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  1. #14
    Join Date
    Mar 2008
    Location
    Near Charlotte NC
    Posts
    51
    Quote Originally Posted by beenthere View Post
    Not to push a hybird, or heat pump only system.

    But. HP's today provide more heat then the older ones did.
    Also, the Infinity HP, with Infinity control will slow the blower so you don't get the cold air out the registers like older HP's did.

    If the main area of the second floor is going to be kept cooler,(62 to 64) the aux heat won't be needed much.
    As a zoned system, when only one zone is calling, even when its 20 outside, the HP may not need the aux except when in defrost.

    Compare your gas an electric rates to find which will provide the most heat for you buck.
    Thx Beenthere.. funny, cause as I'm writing this my 12 year old is in the kitchen with a stool parked next to a register and enjoying the warm gas air blowing over him!

    And thx for the additional HP info.. I've been away from them for 16 years now and hated the one I had in my other home ( typical reasons, cold air coming form vents, strips kicking in fairly often and so on ). Is great to hear that things have changed!

    My dumb question is I'm assuming a HP alone would be cheaper than a AC + gas furnace option but then as I don't know what I'm talking about, I'll just ask.

    My electric rates here are quite reasonable ( about 9 cents per kwh.. wish I were buying power from my own company as it would be under 8 cents per kwh.. my shameless plug for nuclear power.. still cheap even with the overregulation and no greenhouse gases, and we release much LESS radiation ( in the form of inert noble gases ) to the environment than a similar sized coal plant ). Gas is $1.36 per ccf, or 1.33 per therm .

    Is certainly worth considering!

  2. #15
    Join Date
    Mar 2006
    Location
    The South
    Posts
    2,240
    jadvis

    Today's heat pumps are as different as night and day to yesteryears.

    Crunch the numbers with attached fuel comparison calculator.

    IMO


    http://www.warmair.com/html/fuel_cost_comparisons.htm

  3. #16
    Join Date
    Mar 2008
    Location
    Near Charlotte NC
    Posts
    51
    Quote Originally Posted by m-cooling View Post
    or your contractor could use a zone system.
    m-cooling.. thanks I had at one time considered a stand alone system for the bonus room but the layout of the house, etc would make that a real challenge. The last contractor to stop by, the one proposing a carrier infinity system, was quoting a zones system for the bonus room ( upstairs would have 2 zones ). He did NOT quote a non zoned system.

    The detail I need to get from him is how he designs hiw ductwork. Does he use the ole rule of thumb approach, does he use software to calculate heat loads, duct sizes, etc, and so on.

    His quote included new ductwork, a carrier infinity 80% dual stage furnace, a 3 ton carrier coils, and a 3 ton carrier infinity dual stage 16 SEER AC unit. HIs price was certainly not the cheapest nor was it the most expensive. He quoted me another system , zoned, using Trane, and it was significantly more than the Carrier Infinity system ( similar SEER ratings ). He also included 2 Infinity thermostats ( Infinity Control ). A quote I received from a different company using a single stage AC unit, 13 SEER, as ingle stage gas furnace ( 80% ), plus new dutc was actually 25% more than the Carrier quote.

    You guys have all convinced me that the zoned approach will yield the best results I can hope for short of a separate system. I had given thought initially to just accepting a manual balance approach and optimizing as best I could using a simple system plus new ductwork since it no doubt would be a vast improvement over where we are now. It would also be about 32% cheaper than the Carrier Infinity zoned system quote.

    When I replace my downstairs unit I know I will not go as high end as the upstairs because the present system is doing "ok" down there. It's a smaller area and has fewer challenges. That leads me to going to the zoned system approach once I find an installer who will give me warm fuzzy feelings on the ventilation duct design.

    Price does enter the equation and it's hard at times not to want the Mercedes when perhaps a VW Passat will do, especially if one is currently driving an old beat up Yugo! Like all families, we have to balance our budget as the money we bring in all goes to the same budget. We've already put our kitchen remodel on hold due to the rising costs asscoiated with it and all the expenditures we've already taken on. I know once this new system is installed we will be simply amazed at the difference as long as we take the proper precautions to get a quality design done.

    Everyone here is very much helping with that. After reading all the replies I have bene able to totaly eliminate one contractor that I was actually at one time wanting to consider because I liked his hybrid system approach. He would have installed some great compionents into a crappy vent system and without zoning... I would have been miserable. I would have placed a BMW 5 series M5 engine into a yugo chasis.

    With the price quoted ( not being cheap mind you in any way ) and the components/zoned apprach , the Carrier infinity quote is now in high regard, assuming he will do the proper calculations for the new duct.

    So many considerations but the hardest one of all is finding the right contractor!! Course one guy who came by wanted to keep the existing furnace, " run some bigger duct to the bonus room " and then said he could do lots with the rest of the duct work as is... was definitely an inexpensive quote compared to the rest but not exactly a reassuring one!

  4. #17
    Join Date
    Jan 2004
    Location
    PA
    Posts
    68,797
    In reality, about the same install cost, since you would need to have a new electric feed run to the attic to carry the current for the strip heaters.

    At your rates, an 80% gas furnace is cheap then the aux resistance heaters are to operate.
    On the other hand, BTU to BTU, as long as the heat pumps COP is 1.6 or above, its cheaper then an 80% NG furnace. And as long as its above 1.8 COP, its cheaper then a 90% NG furnace.

    Most high efficiency heat pumps have a COP of 1.5+ even at 0*F outside temps.
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  5. #18
    Join Date
    Sep 2006
    Posts
    1,253
    Mr. Davis,

    I purchased my home in the summer of 2005. I immediately realized I had something wrong with my second floor system (same as you one system per floor). Temp difference between the front part of the home (on that floor) and the back was about 10*. And the 3-ton heat pump for that floor was running constantly while the master bedroom was hot and muggy.

    Called virtually every contractor I could find (rural area not a lot to choose from) to come evaluate the situation and make recommendations. Essentially, I heard the same from all of them. They didn't know what was wrong with my system, but they could fix it by installing their system. There was absolutely no testing done. The closest was one guy held his hand in front of a register in the master bed room and said that there was "some" air coming out so the ducts were fine - I just needed his new equipment. Several said that my heat pump was not efficient enough and that new high SEER equipment would take care of the problem. What a load of crap.

    My BS meter was going off big time. The contractors were selling not analyzing and coming up with a well founded strategy to resolve the issues. I found this forum and started reading everything I could find. The big issue I discovered was the industry, as a whole, does not understand air flow and how to test and measure it. Now, that does not, at all, mean that no one knows. The pros on this board preach it because it is where a lot of the problems are. Find a pro that knows.

    My system essentially needed more return air (very common problem) and balance dampers (another very common problem) on the supply branches to balance the air and get it to where it needs to be. Now, during the summer, there is not more that 0.5 degree difference between rooms.

    Doing the Manual J calculation room by room will provide you with the required air flow room by room. With this data the testing can begin. Measure the air flow, measure the resistance to it flowing (known as ESP External Static Pressure), balance the air flow to each room, measure the amount of cooling being delivered by your system, and fully analyze the performance of your system to determine what needs to be done to correct it. If there is leak find it and fix it. If there are other problems, weight repair against replacement. Often the repair is not that big of a deal.

    Hopefully you can find a good pro that can do all that needs to be done. Otherwise you may have to do as I have and get yourself educated enough to act as a general contractor and hire companies to perform all of these items. I detail exactly what I want done and spec it out for them. Review the work and pay when it is delivered as spec'ed. The reduction in my utility cost have virtually paid for all the work I have had done so far. And the home is so much more comfortable.

    One other issue on your bonus room. Many of these that are over garages have knee walls. For some reason those short walls do not get the same level of insulation that the roof area of the bonus room gets. The walls will have R13 when it is exposed to the same heat as the rest of the attic area. Big source of heat in the summer.

    The next issue is the way the insulation is installed in the floor area which is the ceiling of the garage. Often, the insulation is installed so that it is against the ceiling of the garage. This leaves a gap between the bottom of the floor and the insulation. If there is any way for unconditioned attic air to migrate through that gap, then the floor of the room is effectively not insulated. This gap can often be seen where the sub-floor stops at the knee wall.

    Finally, the bonus room is about a quarter of your total square footage on the second floor (may be more when compared on a total volume basis) and if the system was not sized for it to begin with, then the whole area is going to suffer by putting that much more load on it. Either download the load calc program from this site (I did, it is well worth it) or pay to have a full run done.

    Good luck and continue to listen to the pros on this board - they are good and will get you going in the direction you need to go, which is sometimes different then when someone is trying to sell you something.

  6. #19
    Join Date
    Mar 2008
    Location
    Near Charlotte NC
    Posts
    51
    Quote Originally Posted by tigerdunes View Post
    jadvis

    Today's heat pumps are as different as night and day to yesteryears.

    Crunch the numbers with attached fuel comparison calculator.

    IMO


    http://www.warmair.com/html/fuel_cost_comparisons.htm
    Tiger,

    Thx.. I didn't know what value to use for the heat pump COP so I left it at 1.7. In doing that, the calculator showed cost for 100,000 btu of gas would be $1.65 and the heat pump at $1.55, which is about 6.4% more for the gas furnace assuming an 80% efficiency. I'm also assuming if the strip heating of the heat pump is used very often the cost of the heat pump would also increase. if so, it would appear the cost between the 2 is fairly similar for me unless I've missed something. Thx for the link!

  7. #20
    Join Date
    Mar 2008
    Location
    Near Charlotte NC
    Posts
    51
    Quote Originally Posted by beenthere View Post
    In reality, about the same install cost, since you would need to have a new electric feed run to the attic to carry the current for the strip heaters.

    At your rates, an 80% gas furnace is cheap then the aux resistance heaters are to operate.
    On the other hand, BTU to BTU, as long as the heat pumps COP is 1.6 or above, its cheaper then an 80% NG furnace. And as long as its above 1.8 COP, its cheaper then a 90% NG furnace.

    Most high efficiency heat pumps have a COP of 1.5+ even at 0*F outside temps.
    Thx Beenthere. It sounds like the heat pump alone would take some effort since I don't have any spare panels in my breaker box, though it is certainly doable. The heat pump no doubt would do a good job based on what you guys have provided though I'm not sure it's going to be a huge difference overall. If it's a toMAYto versus toMAHto thing, I'd prefer to keep the install as simple as possible.

    It does though sound like heat pumps have come a LONG way since the days of old!

  8. #21
    Join Date
    Mar 2006
    Location
    The South
    Posts
    2,240
    jdavis

    For a Carrier Infinity 16 HP, you should use a COP of 2.75 and that number is on the conservative side. This should give you a very nice savings over nat gas.

    IMO

  9. #22
    Join Date
    Mar 2008
    Location
    Near Charlotte NC
    Posts
    51
    Quote Originally Posted by mchild View Post
    Mr. Davis,

    I purchased my home in the summer of 2005. I immediately realized I had something wrong with my second floor system (same as you one system per floor). Temp difference between the front part of the home (on that floor) and the back was about 10*. And the 3-ton heat pump for that floor was running constantly while the master bedroom was hot and muggy.

    Called virtually every contractor I could find (rural area not a lot to choose from) to come evaluate the situation and make recommendations. Essentially, I heard the same from all of them. They didn't know what was wrong with my system, but they could fix it by installing their system. There was absolutely no testing done. The closest was one guy held his hand in front of a register in the master bed room and said that there was "some" air coming out so the ducts were fine - I just needed his new equipment. Several said that my heat pump was not efficient enough and that new high SEER equipment would take care of the problem. What a load of crap.

    My BS meter was going off big time. The contractors were selling not analyzing and coming up with a well founded strategy to resolve the issues. I found this forum and started reading everything I could find. The big issue I discovered was the industry, as a whole, does not understand air flow and how to test and measure it. Now, that does not, at all, mean that no one knows. The pros on this board preach it because it is where a lot of the problems are. Find a pro that knows.

    My system essentially needed more return air (very common problem) and balance dampers (another very common problem) on the supply branches to balance the air and get it to where it needs to be. Now, during the summer, there is not more that 0.5 degree difference between rooms.

    Doing the Manual J calculation room by room will provide you with the required air flow room by room. With this data the testing can begin. Measure the air flow, measure the resistance to it flowing (known as ESP External Static Pressure), balance the air flow to each room, measure the amount of cooling being delivered by your system, and fully analyze the performance of your system to determine what needs to be done to correct it. If there is leak find it and fix it. If there are other problems, weight repair against replacement. Often the repair is not that big of a deal.

    Hopefully you can find a good pro that can do all that needs to be done. Otherwise you may have to do as I have and get yourself educated enough to act as a general contractor and hire companies to perform all of these items. I detail exactly what I want done and spec it out for them. Review the work and pay when it is delivered as spec'ed. The reduction in my utility cost have virtually paid for all the work I have had done so far. And the home is so much more comfortable.

    One other issue on your bonus room. Many of these that are over garages have knee walls. For some reason those short walls do not get the same level of insulation that the roof area of the bonus room gets. The walls will have R13 when it is exposed to the same heat as the rest of the attic area. Big source of heat in the summer.

    The next issue is the way the insulation is installed in the floor area which is the ceiling of the garage. Often, the insulation is installed so that it is against the ceiling of the garage. This leaves a gap between the bottom of the floor and the insulation. If there is any way for unconditioned attic air to migrate through that gap, then the floor of the room is effectively not insulated. This gap can often be seen where the sub-floor stops at the knee wall.

    Finally, the bonus room is about a quarter of your total square footage on the second floor (may be more when compared on a total volume basis) and if the system was not sized for it to begin with, then the whole area is going to suffer by putting that much more load on it. Either download the load calc program from this site (I did, it is well worth it) or pay to have a full run done.

    Good luck and continue to listen to the pros on this board - they are good and will get you going in the direction you need to go, which is sometimes different then when someone is trying to sell you something.
    Mchild.. thanks for the reply and all the information as well as your success story. At one point I had given thought to simply fixing whatever problems are in the duct system and then see how it plays out. That said, I think there are other problems with the current system such as the mismatched generic coils ( which also appear to have a small feon leak ) that will need to be fixed.

    That said, on the 17th I am supposed to be having the vent system tested for leaks, home leakage rates and so on. I agree totally, though, that when a person is selling equipment, often you get little useful information other than to buy new.

    I also recognize there are some good professionals out there who are ethical and also very good at what they do. In the Charlotte NC area we have hundreds of HVAC contractors and in recent times new construction has kept them all hopping. That is changing now and perhaps we are seeing as urplus of installers. Is just hard to find a good one though hopefully I'm getting there.

    Ther eis no way I have the time to do a Gen Contractor type of job here.. I'd be divorced before the install was complete lol Hopefully I'll be able to post a similar success story soon! Thx again

  10. #23
    Join Date
    Mar 2008
    Location
    Near Charlotte NC
    Posts
    51
    Quote Originally Posted by tigerdunes View Post
    jdavis

    For a Carrier Infinity 16 HP, you should use a COP of 2.75 and that number is on the conservative side. This should give you a very nice savings over nat gas.

    IMO
    Tiger,

    Thanks! Savings now is very easy to see ( $0.96 versus $1.65 ). Hmmmmmmm very interesting!

  11. #24
    Join Date
    Jan 2004
    Location
    PA
    Posts
    68,797
    Your contractor can probaly do a savings estimate for you using the bin data for your area.
    Using the bin data, he can enter the COP for each temp range.
    The colder it is outside, the lower the COP. And of course the warmer outside, the higher the COP.

    Be gentle on him when you approach him with all these questions and suggestions.
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  12. #25
    Join Date
    Sep 2006
    Posts
    1,253
    Quote Originally Posted by jdavis37 View Post
    Mchild.. thanks for the reply and all the information as well as your success story. At one point I had given thought to simply fixing whatever problems are in the duct system and then see how it plays out. That said, I think there are other problems with the current system such as the mismatched generic coils ( which also appear to have a small feon leak ) that will need to be fixed.

    That said, on the 17th I am supposed to be having the vent system tested for leaks, home leakage rates and so on. I agree totally, though, that when a person is selling equipment, often you get little useful information other than to buy new.

    I also recognize there are some good professionals out there who are ethical and also very good at what they do. In the Charlotte NC area we have hundreds of HVAC contractors and in recent times new construction has kept them all hopping. That is changing now and perhaps we are seeing as urplus of installers. Is just hard to find a good one though hopefully I'm getting there.

    Ther eis no way I have the time to do a Gen Contractor type of job here.. I'd be divorced before the install was complete lol Hopefully I'll be able to post a similar success story soon! Thx again
    Acting as your own GC is a last resort. Get a local contractor that is not just interested in selling that can handle all the issues including air flow and you will be happy. Since you are in a rather large metro areas you should be able to find someone. You may get a referral from someone on this board.

  13. #26
    Join Date
    Mar 2008
    Location
    Near Charlotte NC
    Posts
    51
    Quote Originally Posted by mchild View Post
    Acting as your own GC is a last resort. Get a local contractor that is not just interested in selling that can handle all the issues including air flow and you will be happy. Since you are in a rather large metro areas you should be able to find someone. You may get a referral from someone on this board.
    mchild,

    One would *think* in a larger market segment that it would be easier to find a real expert but thus far it seems as though it just draws more non experts, especially given how booming the new housing market has been up until just recently. And of course many new home builders are not worried about doing it precisely right, just right enough to make it pass inspection.

    I'm actually about 20 miles north of Charlotte but anyone in the Charlotte area would work so if ther eis knowledge of anyone that fits the bill I'd welcome the info. Hopefully, the Carrier quote will trun inot a full load calc in terms of room by room and I'll be set. Not holding my breath but do hope so!

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