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Window Unit Heat Pumps

kieran973 | Posted in General Questions on

Does anyone have any experience with window unit heat pumps? Frigidaire and Amana make a few models, many of them 115 volt units,  which range from 7,000 – 14,000 btuh, with COPs between 2.6 and 2.8. I have no idea at what ambient temp they achieve these outputs and COPs – the specs don’t say. But the units cost roughly $1,000 – $1,500, and there’s no installation costs, you just plug them in, which makes them cheaper than mini-splits (though granted you may need a dedicated 15 or 20 amp circuit for some of the units). For those who have used them: are they loud? Do they work down to 20 degrees F or so? Is it possible to get a good enough seal (well insulated and air sealed) with the window unit in cold winter temps?  These would be for a small upstairs space of three 100-150 sq ft bedrooms. Climate zone 5, 99% design temp 11F, total heat load of entire upstairs at design temp is 11,500 btuh. So I figure one of these units could actually heat the entire upstairs with all the doors open. There will also be backup electric resistance baseboard heat, but buying one of these window units would save about $5,000, because the alternative would be to put in a ductless Mitsubishi hyper heat wall unit in the upstairs hall. We’re already doing two ductless hyper heat wall units downstairs. Ducting is not an option on either level at this time, for different reasons. Thanks.

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Replies

  1. aunsafe2015 | | #1

    I can't answer your question but just wanted to chime in that I'm also interested in hearing more information about the window unit heat pumps.

  2. brian_wiley | | #2

    Do you happen to have a link to a model? From the models I found it was difficult to tell if they were true heat pumps, or just an air conditioner married to a small electric heat strip.

    1. Expert Member
      MALCOLM TAYLOR | | #7

      Kieran973,

      Keep an eye on the code requirements for egress from bedrooms. The picture in your link, where the unit blocks the operable portion of the window, looks like a violation to me.

      1. kieran973 | | #10

        Thanks. The room it would go in actually has four windows, so I don’t think egress would be an issue.

  3. kieran973 | | #4
  4. walta100 | | #5

    If you are set on a window shaker consider a Midea unit with varable speed compressor and an innovative design. More or less a mini split in a window unit.

    If it is about the install cost consider a PTAC heat pump like most Hotel rooms use the look is much better and you still get to look out your window.

    Walta

    1. brian_wiley | | #6

      Walta,

      Do you know if they’ve added a heating function to those Midea units? I happened to look at those last week on an unrelated project and couldn’t find one that actually provided heat. I’d heard rumors that they were in development, but nothing since that.

  5. walta100 | | #8

    I did not look for a model with heating.

    Walta

  6. kyle_r | | #9

    If you have a fairly tight and we’ll insulated home you may not need any heat upstairs especially if you have an open stairwell. Is AC a concern?

    1. kieran973 | | #11

      House is old and leaky, but I’m working on getting some quality air sealing as well as some more insulation done. AC is not a primary concern right now - the main thing I’m trying to do is heat the upstairs for a few years. We’re going to finish off the attic eventually, at which point we may try to put an air handler up there (once the attic is conditioned and the renovation is done) with some ductwork down to the second floor. But I don’t want to put hvac equipment and duct work up there now, so for the second floor we’re limited to either: one $5-6K minisplit with a COP of 4.23 in the upstairs hall; one $600 window unit heat pump from Walmart with a COP of 2.8; oversizing the downstairs minisplits slightly and hoping enough heat travels up the stairs; or resistance heat from the baseboard radiators.

      1. kyle_r | | #16

        If you have baseboards already installed, I would use those no question. Especially considering it’s somewhat temporary. I would see how cold the bedrooms get without any heat first. Then turn on the baseboard if you get too cold.

        1. kieran973 | | #20

          I do have hydronic radiators in the baseboards right now, but they’re currently heated by our gas boiler. The post-mini-split plan would be to then replace this gas boiler with an electric boiler (rather than rip out all the hydronic baseboards only to replace them with standard electric resistance baseboards). But the plan would be for these baseboard to only serve as auxiliary heat for cold days beyond the 99% design temp (11F). But I think you’re right that before adding anything to the second floor, I could see how these bedrooms feel with just the first floor mini-splits and then go from there….

          1. kyle_r | | #23

            If you are putting in cold climate or hyper heat units you won’t need a backup system in Zone 5. Not sure it makes sense to to keep hydronic baseboard if you have it and it’s in working condition. I also would not replace your boiler until it dies and then at that point evaluate if you really need to replace it for backup heat. You might need an electrical service/panel upgrade for an electric boiler. What is you plan for domestic hot water?

  7. brian_wiley | | #12

    If heating is the primary concern, have you considered something like the Envi wall-mounted heaters? They’re sized to do about 150 sq feet, and only draw 500 watts/4.2 amps. They’re also relatively cool to the touch if kids are a concern.

    Envi High-Efficiency Whole Room 120v Plug-In Electric Panel Wall Heater https://www.amazon.com/dp/B086N4MJ2M/ref=cm_sw_r_cp_api_glt_fabc_0K9R75RW045KJ2DQ67F6?_encoding=UTF8&psc=1

    1. kieran973 | | #21

      I thought about those but they get some mixed customer reviews (Amazon, etc) - bad smells, weak performance, apparently some fires or fire risks. I like the idea though.

  8. Ozar | | #13

    I'm watching https://www.gradientcomfort.com/ in this space. Unfortunately for me my window isn't quite tall enough for their beta unit.

    1. kieran973 | | #22

      Me too, though if the EV world has taught me anything, it’s that when a manufacturer says some cool new green energy tech is coming imminently, that means it will actually be here in 3-5 years….

  9. _JT | | #14

    I got around to self installing a mini split the other day. It was one of the easiest DIY tasks I've done. My electrically connections were already there, the other steps took a couple hours.

    If you don't want to bother with a vacuum pump you can get a "pre-charged" unit for a few hundred more. (pre-charged is actually pre-vacuumed - they make money for selling vacuum :) )

    A 9000 or 12000 BTU heat pump sold through Pioneer is +/- $750. (COP=3.4) (Midea or GREE, hard to tell)
    A pre-charged Mr Cool is ~$1200.

    I think you will get a huge performance increase by going down the route of cheap mini split versus window unit. The window unit you linked is not AHRI listed so the COP is questionable and minimum outside temperatures are not clear.

    1. kieran973 | | #15

      Agreed. Another concern about a $600 window unit heat pump is safety. Heat pumps are most efficient when left on 24/7, but I’m not sure it’s a great idea to leave a $600 window unit with cheaper parts on 24/7 for 8-9 months straight.

      1. aunsafe2015 | | #17

        Why is leaving it on 24/7 a safety concern? Do you mean reliability?

  10. GBA Editor
    Kiley Jacques | | #18

    Here’s another model to keep in the back of your mind (it’s not on the market quite yet): Gradient. It uses R32 refrigerant (a replacement for R-410A) that has a lower global warming potential—something else to keep in mind given the EPA’s phasedown of HFCs. R-410A is the most widely used refrigerant in residential heat pumps and air conditioners in the U.S. GBA contributor Jon Harrod makes this point: “In 2036, when R-410A production is cut by 85% from current levels, there will be a large number of 12- to 15-year-old R-410A heat pumps competing for a limited supply of refrigerant. Customers who chose A2L systems early on may be very glad they did."

  11. igrigos | | #19

    You could check out the Ephoca / Innova HPAC, which is somewhere between a minisplit and a window unit in terms of cost and install. They only need (2) 6" or 8" through wall penetrations (similar to a dryer vent) and can provide heating and cooling at pretty impressive COPs. So not a plug and play like you might have been looking for, but you dont block the window and you get better heating performance

    1. aunsafe2015 | | #24

      I'd love to hear information about Ephoca from somebody who actually has one. I'd be curious to know what the temperature swing of the units is ... e.g., if my setpoint is 75, will the actually room temp vary between 74.5 and 75.5, or will it be much larger, like 73 to 77? Would also be curious to know what expectations to have in terms of long term reliability. I guess since it is completely a sealed system, with no brazed joints or flare connections, maybe we'd expect reliability to be good? (At least concerning refrigerant leaks?)

      I have some applications where I'd like to try one of these things, but for $2,000 + installation, I don't want to be a beta tester...

    2. ROBERT OPALUCH | | #25

      I think some of the Innova HPAC units do have a plug-in option according to their literature. I tried getting info to buy one in the USA but no response from the company. Seems they weren't ready to deal with direct-to-consumer or I wasn't persistent enough. These units do seem like a great option for bedrooms and are reasonably priced, less than professionally installed mini splits for bedrooms, and easy enough to install DIY (must drill two holes through the wall).

      1. kieran973 | | #26

        Hi Robert,

        Where did you learn the price on the Epocha HPAC 2.0? Have you pursued this any more?

        1. ROBERT OPALUCH | | #27

          I don't remember where I got the Epocha price estimate, probably through someone else writing about the units. Seems like a great option if you can get them. Relatively attractive and efficient. Can do a self-install if select the option to plug into an existing wall outlet (or if you are allowed to do your own electrical work). Their literature shows a range of options. Their pdf brochure is too large for an attachment. See:
          https://innova-usa.com/hpac-2-0/

          I wasn't getting responses from the company and my girlfriend decided to get a Fujitsu three 7k head multi split for the three bedrooms. She wanted a thermostat per bedroom, both AC and space heating, and didn't believe that the temperature fluctuations would be a big problem. So far its been okay but not a cheap solution. Haven't gone through mid-winter yet. Not able to set a very precise heating temp. Occasionally a bit noisy with clicking expansion sounds. Summers here on Cape Cod are mild but humid so need AC infrequently.

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