DIY mini split as a temporary (a few years) install?

[Mithril]

Ok, so I've never installed a mini split before, closest experience is fixing the AC in a car (new condenser, vacuum down the system etc).

These ~$500-700 mini split heatpump systems don't look all that hard to do, if the lines are not pre charged you need to have/rent a vacuum pump and may need to add refrigerant. Seems straightforward.

How are these units if you need to de-install and re-install them (take them with you moving, handle a remodel, whatever)? I'm aware I might need to reflare and/or replace fittings on the lines.

How crazy would it be to run the lines through a small window and build a small box to mount the interior unit on? Of course building something out of wood or such to safely transition and seal the open window (I've done this for floor units with hoses as the included plastic stuff is usually garbage).

Or would I be better of spending the money on a window or floor unit heat pump. If so, which ones are worth getting? I'd actually prefer it didn't have resistive heat (or that it can be disabled).

I'm also looking for a 120V unit (regardless of type), I'm aware that limits the size.

Reasoning:

• We are not planning on staying here long term. I don't want to take the time to make the install "house selling friendly" beyond safety (GFI, properly rated wiring), and I'm not planning on converting the whole house.
• This specific room/area is somehow prone to extreme heat in summer and extreme cold in winter more than most of the rest of the house.
• Cooling needs of the rest of house are handled by existing window and floor units.
• Heating is central nat-gas, which grows more and more expensive, and supplemented with space heaters which (you guessed it) are getting more expensive to run
• replacing the heating system is not in the cards.
• The room in question is the worst offender for "excessive space heater use".
• AN absolute "base model" window AC is going to run say 200-300 anyways.
• my "back of the napkin" math puts savings at ~150 per year by replacing said space heater use

So to sum up my 3 key questions:
How easy/possible is it to move/reinstall minisplits
How insane is it to NOT drill holes in the wall and use a window (sealed sanely) as the passthrough?
If the above two are "just don't", whats a good window/floor heatpump?

 

[Mithril]

Any thoughts/suggestions?

 

[Supervstech]

I jave several minis in my storage unit i setup for customers needing temp heat and cool...

That said, a dual pipe portable unit is far simpler and more reliably setup.

 

[Quattrohead]

https://www.amazon.com/Midea-Inverter-Conditioner-Flexibility-Installation/dp/B08677DCKN/

 

[Rednecktek]

The dual pipe heat pump units are going to be your best bet. You can totally move and reinstall mini-splits but pre-charged or not you still have to vacuum them down.

The standing units usually have all the window blocking parts you need anyways so that saves work on both ends. They're about the same performance as the cheaper mini-splits to boot.

As for units, look at the Midea units. I know a couple people with those and they all swear by them.

 

[Supervstech]

Anotjer option with low buck mini units are the sharkbite style refrigeration fittings.
Much easier than flaring and reusable.

 

[Mithril]

The dual pipe heat pump units are going to be your best bet. You can totally move and reinstall mini-splits but pre-charged or not you still have to vacuum them down.

The standing units usually have all the window blocking parts you need anyways so that saves work on both ends. They're about the same performance as the cheaper mini-splits to boot.

As for units, look at the Midea units. I know a couple people with those and they all swear by them.

Sure, I figured I'd have to vacuum it down to deinstall.

In my personal experience of the "just AC" style the floor standing units are not as effecient and cost more

Any specific ones? when looking in the past it's been hard to tell if the unit was truly heatpump or JUST AC and if it had backup heat or not

 

[Mithril]

https://www.amazon.com/Midea-Inverter-Conditioner-Flexibility-Installation/dp/B08677DCKN/

Wish they made more units for side sliding windows so I could not make to make adaptors lol.

How is this in cold, how far down will it really heat? Oh, looks like it might be AC only

 

[Rednecktek]

The Midea portable heat pump is what I've seen at my friends' place. They all love it.

 

[Mithril]

Thanks for the feedback, seems like a "you could, but maybe you shouldn't"

SO maybe plan B is saner. Hows the SEER/efficiency in comparison should I redo my "how worth it is it?" calculations

 

[Rednecktek]

The SEER rating is pretty low in comparison, so really it's more about how much work you want to put into it. As a reefer tech I find the flaring and vacuuming process isn't difficult but the up front cost for the equipment, even at Harbor Freight, is substantial if you're only using it once or twice. It does take practice and there's a short learning curve but once it all clicks it's a skill for life.

So your choices come down to 12 SEER and 5% work or 22 SEER and higher up front costs and work. Is the energy savings going to be greater than the equipment cost over the time span even counting your labor for free.

 

[Mithril]

The Midea portable heat pump is what I've seen at my friends' place. They all love it.

Hmmmm, only heats down to 41F? Unfortunate and with the price maybe not the right buy for me, I fear it would not be able to run enough in winter.

 

[Mithril]

The SEER rating is pretty low in comparison, so really it's more about how much work you want to put into it. As a reefer tech I find the flaring and vacuuming process isn't difficult but the up front cost for the equipment, even at Harbor Freight, is substantial if you're only using it once or twice. It does take practice and there's a short learning curve but once it all clicks it's a skill for life.

So your choices come down to 12 SEER and 5% work or 22 SEER and higher up front costs and work. Is the energy savings going to be greater than the equipment cost over the time span even counting your labor for free.

Well, I don't think I'd need a flaring kit for initial install (I don't mind leaving the pipes long and coiling them) or de-install. Likely only for re-install (at which point I might be getting more mini splits for the new place anyways). Vacuum I could rent if needed for install, and decide later if I want to just buy one (feels like a good investment if you have 2 or more you can do your own maintenance)

Well, back to over thinking I guess lol

 

[Mithril]

I jave several minis in my storage unit i setup for customers needing temp heat and cool...

That said, a dual pipe portable unit is far simpler and more reliably setup.

For these setups did you do a "normal" install (holes through the wall)?

 

[Rednecktek]

If you can find a place locally that will rent the vacuum pump, guage set, and fittings then go for it. Around here the few places that have that stuff available want to see your EPA608-U or 609 card before they'll rent. If you feel up to it a 12k BTU 120v mini split can be a good investment.

 

[Rednecktek]

For these setups did you do a "normal" install (holes through the wall)?

Included window adapter.

 

[whitedog]

Ok, so I've never installed a mini split before, closest experience is fixing the AC in a car (new condenser, vacuum down the system etc).

These ~$500-700 mini split heatpump systems don't look all that hard to do, if the lines are not pre charged you need to have/rent a vacuum pump and may need to add refrigerant. Seems straightforward.

How are these units if you need to de-install and re-install them (take them with you moving, handle a remodel, whatever)? I'm aware I might need to reflare and/or replace fittings on the lines.

How crazy would it be to run the lines through a small window and build a small box to mount the interior unit on? Of course building something out of wood or such to safely transition and seal the open window (I've done this for floor units with hoses as the included plastic stuff is usually garbage).

Or would I be better of spending the money on a window or floor unit heat pump. If so, which ones are worth getting? I'd actually prefer it didn't have resistive heat (or that it can be disabled).

I'm also looking for a 120V unit (regardless of type), I'm aware that limits the size.

Reasoning:

• We are not planning on staying here long term. I don't want to take the time to make the install "house selling friendly" beyond safety (GFI, properly rated wiring), and I'm not planning on converting the whole house.
• This specific room/area is somehow prone to extreme heat in summer and extreme cold in winter more than most of the rest of the house.
• Cooling needs of the rest of house are handled by existing window and floor units.
• Heating is central nat-gas, which grows more and more expensive, and supplemented with space heaters which (you guessed it) are getting more expensive to run
• replacing the heating system is not in the cards.
• The room in question is the worst offender for "excessive space heater use".
• AN absolute "base model" window AC is going to run say 200-300 anyways.
• my "back of the napkin" math puts savings at ~150 per year by replacing said space heater use

So to sum up my 3 key questions:
How easy/possible is it to move/reinstall minisplits
How insane is it to NOT drill holes in the wall and use a window (sealed sanely) as the passthrough?
If the above two are "just don't", whats a good window/floor heatpump?

One thing to remember is that heat pumps are good down to 32F. Below that, they don't work unless they have a built-in electric heater.

 

[whitedog]

One thing to remember is that heat pumps are good down to 32F. Below that, they don't work unless they have a built-in electric heater.

 

[Crowz]

Thats why I get the electric heater option on the mini splits I buy. I run ramsond units. Price wise they are not that cheap now compared to newer companies but I like them. I have 5 of them. They have the multi unit models too. The backup heat works pretty good.

 

[EastTexCowboy]

One thing to remember is that heat pumps are good down to 32F. Below that, they don't work unless they have a built-in electric heater.

The better ones go down to 5F or even lower, but much more expensive. Mine go to 5F which is plenty for where nm I live.