3 mini split heat pumps, first day.

M. Moore said:

Just wondering why you would run at 30% humidity? Normal comfortable range for humans is 50-70%. If you are thirsty all the time it is probably because the air is too dry.
Very lucky here where I live as the indoor humidity level is in that range all year.

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HVAC techs say 30-50% but anyway, it is probably because we live in a arid state our whole lives and we are used to the drier air. it is fairly strange as we monitor this system. The temp cant get below 75° with all the machines running, which seems high, but as long as the humidity is low it is all good, if the humidity even goes up to 40% your sweating bullets, and we are just 2 little skinny guys.

@Scruffy887 Are you using these mini splits for heat now? How are they doing? How do the 24K units do for "throw power"- How far do the fans push the air?

I was going to do the same thing, but then have been told by two HVAC techs, one family and one friend, two avoid the cheap china mini splits at all cost as they just don't deliver what the label says they do, especially heating below 40 degrees. So that narrows it down to Mitsubishi or Daikin. Then I'm told two 36K units would be much better than three 24K units for my space, as the 36k single zone units have a much larger fan and "throw" the air further in your space.

The bitch is that 36K single zone is not all that common. They're hard to find and will cost me about $2000 more for a pair of 36k's than three 24K's would cost.

Or I could save $4000 and buy a few Senvilles or Cooper Hunters or Pioneers, but I think I'm going to go for the Jap brands after listening to first hand accounts of issues with the China units.

Garwood said:

I was going to do the same thing, but then have been told by two HVAC techs, one family and one friend, two avoid the cheap china mini splits at all cost as they just don't deliver what the label says they do, especially heating below 40 degrees. So that narrows it down to Mitsubishi or Daikin.

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My brother installed a $700 1 ton daizuki heat pump in Bellingham WA, (they were 650$ a year ago when I put one in) it has no problem keeping his 1200 square foot manufactured home warm in 9 degree weather. It has 2 capillary tubes and a check valve so it is more efficient than the single capillary tube 650$ one ton units made by other manufacturers. (The check valve bypasses half the capillary tube in heat pump mode)

Also it intelligently senses the coil icing up, if it's not iced up it doesn't defrost it. Anyhow his unit has an issue with overshooting the temp set point.

I have heard bad things about stepper motor driven refrigerant metering devices.... They leak. Factory brazing on the stainless to brass transition is not reliable. And at the going rate for HVAC technicians, if they get called more than once every 10 years to repair your crap outside of warranty, your high efficiency unit just lost it's entire advantage.

Garwood said:

...

I was going to do the same thing, but then have been told by two HVAC techs, one family and one friend, two avoid the cheap china mini splits at all cost as they just don't deliver what the label says they do, especially heating below 40 degrees. So that narrows it down to Mitsubishi or Daikin. ...

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A big thumbs-up for Daikin here. I have a 1200 sq ft shop in Maryland, reasonably well insulated but with a 12' overhead door. Two years ago I installed a 2 ton Daikin minisplit purchased for $1,550 shipped, off Amazon no less (they had the best price which has since gone up a bit):


I installed it myself with a dedicated KWh meter so I could tell how badly I was impacting my electric bill. To heat and cool for a full 12 months it uses about 1,340 Kwh of electricity (or $140 at the local electric utility rate -- ~$12 a month!). Much better performance than I'd hoped for, and in hindsight I think a 1.5 ton unit would have worked (I tried slogging through a "Manual J" calculation which was closer to 2 tons but involves guesswork).

Best of all this heat pump has a "dehumidify" mode where it runs with a very cold evaporator and very slow blower speed to maximize moisture removal (versus overall cooling). In our humid summers I see condensate coming out of the drain tube in a steady stream.

My unit was precharged, but I did need to evacuate the lineset which I also had to braze in several spots. I already had the HVAC tools but even if I bought a pump and micron gauge the total cost would have been less than paying for professional installation. I'm also not worried about the fact that as a DIYer there is effectively no warranty; the technical documentation is excellent and worse case the head and base units can be purchased separately. I could buy one of those for a drop in replacement for less than a typical HVAC service call.

-Steve M.

Garwood said:

@Scruffy887 Are you using these mini splits for heat now? How are they doing? How do the 24K units do for "throw power"- How far do the fans push the air?

I was going to do the same thing, but then have been told by two HVAC techs, one family and one friend, two avoid the cheap china mini splits at all cost as they just don't deliver what the label says they do, especially heating below 40 degrees. So that narrows it down to Mitsubishi or Daikin. Then I'm told two 36K units would be much better than three 24K units for my space, as the 36k single zone units have a much larger fan and "throw" the air further in your space.

The bitch is that 36K single zone is not all that common. They're hard to find and will cost me about $2000 more for a pair of 36k's than three 24K's would cost.

Or I could save $4000 and buy a few Senvilles or Cooper Hunters or Pioneers, but I think I'm going to go for the Jap brands after listening to first hand accounts of issues with the China units.

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I only have 2 units heating at present, 65 degrees inside easily. No issues with throw and the inside units are about 8 feet from the floor. I do not use the SWEEP function, just aimed where I want the air to go. As said before they are located to move shop air clockwise. No issues at all. Current space is about 40 x 60 and one short end is only a blue tarp. Other side of tarp is not heated.
This week I will seal the holes where the lines went through the walls. Never did that but winter is here. Also need to make a snow deflector for the unit on the eve end of the building. Don't want a snow avalanche to tear the outside unit off the building.

When I factored cost, availability and warranty I ended up at the Midea units sold as Pioneer or Senville brands. I could not find a reason to spend $200 more for Pioneer, in fact I found a few more glowing reviews of Senville, so I bought a pair of 36K 17.5 SEER Senville heat pumps for $4500 delivered. Should be here just after Christmas.

The same units from Daikin would have been $7800. Mitsubishi $8500. But with those brands I would have no warranty whatsoever unless I paid full retail plus Install. Then if there was a warranty issue I'd have to pay a pros labor to handle it. What a joke.

For $2200 each delivered I can just buy another heat pump, but the cheap ones have a 5 year warranty.

11 degrees when I got to the shop this morning and last night was windy too. Shop was a toasty 65 degrees and one of the HP units was cycled off. When I left last evening I set the oil unit to 60 as a backup to the HPs. It was not needed. And only 2 of the 3 units are on line. Pretty happy so far. Laser thermometer shows 90 degree air output if aimed inside the grill.
These are Pioneer Dimante low ambient units.

Garwood said:

For $2200 each delivered I can just buy another heat pump, but the cheap ones have a 5 year warranty.

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With what real 'installers' want, It is a serious consideration to buy a spare. The one in my shop is dying and I will replace it thus year I guess. First one I have had to do so. 3 at the house are all 14 years old, this one is not that old but was cheap off brand. AC only, although they all heat.

gustafson said:

With what real 'installers' want, It is a serious consideration to buy a spare. The one in my shop is dying and I will replace it thus year I guess. First one I have had to do so. 3 at the house are all 14 years old, this one is not that old but was cheap off brand. AC only, although they all heat.

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I don't think I have room to store a spare! These things are huge!

They came Fedex freight and I thought I got everything on one huge pallet. I got it inside, opened it up and it was just the two outside units on one pallet. I called Senville right away, excellent customer service. They said if they couldn't find the rest of the parts they would ship out replacement units that day. They worked with Fedex to track down the rest of the pieces, Called me a few hours later to say they found the rest and all was good. Next day Fedex dropped off the pallet for the indoor units and parts kits.

Haven't got them installed yet. Insulation and interior paneling are happening first. Plan to fire the first one up in a few weeks though.

Hey Garwood, stay warm! I am. My oil unit has not run since I did the season start some weeks ago. Still set at 60 but not needed. These Heat Pump units keep my space very comfortable and are so quiet I seldom notice them running, even when the machines are silent. Also hard to hear them outside.
Take your time and be methodical with the install. There is a huge line pressure difference between cooling and heating. Get a sniffer and don't forget bubble leak stuff too. Do not use soap.