Split AC system with heat pump

[Bimmerbill]

Anyone have any experience with a split AC system with heat pump? I have a quote coming in for a Fujitsu unit for my house.

The system has AC as well as heat via heat pump and seems pretty efficient.

Preliminary quote seems a bit high, but I will get final price tomorrow.

I know heat pumps are popular down south, but not sure how effective up in the northeast.

 

[Animorph]

Fujitsu wasn't on my radar when I was shopping for one about three years ago. We don't get very cold, and that's where the heat pump's weakness is. They can have supplemental heaters though, so presumably your's will be appropriate to your area.

They work by moving heat from outdoors to indoors or indoors to outdoors, as needed. That's more efficient than just creating all the heat, like in a furnace. Though any supplemental heat will be like a furnace and may be electric. Check the efficiency numbers of your proposed units and see how they compare with other options. Get a few estimates. See if anyone has reviewed your particular units. The newer heat pumps have much better efficiency than a few years ago, so hopefully your heating/cooling bills will go down noticeably.

 

[GrayHare]

Since they extract and concentrate heat from the air, heat pumps are efficient. Many units are surprisingly noisy, particularly when defrosting themselves in cold weather. Of the six heat pumps I've had experience with at various locations, two have had chronic and tough-to-repair problems when switching in the spring or fall between cooling and heating modes (they get "stuck" in mode of the prior season). In heat mode, heat pumps generally dispense warm not hot air, which can give some a feeling of draftiness.

 

[pb4uski]

I looked into it when we rebuilt last year.

The conventional wisdom was that they worked well providing heat down to a certain temperature (about 0F IIRC) and then did not work well below 0F. However, there were some "new" technologies that claimed to still heat efficiently down to -20F or colder. At colder temperatures, an electric coil-type heater kicked in.

I made some inquiries and the vendor never got back to me and our construction schedule required that I make a quick decision so I went with a more conventional system.

If the electric rates in your area are affordable (ours are not) then it might be a possibility for you, particularly if you are in the southern part of the state.

 

[Bimmerbill]

The installer said they work pretty well to about 10F. I just put in a pellet stove this year, so have plenty of heat available in addition to my oil furnace. Oil was up to 3.90 a gallon tho, and expensive.

I kept my oil heat set at 60 all day, then when I get home I fire up the pellet stove.

 

[samclem]

If you've got another source of heat when things get really cold (oil or your pellet stove), if cheaper sources of heat (natural gas) are not available, and if your electricity rates are reasonable, then a heat pump can be a good choice for mildly cool days.
We had one in North Carolina, and when it got too cold for the heat pump the "heat strips" would come on. That happened at about 30 deg outside temperature (units might be better today). Those "heat strips" are pure electric resistance heat--$$$ouch$$$.

Fujitsu--not known as a low-cost system provider if I recall correctly. Be sure to get other quotes.

 

[Animorph]

I've got three heat pumps. Two are original from late 1991. One we replaced in the first year of the energy saving rebates (2009?). The repair guy actually fixed the replaced pump with just a capacitor, so nothing really wrong with it. No maintanence, no problems other than that one. But hardly ever below 30F here, and they run more in the summer. Ours are Trane.

 

[JakeBrake]

We have a mini-split heat pump with supplemental reasistance heating we use to cool a 600 sq. ft. second floor bonus room.

The unit was installed in the year 2000. The unit has a Carrier nameplate, but was not made by Carrier. I'm told that all mini-split heat pumps are imported to the USA. DW did place a fake fireplace heater in the room this winter. I think it's more for the ambiance than the heat.

So far, the unit has worked very well. We have hot, humid summers and mild winters here.

 

[Bimmerbill]

I will have to look up the specs to see if it has resistance heaters installed. I don't want that, but will take the heat from the heat pumps, especially if its very efficient. Guy said SEER19, but I will look up specs now that I have the model numbers.

 

[bld999]

I will have to look up the specs to see if it has resistance heaters installed. I don't want that, but will take the heat from the heat pumps, especially if its very efficient. Guy said SEER19, but I will look up specs now that I have the model numbers.

The site: "Heating Help" has a section on a/c and refrigeration. The site is designed as a group of experts and practicioners who answer consumer questions in addition to helping other pros troubleshoot stuff. If you post up your questions there, they will steer you right in a hurry, but expect to leave with homework and return with answers. They are a rigorous bunch, and aren't typically satisfied giving general answers.

I'd post a link, but don't know if allowed.

 

[liveaboard_frank]

SEER 19's not that good... I just bought a Lennox unit that's SEER 22 and am quite happy with it, but that's not even that great. There's some foreign-made brands that are more efficient (in the high 20s), but Lennox is pretty much all USA-made. This page was pretty useful in making my decision. Sorry to bump the old post, I just thought it was worth mentioning that there are a lot more efficient units around now.

 

[DAYDREAMER]

I purchased an LG 18000BTU ductless heat pump on line and self installed. Cost about $2200 total after buying vacuum pump and some other equipment. Heats the house great with outside temps 25F-50F, but really works hard below 18. Air condition is amazingly powerful. Used 1/3 the energy of baseboard heating, and the heat output is very consistant. The unit has a dc inverter motor that is variable rate, and adjust pump speeds to match needed heat.

I live in the washington state which has mild climate. Heat pump is perfect for the environment conditions.

 

[meierlde]

One thought if you currently have access to gas is to use the heat pump and the gas furnace as backup. (basically the gas furnace takes the place of the resistance strips) In my experience with 3-5 year old units, at around 20 the resistance heat kicks in. At that point the outside units run continuously, and the strips kick on and off. I download the detailed manual and found the following ratios of heat gained to electric power in vs temp At 65 5.66 the electricity is gained as heat at 60 5.45, 55 5.20,50 5.02,45 4.71, 40 4.25,35 3.74, 30 3.62, 25 3.48, 20 3.33, 15 3.15. Of course as the temp gets lower the heat output needed to maintain a temp goes up. So when the heat output needed to maintain a temp exceeds that from the heat pump is when the resistance strips kick on.