Mini-Split heat pump for room in pole building?

[Texas Ranger]

Addendum:  Put a serge suppressor in the line .  I found out the hard way.

[gspren]

Addendum:  Put a serge suppressor in the line .  I found out the hard way.

While surge suppressors can save a problem they can only handle so much, when the neighborhood had a major surge a few years ago those that had whole house protection got to add the cost of burnt out surge protectors to everything else, still blew out the modern appliances, tvs etc. only the old pre computer refrigerators that some of us had in our garages survived.

[Tacotodd]

The "surge" suppressors that I was thinking of were for a different kind of surge ;) NOW you know where I'm at, at least in my mind ;D

[Larry]

I got a bid on a Samsung 18k btu Single Zone Mini Split for the shop last week.  $3,800 seems high to me.

Right now I AC with a 18,500 btu window unit in 1,500 square foot well insulated tight shop.  Heat is 24/7 from a Vermont Castings wood stove.  First window unit lasted 7 years and I'm about that far along on the one I'm using now.  They work well and not much cost.

Still I would like to explore a mini split.  Have to contact a few more HVAC guys.  I'm also not afraid of a DIY unit. 

[peakbagger]

I installed my own Mitsubishi cold climate mini split but paid a tech to pump out the lines and charge the unit. It took them about 2 hours and charged me $250. It they had installed it complete it would have been about $2000. The Mr Cool units they sell at Costco reportedly come with precharged lines so its just plug and play (but the efficiency is lower than the name brands).

[SwampDonkey]

Still I would like to explore a mini split.  

Up here you won't get one for less than $6500 installed. That puts the brakes on the deal pronto. :D

[Crusarius]

3 zone unit for my house installed to replace the failed one is 15k. that is a 3.5 ton Gree unit. After this year, its worth every penny!

Of course install is scheduled for october sometime. 

[Downstream]

I just started researching these for my 24x24 detached workshop.  The MrCool units seem pretty easy to install and do not need ac tech to charge lines.  Has anybody installed these or another brand that was pre-charged?  Also the 12k btu ones say up to 500 sqft for heating and cooling so once again has anyone used that size for their 24x24x8 ceiling building?  I will be insulating the walls, ceiling, and garage door.

[Crusarius]

Be careful with the self install ones if you care about a warranty. There is fine print saying no warranty if you install it yourself on some of the units.

[petefrom bearswamp]

Mini split in the house, kind of a brand x I went with cause the company is in the US.
The system is of course imported from china.
Self installed, professionally charged.
Use it for AC only.
Have had 2 issues with it, the first mice got on the main board and built a nest causing it to fail.
$300 bucks later it ran OK for 2 seasons.
I took all the sheet metal off and mouse proofed it.
It now has been down about a month, the other board fried.
Part on order until late Aug, early Sept.
Probably wont have it operational until AC season nearly over.
Warrantee long gone with no issues.
My well insulated shop 32x56x 10' ceiling 4" concrete floor with no AC would stay cool but very high humidity.
Put a room dehum in and it now stays from 68 to 72 degrees with humidity around 40.
The unit runs continuously and I have no idea how long it will last.
cost about 275 bucks and I can buy a bunch of these as needed before it reaches the cost of a mini split system.
At my age the mini split is not cost effective.
I had thought about another self installed Mitsubishi system from AC direct costing about $3500 or so, but the dehum is working just fine with no great rise in elec cost.
My heat comes from a 55 gallon drum stove.

[Larry]

The MrCool units seem pretty easy to install and do not need ac tech to charge lines.  Has anybody installed these or another brand that was pre-charged?

Along about 1980 I walked into the local Sears Roebuck store.  Remember them?  I gave them the size of my house, window location, and insulation.  They figured out the size central air conditioner I would need.  Gave them some money and walked out with a central air conditioner, A-coil for my furnace, thermostat, and pre-charged lines.  A week later I was cool doing all the work myself with no experience.  Sears sent out a HVAC guy about a month later to check out my work.  Think he added a little Freon and that was it.

So, the DIY technology is not new, and I suspect its improved.  I would think a mini-split might take half a day to install.

 

[hedgerow]

Along about 1980 I walked into the local Sears Roebuck store.  Remember them?  I gave them the size of my house, window location, and insulation.  They figured out the size central air conditioner I would need.  Gave them some money and walked out with a central air conditioner, A-coil for my furnace, thermostat, and pre-charged lines.  A week later I was cool doing all the work myself with no experience.  Sears sent out a HVAC guy about a month later to check out my work.  Think he added a little Freon and that was it.

So, the DIY technology is not new, and I suspect its improved.  I would think a mini-split might take half a day to install.

Over the years I have repaired a ton of these type of units. Those screw together connections start leaking on the high side and leak the charge out. We just cut the screw type connections out and solder in new connections add a filter, pump the system down and charge back up and your back cooling again. A lot of mobile and modular homes around hear had this type of units installed in them.  

[petefrom bearswamp]

Larry, took my friend and I a half day as you stated above
That was just putting the units in place and connecting the lines.Had an electrician friend hook up the electric end, took him an hr and a half.

[scsmith42]

To my knowledge all of the mini-split units come pre charged with Freon. With respect to DIY installation, The issue is not so much charging them as it is the need to remove all of the air and purge any moisture out of the line set.

Charging them is a simple matter of opening both valves on the compressor / condenser unit to let the Freon into the rest of the system.

All things being equal, a system that has been properly evacuated (draw a vacuum) after installation will cool better than one that was not.

[Tacotodd]

29.5" of mercury for a minimum of 30min is supposed to be the shiznit, at least that's what "I" was taught in our automotive ac classes that I was "allowed" to attend :D

[metalspinner]

Mine is up and running! This was installed by my HVAC guy and inspected by the city. 

A mechanical inspector and the electrical inspector came out to look. This was installed on a 20 double pole breaker. But the electrical inspector made him change it to a 15 amp double pole. 

 I wanted the outside unit up high so it would be out of the way. It is amazingly quiet. 

This room is about 400 sq/ft.