heat pumps...

[cfz2882]

Mr slim working good

released the charge into the system and working good so far-quite impressed with the performance and unit is very quiet: inside just a quiet rush of air,outside,running full speed,compressor noise about the same as a typical refrigerator while the 3-blade condenser fan sounds similar to an old 3-blade 20"box fan.With a ~50*outside temp,heat output feels similar to about a 3000w electric heater.might have to wait for next summer for a proper test of the cooling function .In cool mode, the air discharge slats position to blow air outward,while in heat mode air is directed at the floor.

 

[cfz2882]

very quiet,but...

the MrSlim is great-got to test out the cooling on a semi- hot (87*)and it handled this with ease-quickly kicked down to low speed then cycled off.I thought there might be some "fluid noises"gurgling,hissing,etc. from the indoor coil,but there is none. When unit runs at low speed,a low frequency throb can felt on the outdoor unit cabinet-kinda similar to a 1985 chevy citation 4 cyl. engine idling .

 

[cfz2882]

heat mode test

had a frosty 30*morning the other day,started the MrSlim and it was soon putting out a stream of 112-130* air-almost hot The conduit through which I routed the refrigerant lines outdoors became slightly warm in the 30*temps,so will go back and increase the insulation of those lines-wrapped each line with ~3/8"thick foam insulated pipe wrap-will increase insulation to ~3/4"thick and route through bigger conduit.

 

[ilovewindex]

Daikn Ductless HeatpumpOr

I commented on the other HVAC thread, but I love my Daikn... It does so well and my house is very open and air flows through...

Cooling upstairs is a tad harder because of the ceiling height and an uninsulated sky light, but it does ok...

Mine is 24K and my house 1400 sq ft under air... If i put a second 7k to 10K btu unit upstairs it would help fix the few short comings.

For the price I paid after rebates, the $2200 is well spent and my house is comfie... I couldnt go back to the forced air furnace.. I am afraid of gas, hate the smell of oil and steam is just too much here

 

[cuffs054]

Funny, I feel the exact opposite. I've had heat pumps in all my houses since the early 70's and never was keen on them. The new old mini manse has a Gas Pack with floor vents. Boy, does the real "heat" feel great!

 

[cfz2882]

daikin

some consider Daikin to be the best minisplit brand-better than Mitsubishi or fujitsu,those two brands also generally spoken well of.So far,mine is the only residential minisplit I have seen locally,but I have seen some installed on dentist offices,hospitals and visitor centers:most are Mitsubishi,but fujitsu,daikin,and sanyo have been seen local.Part of the reason the Japanese minisplits are very effective in heat mode might be the electronic-modulated expansion valve and variable speed compressor.

 

[washer111]

Inverters and all the whizz-bangery are great now when they work - but what about in a few years time? 

 

Electronics are not built well anymore. So what will happen with "dirty" power supplies, surges, brown-outs, lightning plus moisture? 

 

A simple central A/C unit, installed properly will remain far more fixable for much longer. It may also work better too. It won't become junk just because a control board for the inverter costs nearly as much as a new system. 

 

That's why I resist these things. You spend a small fortune installing them - and a failure in a couple of years could ruin in "savings" you got replacing a reliable, old system. 

 

[cfz2882]

that is a worry...

...the possibility of a lightning strike causing expensive damage to modern electronics-laden HVAC equipment:i thought about adding a line reactor to the Mr Slim power feed,but looked like there was one built in already-along with some gas type surge suppresors.will turn the breaker off when a lightning storm approaches though (same thing with my electronics laden 2010 bosch dishwasher)

 

[kb0nes]

Overall the state of the electronic art is better and far more reliable then it ever was in the past. The oft heard Mantra that older is better is often just not true.

There is no doubt that manufactures cut costs and use inferior components and omit filtering and protective devices. Provided a bit of care in the design I'd much rather have newer then older. Older mechanical only systems weren't trouble free either and the added benefits of the sophistication greatly outweigh the added complexity (see also fuel injection).

It isn't a bad idea for any home today to have a transient voltage suppressor installed at the main service panel of the home. One of these will provide bulk protection of the entire home to the degree that most connected devices will do just fine. I still have point of use protection at sensitive devices and I won't run any computer (that I care about) without a UPS. Full disclosure, I maintain a bunch of radio equipment on some local water tanks with the antennas high in the air. I may be a bit more paranoid about transients then others due to this!

 

[washer111]

Thanks Phil

I suppose it may also boil down to purchasing products from larger, reputable companies. However, I think with some technologies, even if products are better, keeping things as simple as possible ("KISS," anyone?) reduces the possible points of failure (see my post about inverters above).

 

 

So if we had two A/C units from 2015, I'd say the non-inverting unit from a reputable company would last longer than an inverter unit from the same, or maybe different reputable company - just out of the fact that there is (far) less to go wrong and less electrical equipment that could be damaged by environmental conditions or freak power accidents. 

(Although I certainly do take the point of household shielding system. Thats worth some research, I think). 

 

Several houses around here use the multi-head Fujistu units, and all I know is they are bunches of temperamental rubbish. One friend had one 3-head unit that was replaced, and still malfunctioned during his 3.5yr stay. A head from the unit for the "other side of the house" experienced a clogged drain or perhaps poor leveling and flooded the loungeroom. 

 

Personally, if I/We were to take the mini-split route, I would investigate using chilled water (we don't need heating in these parts). The actual refrigeration is all self-contained, then just some water and electrical pipes from there. No need of needless complication. 

 

[kb0nes]

Somehow I think the idea of using water (or something) as a heat transfer fluid because you are concerned with complexity/reliability is crazy! You are adding an extra layer that will only negatively effect efficiency and reliability.

The problem isn't lengthy Freon lines, if the installer does the job correctly lengthy refrigerant lines will never be a problem. If the installer is a hack you will have potential problems with anything he/she touches.

 

[cfz2882]

measured current draw

25*this morning and MrSlim putting out ~130*air,pulling 5.2 amps(230v)with compressor sounding like running ~4000 RPM- maximum current rated at 7.2 amp.Kinda weird hearing compressor running faster than ~3400 of line driven induction motor compressor.Running easy,~2000 rpm,amps was 2.5 A. Did see it run a defrost once-stopped the fan motors and ran the compressor to about 2000 RPM a stream of water running out the drain of the outdoor unit.

 

[tolivac]

The "Slim" units we have at the transmitter plant are completely quiet outside-no sounds at all.You see the fan turning at various speeds.The room unit is silent,too-have to check the vent on it to see if its going.And most of these units have been running year round here for many years.Mitshibishi and Fredrick brands.One thing interesting between the brands-the fans on the compressor units turn in opposite directions!Of coruse the weather here is much more mild than the SD winters!If those units warm during the SD winters-its a really good unit!I used to live in Rapid City SD-the winters here are nothing!The main diffence here is you get more freezing rains.Raises hob with the antennas!

 

[cfz2882]

winter performance good

was down to ~5*the other night and the MrSlim was still putting out decent heat-have been running it a lot lately-increased my electric bill by about 30%,but my usage is pretty low anyway and gas bill seens unusually low now... snowing here all day,runs a defrost every couple hours-gives a puff of steam when the outdoor fan kicks back on after a defrost.