Hello, I am investigating the possibility of installing a ductless split AC system in my small apartment (665 sq ft).
My question is whether the "outside" unit of the split system needs to be outside or on a roof? Can it be in the utility closet which currently houses the furnace and water heater?
thank you for any feedback, Jason.
Yes the condenser must go outside. Location to be determined by the unit and installation needs. Other wise your just moving the heat from one room to another instead of removing it.
the outside unit must be outside to work correctly, but a roof is OK
also, it needs to be out of direct sunlight if possible, you will save a lot of money if it is in shade, so I would consider a little hut over it, if mounting on the roof, just make sure that the unit has plenty of space on all sides and on top, at least 2' all around, and the airflow around it is not restricted by the "hut"
natural shade is fine too, such as from a tree or neighboring high-rise building
cheers!
cowboy
Hi cowboy, hope you are having a nice day
On 28-Jun-05 At About 09:08:29, cowboy wrote to All Subject: Re: ductless split A/C system
c> From: "cowboy"
c> the outside unit must be outside to work correctly, but a roof is OK
c> also, it needs to be out of direct sunlight if possible, you will c> save a lot of money if it is in shade, so
I don't know where you get your info but shade doesn't matter.
c> I would consider a little c> hut over it,
not needed.
-=> HvacTech2
actually shade matters a lot in your utility bill, that is why I said it would cost less.
I will explain the physics of it:
how hard the compressor has to work is proportional to the head pressure it is up against, and a shaded condenser is cooler, and therefore has a lower head pressure at the same ambient temperature, not to mention that the final temperature out the ducts will also be lower, which will allow the unit to stay off for a longer period of time, even further saving money.
so the long and short of it is, a unit will work just fine in full sun, but it will work a lot cheaper in shade
in wintertime, a heat pump would work a little better in sun than in shade, but not nearly enough to offset the summer saving, not even close.
cheers!
cowboy hvac engineer & tech
Hi cowboy, hope you are having a nice day
On 28-Jun-05 At About 10:11:03, cowboy wrote to All Subject: Re: ductless split A/C system
c> From: "cowboy"
c> actually shade matters a lot in your utility bill, that is why I said c> it would cost less.
As I said before, you are mistaken. the air over the condenser coil keeps it cool even with the sun on it. sunlight has a very minute influence on the head pressure. please get some training somewhere before you try to answer these questions. you really do need it.
-=> HvacTech2
you are really embarrassing yourself in front of everyone, this point is not even debatable!
you don't get to defy basic science, no matter how clueless you are!
if you really believe this (because you have never had a class in basic thermodynamics, and are basically just a stupid redneck with a GED) you can easily prove it to yourself by doing a simple experiment that even YOU can understand!
hook a clamp on ammeter around the unit's lead-in, measure current draw after running unit in the sun for an hour in the hot part of the day, then shade condenser and measure in another hour (make sure that the ambient temp outside is the same in both cases)
you will see a significant difference in energy consumption!
here is a good book:
please do us a favor and read it, you look like a horse's ass to the engineers and scientists that lurk on this board!
cheers!
cowboy
Hi cowboy, hope you are having a nice day
On 28-Jun-05 At About 11:51:28, cowboy wrote to All Subject: Re: ductless split A/C system
c> From: "cowboy"
c>> actually shade matters a lot in your utility bill, that is why I said c>> it would cost less.
c> you are really embarrassing yourself in front of everyone, this point c> is not even debatable!
c> you don't get to defy basic science, no matter how clueless you are!
c> if you really believe this (because you have never had a class in c> basic thermodynamics, and are basically just a stupid redneck with a c> GED) you can easily prove it to yourself by doing a simple c> experiment that even YOU can understand!
c> hook a clamp on ammeter around the unit's lead-in, measure current c> draw after running unit in the sun for an hour in the hot part of c> the day, then shade condenser and measure in another hour (make sure c> that the ambient temp outside is the same in both cases)
c> you will see a significant difference in energy consumption!
c> here is a good book: c>
c> please do us a favor and read it, you look like a horse's ass to the c> engineers and scientists that lurk on this board!
So clueless. you really need to buy and read these books you keep referring to. :)
-=> HvacTech2
Cowboy, look in he mirror, you are mistaken on who should be embarrassed! It does little good to shade a condensing unit. It is much more important to make sure the unit is placed where it will get a good unrestricted flow of air. Placing a "hut" over it is just asking for trouble. Greg
Hi Greg, hope you are having a nice day
On 28-Jun-05 At About 10:47:18, Greg O wrote to All Subject: Re: ductless split A/C system
GO> From: "Greg O"
GO> Cowboy, look in he mirror, you are mistaken on who should be GO> embarrassed! It does little good to shade a condensing unit. It is GO> much more important to make sure the unit is placed where it will get GO> a good unrestricted flow of air. Placing a "hut" over it is just GO> asking for trouble. Greg
It doesn't do any good to try to explain anything to this guy. he thinks he is right even when you show him in black and white that he is wrong. it is guys like Meehan and this one that cause homeowners more problems than they started with by handing out wrong info which causes more damage to the equipment then when they started.
-=> HvacTech2
You don't even have a clue...
It is funny that there three guys in these thread alone that called him out, but I am sure he believes he is still right! He is living in his on little Utopia! Greg
Cowboy,
While there is a VERY SLIGHT energy savings from shading the outdoor unit, the cost of building the hut over the onit will exceed the energy savings over a long time. The payback is likely to exceed 10 years, depending on construction costs and local energy rates. Look at how much heat is rejected to the air vs how much solar gain you get. The solar gain is a very small percentage of the heat rejected. Just figure the heat input from the sun is about the same as the solar gain for a like sized single pane window. Also consider that any shelter you erect is going to restict air flow some or cause air recirculation. Either will reduce efficiency of the system, possibly more than the savings from reduced solar gain. Cowboy, you are just spitting in the wind. Are you possibly related to Nick at Villanova? You sound a lot like him!
Stretch
Stretch
sorry guys, but just because the majority have the same opinion, that doesn't mean its not wrong!
if you doubt that, look at the election last November, the idiot "majority" elected the worst president of my lifetime
sometimes you have to pay the price for your mistakes
and some people will never learn!
We won't see too much more of him. He's running with his tail between his legs...
Right. Jimmy Carter was before your time?
Whether we have the correct president or not, is an opinion. Many people would disagree with you on that opinion.. The drivel you throw out as facts is easily proved wrong. Two very different things. Greg
are you on crack?
I am one of the most prolific posters on this board
I just get tired of re-explaining the same basic HVAC 101 concepts to idiots who think they know everything and actually know very little.
once I have explained the physics or thermodynamics or just a basic concept to a dumb redneck who is working on his GED, and he still doesn't get it, and refuses to buy any books, etc, and help himself, that is really all I can do.
I believe there is a word that describes those of you that suffer from this affliction. the word is CLUELESS!
Why would he be running? He is a legend in his own mind! Greg
I posted this > I'd have to dig around for a link. But someone posted a couple months back a
Is this the study?
That study doesn't seem to agree with your position. I'm not arguing the thermodynamic principals, just pointing out that an unbiased, highly regarded authority in the energy field did a real life study over a couple of years and found negligible difference between shaded and unshaded condensors. How do you explain that?
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