ton. In fact I don't care for that type of salesmanship unless you requested it.

    You need another quote from a Carrier or sister company Bryant dealer.

    IMO

    This post was edited by tigerdunes on Wed, Oct 1, 14 at 7:10

  • Jack_A_Lope
    Original Author
    9 years ago
    last modified: 9 years ago

    To clarify, while we did request a 'good/better/best' type of quote, it was more in reference to general technology level of the equipment as opposed to the sizing ... i.e. we did not say "show me a 3/3.5/4 ton comparison".

    Now, as to WHY there was such a difference in equipment size, I guess I can't say for certain, but here are a few thoughts. He calc'ed our heating needs at 39k BTU/h, so in their product offering book he flips to the 42k BTU/h page. That page has several heat pumps and three levels of air handler tech. We mix and matched a couple options, and then he put them in their Carrier 'Operating Cost Estimate 2.0' s/w (http://sagoro.wrightsoft.com/Carrier/Default.aspx), which I believe dictated the actual model numbers of the equipment based on the inputs to the code. I've played with that site some and have found that by changing our cooling needs from 39k BTU/h to 37k, the site kicks all the equipment down to 36k BTU/h equipment, as opposed to the original smattering of 3/3.5/4 ton equipment. So, my read is that he wasn't purposefully trying to give us equipment options sized differently, but with our heating needs being just over 3 ton and at the lower end of the 4 ton range (and apparently the Greenspeed line does not come in half-ton models), that's how their software spit out the model numbers. Just my speculation.

    However, regardless of the appropriateness of the original equipment selection, this begs the question as to whether we can get by with 3 ton vs 4 ton equipment, given our 39k assessed needs. Looking at the AHRI site, the 'baseline' and 'midrange' options had similar 17F heating capacity of ~22k BTU/h (despite being 42k and 36k cooling & 47F heating capacity, respectively). I picked out a 3 ton Greenspeed model, and it's cooling and 47F heating capacity was indeed ~36k BTU/m but it holds its cold performance so well that at 17F it was 32k (vs 22k for the others, +40%). My current 16 year old A/C is 3 ton, and actually does a pretty good job of keeping the house cool, with the exception of a 2nd floor loft at the top of an open stairwell whose lone return register appears to not be drawing air well and which also has a large westerly facing window. So I'm wondering if a 3 ton Greenspeed system (25VNA036A / FE4ANB006) makes more sense for my situation, saving some money on that system's up-front cost? The lower end units probably do need to be sized up around the 40k range, since their capacity drops off so much at low temps.

    Lastly, yes, electrical service modification was included in the prices posted earlier. Thanks for the feedback!

  • Jack_A_Lope
    Original Author
    9 years ago
    last modified: 9 years ago

    Been a while since my last update. I posed my questions above to the Carrier dealer, and he said that the 'mid range' system's size should have been 3.5 and that he would update the model number, but he did not recommend going down the the 3 ton size on the Greenspeed. I can see the logic of slightly oversizing the Greenspeed units, since they can run efficiently at part capacity with their variable speed compressor/blower. In any event, he offered to give me the 4 ton Greenspeed system at the 3 ton price, but the savings was only ~$400, which still left that system costing $12k+, which was just more than we are willing to spend.

    We also got the Trane bids in several days ago. Apparently Trane has this weird rebate offer that is a drawing, where you can 'win' $50, 75, 100, 150 per SEER unit off your system. Apparently everyone gets at least $50/SEER, so I'll assume I 'win' $75/SEER. The prices shown below are in BEFORE .. AFTER format. I really don't like that kind of rebate, because you literally don't know what the final price will be.

    Low-end system:
    Outside unit: 4TWX5046B1
    Air handler: TAM7AOB36H31
    SEER: 15
    HSPF: 9.25
    Price: $10900 .. $9100

    Mid-range:
    Outside unit: 4TWX8036A1
    Air handler: TAM7AOB36A1
    SEER: 18
    HSPF: 10.0
    Price: $11700 .. $9800

    High-end:
    Outside unit: 4TWV0036A1
    Air handler: TAM8COC36V31
    SEER: 19.75
    HSPF: 10.0
    Price: $13900 .. $11800

    Prices include essentially everything the Carrier installer's offer did.

    I think the high-end from either brand is out of our price range. Their projected annual savings over the next model down just don't justify the price difference. We are currently leaning towards the mid-range systems, because they do provide improved performance (and less noise, at least with the Carrier line). Those two systems are essentially the same price. All things being equal I think we liked the Carrier installer a little more, but we're still debating which way to go.

    Feedback is welcome. Hopefully some casual readers gain some knowledge from this post, as I did when I read prior posts. Thanks.

  • tigerdunes
    9 years ago
    last modified: 9 years ago

    You need to get sized correctly.

    What you refer to as low end system appears to be a 4 ton condenser while the mid and upper end systems are 3 ton.

    What size is current AC condenser?

    Has your ductwork system been inspected?

    What size heat strip? Did you request that it be staged? Anything about a filter cabinet? What thermostat was quoted? All of these are not insignificant details.

    IMO

  • countryboymo
    9 years ago
    last modified: 9 years ago

    I know your Propain and the volatility is brutal but after having electric heat compared to gas it takes getting used to. I have all electric heat pump/strip and have installed a pellet stove in the basement to also supplement the heat pump and be able to weather a extended outage with small generator.

    If you own the tank I would consider a dual fuel heat pump propane setup and if the tank would be big enough to buy once a year. Of course I have also heard stories about people getting charged for not buying on a schedule so everyone no one can store enough to ride out the stupid prices.

    Rural area? Is there a pond nearby that could be used for a closed loop geothermal system? This would be the best deal by far.

    Maybe all electric isn't such a bad idea after thinking about the volatility and games that propain companies sometimes play.

    I also know someone who had anatural gas well drilled near me and went all gas, water heat drier and furnace and bought a pump for cng and converted both his vehicles to run on it. He had testing done to run a 20-30kw microturbine and go back to all electric and sell to the utility and probably could but don't want to chance exhausting his supply prematurely even though the test was really good he is going to run a few more years and retest and see what impact he has on it as is.

    Getting windy but my point to you and everyone else is don't stop thinking outside of the box that most everyone else sits in.

  • kath1750
    9 years ago
    last modified: 9 years ago

    Your in a cold area. My experience is heat pumps never get you warm in cold climates. I like the idea of dual system. Heat pump until set temp outside then propane heat kicks in to keep you warm. If I had the money would do just that here in NC.