Mini splits

[hidollartoys]

Was told recently that mini-split systems do not HEAT very well. It seems that due to there small physical size, there is very little room for supplemental strip heat to aid with heat pump operation. I know that they are great at cooling. The unit will be installed in a lake home in central Missouri.

Anyone care to comment???? (Foolish question)

 

[Rolling_Thunder]

I installed a Ramsond 18k BTU split heatpump with heat strip in March. And only used it once on a cold day it was like 43 out and it brought the temp up to 68 in about an hour in my 24x24 garage with the walls insulated but not the ceiling YET. The Heat Strip really doesnt come into effect until the temps drop below 20 degrees. So the Heat pump in a good insulated garage in your area should be sufficent. As far as cooling, I was in the garage all day Sunday it was 94 degrees and humid as hell out. I was nice and comfortable at 70 degree's in the garage!!

Heres the page for Ramsond's Split units:

http://www.ramsond.com/MiniSplitAir.php



Heres the one I bought:

http://www.ramsond.com/proddetail.php?prod=R55GW&cat=Ductless Mini Split AC Systems

These units are easy to install, come with everything and pre-charged. And runs on 220v with a 20amp circuit.

 

[ket-tek]

You can purchase most brands of mini-splits with or with-out backup heat strips.

As already mentioned, they Heat well until it gets below a certain temp, just like any heat pump. (mine are quoted at 19 degree's being the threshold temp, as I did not buy one with the heat strip option to save cost since it only gets that low a couple days a year around here.)

Buying them without a heat strip is just a money saving option. Buy one with a heat strip and you should have no issues.

Otherwise the main difference is that they are just ductless and only work well for large open spaces like a garage, loft, room in attic, or studio apartments. (unless you get into a multi-zoned system)

 

[46MGTC]

Can you truly install these yourself without the need for vacuum pumps, gauges, etc?
The Ramsond site implies that you do not need anything other than hand tools that does not ship with the unit.
Is this really true?

 

[A_Pmech]

Can you truly install these yourself without the need for vacuum pumps, gauges, etc?
The Ramsond site implies that you do not need anything other than hand tools that does not ship with the unit.
Is this really true?

You need a vacuum pump to pull down the line sets, along with a micronic vacuum gauge and a manifold set.

Here's a (rather lengthy) thread in my 3-unit split system, including drawing down the line sets:

http://www.garagejournal.com/forum/showthread.php?t=38775

 

[Rolling_Thunder]

Can you truly install these yourself without the need for vacuum pumps, gauges, etc?
The Ramsond site implies that you do not need anything other than hand tools that does not ship with the unit.
Is this really true?

I wondered about that also. The supplied instructions say to put a vacuum on it I called their Tech Support they said hook it all up and turn it on no vacuum needed. Thats what I did and it works fine

 

[wtfovr]

I wondered about that also. The supplied instructions say to put a vacuum on it I called their Tech Support they said hook it all up and turn it on no vacuum needed. Thats what I did and it works fine

How long have you been running your system like that, not pulling a vacuum? I would love to not have to pay a a/c guy $200 to pull a vacuum and turn on a valve.

 

[thammel]

I guess most of us have manifold sets for charging our car AC units. I do. I bought adaptors for connecting to the newer non r-12 type. Here's a trick I did to actually make a vacuum pump. It's been probably 25 years but way back then when I was young and without any $$ and starting the young family I saw plans to make an air compressor in Popular Mechanics. So I did it - bought a used 1 hp motor, bought an air tank from Grainger and found a used air comditioning compressor from a car (think a Volvo) and I think it's a York brand compressor. Anyway, the trick was to plumb a line to the intake with a valve so you can connect a line to the intake of the air compressor and its suction creates a great vacuum. The valve closes off the opening of the line to the air. I've used this to evacuate air conditioning systems when replacing lines - it works great!

As an aside, in roughly 1979 or so I installed central air in my first house that only had a gas fired forced air furnace. I bought a system from Sears and it came with a pre-charged lineset. There was no need for evacuating anything and things worked pretty well. I remember kinking the line a little bit and agonizing over whether that affected performance. I also recall worrying about getting a good seal. That would be one good reason for evacuating - watching the vacuum gauge to see that all connections were tight.

Tom

 

[Rolling_Thunder]

How long have you been running your system like that, not pulling a vacuum? I would love to not have to pay a a/c guy $200 to pull a vacuum and turn on a valve.

Since March of this year

 

[Vicegrip]

old time dirty trick is to purge the lines with some refrigerant. Back in the pre EPA days this was almost SOP.
The newer split units are filled with non ozone depleting gas so a purge would hurt nothing laws aside. I do not advocate breaking any laws or hurting the environment.

How some guys used to do it before it was illegal. Hook up the line set and leave one side threaded on but loose.
Burp some charge down the line, through the evaporator and back out through the cracked fitting. Most pre-charged systems are charged for up to X number of feet of line set. If you are well under that lenght a small purge of harmless non ozone depleting gas will not reduce system peformance. The key is getting al the non condensable gasses out. Moisture is not a real problem as the system runs above 32 deg and the systems almost always come with good size filter dryers built in to compensate for the abuses (such as the above) seen in field installations. Once you purge close the fitting and shut the system valve after some pressure has built up. Look for leaks and open both system valves if none are found.

 

[TheShrine]

Can you truly install these yourself without the need for vacuum pumps, gauges, etc?
The Ramsond site implies that you do not need anything other than hand tools that does not ship with the unit.
Is this really true?

I installed two splits in my garage and I was told the same thing. The only caveat was if I did it myself, and not a certified installer, it was not warrantied!

Makes sense........

 

[Vicegrip]

If you don't remove any non condensable gasses you will reduce the performance of the system. A deep vacuum is best but you should do something to get as much air and moisture out of the lines and evaporator.

 

[XR80David]

Was told recently that mini-split systems do not HEAT very well. It seems that due to there small physical size, there is very little room for supplemental strip heat to aid with heat pump operation. I know that they are great at cooling. The unit will be installed in a lake home in central Missouri.

Anyone care to comment???? (Foolish question)

They may not heat well but they do cool well! I have had my Mitsubishi Mr. Slim for at least 18 years now and it works great. The heating is not that great, your right. But hey, it's on my garage I don't want to be warm/hot in there anyways!

 

[hidollartoys]

First let me restate that this unit will be in a lake house, not a garage.

I take it that these units do not heat well unless you spring for the strip heat, which I plan to do.

Has anyone used one of these units in a living area and had good luck with the heating?

 

[Vicegrip]

Mine heat far better than direct elec heaters of the same wattage. a heat strip is just resistance heat and is the most expensive form of heat most of the time. The older heat pumps did not work as well as the new ones do. 20 deg outside temps and both still blow warm air and maintain the temps in the conditioned space.

 

[79firebird]

heating on them worked fine for me in the winter with out the heat strips n prob. You can install your self yes with out a ac guy IF you get the precharged linesets for it is what the local ac compeny told me when i got mine from them. I could have installed them my self but i got them to do it. they live 3 doors down and did it after work for a case o beer.

 

[Todd.Brock]

Hey all,

Sorry if this is a thread hi jack... I have a 10 year old 2 story home. So if my central air ***** *** on the second floor of my house with vaulted ceilings, is this the answer?? The side that the condensor unit ifor the centrail a/c ss currently on is in the same side as the house where the master bedroom is. Are these pretty simple to install?? Does the whole interior unit mount to the wall? Do you have to cut a hole large enough just for the refrigerant lines? The price isnt too bad considering...

 

[79firebird]

Yes the indor unit mounts on the wall you you need about a 2inch hole in the wall to run all the lines out. And yes there simple to install.