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Heat pump heat/ac saving $

I currently have 2000sq ft 1 living floor and basement finished basement with a 1.5 ton heat pump & air handler heating and cooling the whole house. With life changes & new fixed income I need to cut my electrical cost. This summer I added two windo air-conditioning units to my living floor and saved approximately 50%. I would love to do the same thing during the winter so I’m looking for assistance on what I can add to my existing system that would be efficient. . I was wondering if I adding a tankless hot water system and adding a radiator in my existing air handler would be efficient.

I’ve installed air conditioners, heat pumps, and boilers before with the help of my friends and I’m looking for something that will cut electric bill if possible that I could do myself I modifying my existing system.


Right now I have a Goodman R12 1.5 ton heat pump with matching Goodman air handler.


I’m planning to upgrade the Acoil and heat pump and buying pre-charged lines in the future when I can afford it.


Comments

  • Hot_water_fan
    Hot_water_fan Member Posts: 2,037
    edited September 29

    I can’t imagine you’d save anything by doing this. That’s a small unit, so operating costs are small in relation to install costs. If it somehow did make sense to go dual fuel, just install a Goodman furnace that’s compatible with the heat pump. I see zero good reason to mess around with a tankless heater used as a central heating source and all the complexity that comes with hydronics.

    Do your math to compare $/mmbtu:

    gas: $/therm x 10/ COP.

    Heat pump: $/kwh x 293 /COP

  • pecmsg
    pecmsg Member Posts: 5,271

    I find it impossible to save 50% with a window unit.

  • Hot_water_fan
    Hot_water_fan Member Posts: 2,037
    edited September 29

    @pecmsg I think sometimes inefficiently cooling part of the house is better than efficiently cooling all of the house. Its apples and oranges of course. Also, without weather and rate adjustment 50% is missing all context.

    pecmsg
  • Bfwillie0116
    Bfwillie0116 Member Posts: 2

    Electric bill was $460 to cool the house and I was getting 52 degrees at the furthes register from the air handler and that was with the vents in the basement closed. I installed two small window units. It cooled the whole upstairs and my bill was under $150.

    Question about adding a furnace instead of just an air handler. Is there any efficient furnace that runs on electric only? If there is, would that be completely replacing my air handler or would it be an addition to?

    Also wanted to find out what the most efficient heat pump that is also reliable with today’s Freon.

    Your help is greatly appreciated. Thanks.

  • pecmsg
    pecmsg Member Posts: 5,271

    so you want to go straight electric.

  • Hot_water_fan
    Hot_water_fan Member Posts: 2,037
    edited September 29

    An electric furnace will cost 2-4x more to operate than a new heat pump and more than your existing one too. Its a dead end.

    There are plenty of high efficiency models out there today. Find a good installer and they can make it work.

  • DCContrarian
    DCContrarian Member Posts: 661

    From the description it sounds like the existing system is poorly installed. Window units shouldn't be more efficient. I'd be looking for ducts that are dumping into unconditioned space and the like.

    It may be that fixing the existing installation is as effective as a new system.

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,255

    I believe it is possible. That home is actually a 1000 Sq Ft rancher that cools perfectly with a 1.5 ton cooling system. The basement does not need cooling but I bet there is a good portion of that 1.5 ton of cooling migrating to the basement where it is not needed.  By turning off the 1.5 ton cooling unit and using a window shaker that might be only 3000 to 5000 BTU will cost a lot less than the central unit that is cooling unused spaces.  And the EER of the NEW window shakers can be higher than the EER of the central unit

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,255

    As far as adding a boiler… are you going to use natural gas or propane? or are you thinking of an electric boiler?

    As far as using an electric resistance heating furnace or boiler in place of a heat pump, that makes no sense at all. I believe that understanding the principle of how a heat pump works will clear things up.

    1 kW of Electricity can make 3412 BTU of heat when using electric resistance coils. the location of the coils doesn't matter that much. If they are in water then the water will get hot based on 3412 BTU per hour for each kW of electric applied. If they are in the ductwork, then they will add 3412 BTU of heat to the air that is passing by the resistance coils (the resistance coils are the wires that glow red in the toaster oven or electric stove)

    When you use a heat pump you have something called a Coefficient Of Performance (or COP). That means that when a heat pump uses the refrigerant cycle to put heat in the house, it is not making heat directly from the electricity. It is compressing the heat that is in the outside air and sending that heat inside. (think of putting the window air conditioner in the window backwards. The cold blows outside and the hot blows inside.)

    If you have a  COP of 2, it means that for every kW of electricity used you will get 6824 BTU of heat. WOW… twice as much heat from the same amount of electricity. A heat pump with a COP of 3 will make 3 times more heat from the same electricity. So if you remove the refrigerant cycle from the equation, then you are making the electricity less efficient. So use the heat pump. 

    If That is too expensive, then you need to seal up the ductwork, and maybe even seal up all the duct openings to the basement.  Your basement does not need as much heating or cooling as the top floor.  Depending on how much basement is below grade, (basement walls that are under ground) you may not need any cooling and you may even get away with only or 2 basement openings for heat, or even no openings at all for heat.


    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • pecmsg
    pecmsg Member Posts: 5,271

    Without knowing all the other details Here a 1000 Sq Ft home needs 9 - 12000 BTU/h fore cooling. That unit is 30% larger then needed.

  • hot_rod
    hot_rod Member Posts: 23,217

    Spend some time finding and sealing air leaks

    See if your local utility offers an energy audit

    An infrared scan and blower door test could show you where heat is escaping

    The best way yo lower energy cost is to use it more efficiently. Or use less

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    EdTheHeaterMan
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,255

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • DCContrarian
    DCContrarian Member Posts: 661

    Ducted or ductless? That's an incredibly common minisplit configuration.

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,255
    edited September 30

    i didn't ask about Mini-Split. Hell, I have installed ducted mini-split systems.

    I asked about UNITARY split systems! Who knows of one that is smaller than 1.5 ton? Just about every UNITARY system that most of us call "Central Air Conditioning" has a lineup like this:

    Smallest is 1.5 ton nominal and largest is 5 ton nominal

    So I'm asking again to @pecmsg and @DCContrarian and everyone else, does anyone make a smaller Unitary Split system in HP or AC?

    And does any of this information help to solve the original question? It is obvious that a MiniSplit price seems expensive for the OP. So comments like the ones @hot_rod posted are helpful, explaining COP are helpful, Debating the existing size, maybe not so much. Remember this is HeatingHelp.com.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • DCContrarian
    DCContrarian Member Posts: 661
    edited September 30

    How about this one:

    https://ashp.neep.org/#!/product/33271/7/25000/95/7500/0///0

  • GGross
    GGross Member Posts: 1,233
    edited September 30

    I know the website calls that a ducted unit but when I looked it up its a ductless.

    https://www.dcne.com/product/21s-12k-hp-dls-var-speed-115-1-performance-38maqb12r-1

    edit, OK I see carrier has a ducted fan coil this can attach to.

  • GGross
    GGross Member Posts: 1,233

    OP, if you have enough to spend on a tankless with hot water coil and the installation of that stuff, maybe its time to look at just upgrading the heat pump? you say you have an R12 heat pump, it's not going to be very efficient compared to current models. If you have R12 you will need to replace the coil though, which may be expensive depending on the air handler and install.

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,255
    edited September 30

    I believe that @DCContrarian has a good idea along with @GGross. There are more efficient systems that may be closer to the correct size. Although the one sited by @DCContrarian has been discontinued, I have looked at some of the new Rheem/Ruud air handlers that can be connected to inverter outdoor units that are smaller than the old one you have. And they work in colder weather before switching to auxiliary heat. I am truing to look up one for you but the AHRI directory is overloaded right now. Will try later.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?