Opinions on heat pump backup

[brant2000]

Mini's have two heads and one unit outside. At least that's what iv been told

I believe those are mitsubishi's "city multi" units. There may be others that use a similar arrangement, but these were the original.

 

[That's Right]

Well I went with what I had as far as backup..electric coil. Now I've got a new 4ton 15 seer hp. I can't believe the difference in air temperature. The air is actually hot compared to the old unit.
Thanks for all of the help.
By the way it is snowing blowing like crazy here. Had the perfect storm/situation happen. B-day party for my 1yoa baby girl. Electricity goes out. P61 in the basement started to leak alittle smoke. Fired up generator and newly wired box. Everything worked like a champ. That's a non pure sine wave generator by the way.

Again thanks for the help/replies. This Site is awesome

 

[brant2000]

Glad everything worked out and that your happy with the new HP. Happy birthday to your daughter!

 

[maple1]

Mini's have two heads and one unit outside. At least that's what iv been told

I'm quite sure that one head in & one unit out is also a mini-split.

 

[heaterman]

Mini's have two heads and one unit outside. At least that's what iv been told

You can get inverter style mini's with anywhere from a single to 3 or maybe 4 indoor units.

 

[_CY_]

difference between a ductless mini-split is lack of ducting ... each room/area has it's own refrigeration lines which goes to a self contained register with blower. outside main condenser are all different sizes to support larger number of circuits. each room/area has it's own circuit.

410A outside DC compressor is inverter driven at variable speeds depending on loads. inside registers are AC driven .. 27 seer is not uncommon. sensor driven compressor fan and other features bumps efficiency. one drawback is not that many refrigeration techs are up on service/installation for ductless mini-splits. they really are different ..


vs 13 seer for lowest rated HP .. up to 24 seer for max efficient conventional compressors with variable inside fan with solenoid operated liquid line controls, etc.

it needs to be pointed out again ... when burning a high efficient wood stove like Buck 91 Cat 24x7 ... your HP/natural gas heater only should run a few times a day. doesn't what type backup heating system you've got. it's only when relying on HP or what ever as primary heat source .. operating costs becomes a factor.

 

[DBoon]

Maybe it's just my unit, but I'm very skeptical about the HSPF vs. "real world" efficiencies.

Yes, it is just your unit, and I was very skeptical as well before I read all of the glowing reviews about the mini-split performance in cold weather. But they deliver. When it was 0 degrees F outside this winter, the air coming out of my mini-split indoor cassette was very warm.

Having grown-up in the "bogus" era of conventional ducted heat pumps, I was very skeptical of mini-split claims. To me, heat pumps were inefficient ways to blow ~75 degree heat around the house and watch the electric resistance heat run half the time (it seemed) anyways,. I could also never get the wife trained to not turn the temperature up quickly when she was cold, so the electric resistance heat was running half the time anyways. Mini-splits just pump out heat even when it is very cold, and never turn on electric resistance heat.

Conventional ~12 SEER heat pumps are no comparison to a good mini-split.

 

[potentialburner]

Having grown-up in the "bogus" era of conventional ducted heat pumps, I was very skeptical of mini-split claims. To me, heat pumps were inefficient ways to blow ~75 degree heat around the house

Even the older "colder" heat pumps didn't blow air that cool. It was low 90s but felt cool because it was below body temperature. Of course that fact didn't make them comfortable.

I have one that's getting older (1999 install) and the air it blows is comfortably warm. It was top of the line then, probably at the lower end of performance by today's standards.

Conventional ~12 SEER heat pumps are no comparison to a good mini-split.

I thought SEER was a measure of cooling, not heating, efficiency.

 

[potentialburner]

BTW how much noise do mini splits make? Would I be annoyed having one right over my bed?

 

[flyingcow]

BTW how much noise do mini splits make? Would I be annoyed having one right over my bed?

I don't think they noisy at all. The fan is very quiet. If they've been shut off, a bit noisy upon start up trying to cool or heat room to temp. But thats just until it gets close to temp, it will ramp down the closer it gets to temp.

 

[peakbagger]

My Mitsu mini split has three speeds. It is quite quiet on low but is noticeable when on medium. On high its noisy. Mine is mounted very close to where I sit to watch TV so it location is also an issue but I needed to put it there to get the outside unit in the best spot (Out of the prevailing winds and on a sunny wall) In normal operation running it on low is fine. If the unit has been set back and I need to heat the area up, medium is needed for an hour or two. I heat the second floor of my house with the unit on the first floor when possible and in cold condition, I need to run the fan on high. One thing to be aware of is the amount of heat the unit puts out drops as its gets colder while the amount of heat you need goes up. The unit still puts out heat at subzero temps but the btu/hr and the temp also drops. I found this winter that in cold temps, the unit really doesn't deal well with setting back the temp, just set it at one setting and leave it.

In cold damp or snowy conditions, they are somewhat noticeable when going through a defrost cycle. Its not that it loud as much as it sounds like someone is messing with the controls as it cycled through the defrost cycle. If its clear out, it doesnt happen often but in cold snowy conditions it may cycle every hour.

 

[brant2000]

Yes, it is just your unit, and I was very skeptical as well before I read all of the glowing reviews about the mini-split performance in cold weather. But they deliver.

I also have heard great things about minisplits. My comment was in regard to large, ducted split systems like mine. Just like you mention in your post, mine blows slightly warmed air and runs constantly when it's cold out. Aside from the expensive electric bill, the constant noise of my blower running 24x7 drove me nuts.

 

[flyingcow]

In cold damp or snowy conditions, they are somewhat noticeable when going through a defrost cycle. Its not that it loud as much as it sounds like someone is messing with the controls as it cycled through the defrost cycle. If its clear out, it doesnt happen often but in cold snowy conditions it may cycle every hour.

Thanks for reminding me peakbagger. I should have mentioned this also.

 

[heaterman]

My Mitsu mini split has three speeds. It is quite quiet on low but is noticeable when on medium. On high its noisy. Mine is mounted very close to where I sit to watch TV so it location is also an issue but I needed to put it there to get the outside unit in the best spot (Out of the prevailing winds and on a sunny wall) In normal operation running it on low is fine. If the unit has been set back and I need to heat the area up, medium is needed for an hour or two. I heat the second floor of my house with the unit on the first floor when possible and in cold condition, I need to run the fan on high. One thing to be aware of is the amount of heat the unit puts out drops as its gets colder while the amount of heat you need goes up. The unit still puts out heat at subzero temps but the btu/hr and the temp also drops. I found this winter that in cold temps, the unit really doesn't deal well with setting back the temp, just set it at one setting and leave it.

In cold damp or snowy conditions, they are somewhat noticeable when going through a defrost cycle. Its not that it loud as much as it sounds like someone is messing with the controls as it cycled through the defrost cycle. If its clear out, it doesnt happen often but in cold snowy conditions it may cycle every hour.

How old is your Mits and is it an inverter type unit?

 

[peakbagger]

My mitsu is a hyper heat inverter unit bought last year. I have strictly AC Mitsu seven years old in my office. The blower noise is just about the same. Barely noticeable at low, and noisy on high. I am considering replacing the office unit with new heat pump (another NH rebate).