Air Source Heat Pump Project!

hikerjohnson · 08-26-13, 12:28 PM

So, a funny thing happened this past weekend; the girlfriend and I went to a local property in NH renowned for its gardens and sculptures that opens to the public every few years. It's truly phenomenal, and was well worth the half day spent wandering the grounds. Anyway.

On our way out, I passed a little hand printed sign on the barn door that said, Air conditioner: Best Offer, but the best offer was scratched out, and FREE written over it in crayon. I had to ask. So, I asked, and this is what followed me home!

It's a 3/4 ton EmeraldAire mini-split air conditioner, R-22 refrigerant!

(I have all the coverings, but the guts are the more interesting part, don't you think?)

FRONT

REVERSING VALVE

This is the interesting part: What self-respecting air conditioner has a reversing valve?

FRONT PLUMBING

SIDE PLUMBING

It's a SANYO!

I cracked the isolation valves, it's holding a charge of refrigerant! Woohoo!! That means my worst fear, that the compressor sat open to the elements for an unknown period of time, is unrealized. Provided the electronics work, I might even be able to hook this thing up just as it is!

CAP TUBE

You can see the thin black wire, that's what the schematic calls a Defrost Interface, but I'm not sure if the indoor unit hooks to it at all.

REAR PLUMBING

CIRCUIT DIAGRAM

DATA PLATE

More photos to follow as I open up the indoor half, and see what makes this tick, electrically speaking. Seems to me that this should be a very simple system to override and turn into a full-on reversible heat pump/AC unit. Possible uses include make-up heat for my basement, or better yet, a walk-in cold room for beer and root vegetable storage and flower keeping (girlfriend is a professional florist)

In a couple of weeks, I should have a good collection of HVACR tools including vacuum pump and manifold gauge - thread to follow as I document my own *NEW* mini-split installation.

Anyone have a suggestion of where to look for short lengths of copper ACR tubing? I balk at spending a ton of money to buy a lineset for a free mini-split just to play around. I sure don't need 50' of two sizes.

jeff5may · 08-26-13, 01:49 PM

Me want one! Me want one!

"What self-respecting air conditioner has a reversing valve?"
The kind that defrosts.

It looks like you have stumbled on another rebranded shinco unit. One ton rated capacity, not much different than the GE unit AC_HACKER is sitting on at present, trying to figure out how to integrate it into his ground-sourced system. If the indoor and outdoor units actually talk to each other, it will probably try to work. If you're lucky, the system will not be obstructed or leak, and will work like it should the first time.

I love that you took plenty of pics of the outdoor unit. This gives me a good idea on how to plumb my next monster. The one I hacked last year had vibration problems due to my "improperly" routed piping between the compressor and reversing valve. I now understand why the plumbing on these units looks like a "3D Pipes" screensaver: isolating vibration through multiple bends.

Good luck on your new-found orphan. I hope it serves you well.

Jeff

NiHaoMike · 08-26-13, 07:44 PM

It looks like the condensing unit is "dumb" and thus trivial to control with your own circuits.

BTW, the reversing valve appears to be line voltage rather than low voltage as is otherwise common. (It might be driven off an autotransformer or with a capacitive or resistive ballast, but Id be surprised.)

AC_Hacker · 08-26-13, 09:19 PM

Quote:

Originally Posted by hikerjohnson

So, a funny thing happened this past weekend...

It's just not natural for an EcoRenovator to just stumble upon the ideal unit for hacking... just not natural.

I think that your girlfriend is actually responsible here. She sounds like a keeper!

The unit you found looks like a keeper, too.

You can actually do a brief (no more than 5 seconds run time) test to see if your compressor is alive, without commissioning the unit...

When you have checked out everything you need to check out, and you're about to plug it in... be careful that you don't put a sustained load on a non-turning compressor.

If you have one, a Kill-a-Watt would be very useful at this point, but not required... read the whole procedure below.

When you plug it in, listen very carefully to any sounds... there's probably a time delay built in, so nothing may happen at all for the first 30 sec to 2 minutes. This would be normal, and during this time the unit will be very quiet, no buzz, no hum, nothing. Your Kill-a-Watt shouldn't show anything more than 20 or 30 watts... if that.

Then after the delay period, you should hear the compressor spin up... if it does (your Kill-a-Watt would read in excess of 400 watts), pull the plug within 5 secs max. You have won.

If it doesn't start up within 2 or 3 seconds look at your Kill-a-Watt, if you are seeing big watts, and NO compressor chugging and turning, pull the plug immediately.

If the compressor doesn't spring to life, it may be ruined (not too likely) or your starting capacitor may be dead. New ones are very cheap.

Best of luck!

-AC

NiHaoMike · 08-26-13, 10:34 PM

If the entire charge was stored in the unit, the compressor is almost surely good since it must be working to allow it to pump down. If they replaced it due to a bad compressor, they would have had to recover the charge.

While you're at it, put a new filter drier (bidirectional one for a heat pump!) on the liquid line. Ideally, you'll want to remove the old one, but given it's upstream of the service valve, it would take quite a bit of work. You can get away with it as long as the old drier isn't blocked. (If it is, you have some real problems with the system.)

Never test a heat pump unconnected. If it was set to heat and you turn on the compressor with the lines valved off, the pressure will build up to the point of something exploding.

hikerjohnson · 09-04-13, 10:15 AM

Hi folks, sorry for the delay in getting back here, lots of housework and a slowly failing wireless router have been making life interesting lately.

Today I cracked into the indoor unit a little bit, see it cover on, and more interestingly, cover off.

Looks pretty basic to me, though I am not prepared to start hacking into the circuit boards; they can stay where they are for the time being. In time I will get this all wired/plumbed up, and see what the lowest temp allowed by the firmware is, and then figure out how to override it.

I have a lead on some line set scraps, so I hope to be able to test-run this baby sometime soon. I have no idea if all the refrigerant was pumped down and back into the outdoor unit, or if there is just some residual refrigerant left in the compressor. I also wired up a 220 receptacle over my workbench so that I can get some power to the unit. Now I need an extension cord of some kind.

Notes to address previous posts:
No secondary cap tube to allow for heat pump mode, it’s just a hot gas defrost, like Jeff said. Also, the outdoor unit is all 110/220 VAC and is dumb. The indoor unit is obviously more complex, but seems to have real potential for a simple hacker like myself to be able to over-ride. The only fly in the ointment that occurs to me right now is how exactly to control the defrost cycle in an automatic sort of way.

Jeff, regarding the plumbing, don’t forget the little rubber baby buggy bumpers that are stuck onto the pipe loops. They definitely do a lot of vibration absorption. I’m thinking old-fashioned white gum erasers would probably work about perfectly, or something of about the same durometer.

AC_Hacker · 09-04-13, 11:16 AM

I'm really interested in what you''re doing here...

As you might know, I have a unit that is about the same era, different brand, different capacity, and mine is a heat pump (see: "AC Hacks A Heat Pump"). You are lucky in that you have both the outdoor part an the indoor part. I only have the indoor part, but I do have a schematic.

If I had the outdoor part, too, I'd more likely be able to decode the communications between the two, and be more able to make a controller that could talk to the existing outdoor unit.

As it is, my options are to use some of the outdoor controller, and 'roll-my-own' controller that could be the brains of the rest of the components. Else, I could build an entire controller from scratch. Acuario is building a controller for his unit, and I might be able to buy one of his controllers.

So, I guess what I'm getting at is that if you are able to learn anything about the communication between the indoor and outdoor units, it could be very helpful to me.

I mean, you could be an electronics wizard, with great wisdom regarding communications protocols and such.

Keep me in mind.

Best,

-AC_Hacker

hikerjohnson · 09-19-13, 09:24 AM

Quick update - I have been pressed with getting the fall harvest in from the vegetable garden and the hop vines, and also getting the utilities run for the big heat pump I am putting in. Indirectly, though, I have made progress on this - I wired in a 220V outlet over my workbench so that I will have a way to test run this bad boy.

Softly, slowly, catchy monkey.

Acuario · 09-20-13, 11:20 AM

I'm curious - why do you need 220V?
According to the data plate the unit needs 115V not 220V. Connect 220 and you'll possibly blow something.

hikerjohnson · 09-23-13, 09:18 AM

You know, Acuario, I don't know.

I hadn't looked at the data plates in some time, and I think I confused the heat pump I am installing for my house right now, which is 220V 20A feed, with this one, and made a little mental leap (incorrectly) that this needed 220V as well.

I guess I can play with this one now, as soon as I finish another 3,437 projects that are in line in front of it...

08-26-13, 12:28 PM	#1
hikerjohnson Submarine Renovator Join Date: Jul 2013 Location: Southern Maine Posts: 35 Thanks: 4 Thanked 5 Times in 5 Posts	Air Source Heat Pump Project! So, a funny thing happened this past weekend; the girlfriend and I went to a local property in NH renowned for its gardens and sculptures that opens to the public every few years. It's truly phenomenal, and was well worth the half day spent wandering the grounds. Anyway. On our way out, I passed a little hand printed sign on the barn door that said, Air conditioner: Best Offer, but the best offer was scratched out, and FREE written over it in crayon. I had to ask. So, I asked, and this is what followed me home! It's a 3/4 ton EmeraldAire mini-split air conditioner, R-22 refrigerant! (I have all the coverings, but the guts are the more interesting part, don't you think?) FRONT REVERSING VALVE This is the interesting part: What self-respecting air conditioner has a reversing valve? FRONT PLUMBING SIDE PLUMBING It's a SANYO! I cracked the isolation valves, it's holding a charge of refrigerant! Woohoo!! That means my worst fear, that the compressor sat open to the elements for an unknown period of time, is unrealized. Provided the electronics work, I might even be able to hook this thing up just as it is! CAP TUBE You can see the thin black wire, that's what the schematic calls a Defrost Interface, but I'm not sure if the indoor unit hooks to it at all. REAR PLUMBING CIRCUIT DIAGRAM DATA PLATE More photos to follow as I open up the indoor half, and see what makes this tick, electrically speaking. Seems to me that this should be a very simple system to override and turn into a full-on reversible heat pump/AC unit. Possible uses include make-up heat for my basement, or better yet, a walk-in cold room for beer and root vegetable storage and flower keeping (girlfriend is a professional florist) In a couple of weeks, I should have a good collection of HVACR tools including vacuum pump and manifold gauge - thread to follow as I document my own NEW mini-split installation. Anyone have a suggestion of where to look for short lengths of copper ACR tubing? I balk at spending a ton of money to buy a lineset for a free mini-split just to play around. I sure don't need 50' of two sizes.

08-26-13, 07:44 PM	#3
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	It looks like the condensing unit is "dumb" and thus trivial to control with your own circuits. BTW, the reversing valve appears to be line voltage rather than low voltage as is otherwise common. (It might be driven off an autotransformer or with a capacitive or resistive ballast, but Id be surprised.) __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

08-26-13, 10:34 PM	#5
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	If the entire charge was stored in the unit, the compressor is almost surely good since it must be working to allow it to pump down. If they replaced it due to a bad compressor, they would have had to recover the charge. While you're at it, put a new filter drier (bidirectional one for a heat pump!) on the liquid line. Ideally, you'll want to remove the old one, but given it's upstream of the service valve, it would take quite a bit of work. You can get away with it as long as the old drier isn't blocked. (If it is, you have some real problems with the system.) Never test a heat pump unconnected. If it was set to heat and you turn on the compressor with the lines valved off, the pressure will build up to the point of something exploding. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

09-04-13, 11:16 AM	#7
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	I'm really interested in what you''re doing here... As you might know, I have a unit that is about the same era, different brand, different capacity, and mine is a heat pump (see: "AC Hacks A Heat Pump"). You are lucky in that you have both the outdoor part an the indoor part. I only have the indoor part, but I do have a schematic. If I had the outdoor part, too, I'd more likely be able to decode the communications between the two, and be more able to make a controller that could talk to the existing outdoor unit. As it is, my options are to use some of the outdoor controller, and 'roll-my-own' controller that could be the brains of the rest of the components. Else, I could build an entire controller from scratch. Acuario is building a controller for his unit, and I might be able to buy one of his controllers. So, I guess what I'm getting at is that if you are able to learn anything about the communication between the indoor and outdoor units, it could be very helpful to me. I mean, you could be an electronics wizard, with great wisdom regarding communications protocols and such. Keep me in mind. Best, -AC_Hacker __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker...

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08-26-13, 01:49 PM	#2
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,428 Thanks: 431 Thanked 619 Times in 517 Posts	Me want one! Me want one! "What self-respecting air conditioner has a reversing valve?" The kind that defrosts. It looks like you have stumbled on another rebranded shinco unit. One ton rated capacity, not much different than the GE unit AC_HACKER is sitting on at present, trying to figure out how to integrate it into his ground-sourced system. If the indoor and outdoor units actually talk to each other, it will probably try to work. If you're lucky, the system will not be obstructed or leak, and will work like it should the first time. I love that you took plenty of pics of the outdoor unit. This gives me a good idea on how to plumb my next monster. The one I hacked last year had vibration problems due to my "improperly" routed piping between the compressor and reversing valve. I now understand why the plumbing on these units looks like a "3D Pipes" screensaver: isolating vibration through multiple bends. Good luck on your new-found orphan. I hope it serves you well. Jeff

09-04-13, 10:15 AM	#6
hikerjohnson Submarine Renovator Join Date: Jul 2013 Location: Southern Maine Posts: 35 Thanks: 4 Thanked 5 Times in 5 Posts	Hi folks, sorry for the delay in getting back here, lots of housework and a slowly failing wireless router have been making life interesting lately. Today I cracked into the indoor unit a little bit, see it cover on, and more interestingly, cover off. Looks pretty basic to me, though I am not prepared to start hacking into the circuit boards; they can stay where they are for the time being. In time I will get this all wired/plumbed up, and see what the lowest temp allowed by the firmware is, and then figure out how to override it. I have a lead on some line set scraps, so I hope to be able to test-run this baby sometime soon. I have no idea if all the refrigerant was pumped down and back into the outdoor unit, or if there is just some residual refrigerant left in the compressor. I also wired up a 220 receptacle over my workbench so that I can get some power to the unit. Now I need an extension cord of some kind. Notes to address previous posts: No secondary cap tube to allow for heat pump mode, it’s just a hot gas defrost, like Jeff said. Also, the outdoor unit is all 110/220 VAC and is dumb. The indoor unit is obviously more complex, but seems to have real potential for a simple hacker like myself to be able to over-ride. The only fly in the ointment that occurs to me right now is how exactly to control the defrost cycle in an automatic sort of way. Jeff, regarding the plumbing, don’t forget the little rubber baby buggy bumpers that are stuck onto the pipe loops. They definitely do a lot of vibration absorption. I’m thinking old-fashioned white gum erasers would probably work about perfectly, or something of about the same durometer.

09-19-13, 09:24 AM	#8
hikerjohnson Submarine Renovator Join Date: Jul 2013 Location: Southern Maine Posts: 35 Thanks: 4 Thanked 5 Times in 5 Posts	Quick update - I have been pressed with getting the fall harvest in from the vegetable garden and the hop vines, and also getting the utilities run for the big heat pump I am putting in. Indirectly, though, I have made progress on this - I wired in a 220V outlet over my workbench so that I will have a way to test run this bad boy. Softly, slowly, catchy monkey.

09-20-13, 11:20 AM	#9
Acuario Apprentice EcoRenovator Join Date: May 2011 Location: Tortosa, Spain Posts: 221 Thanks: 2 Thanked 81 Times in 46 Posts	I'm curious - why do you need 220V? According to the data plate the unit needs 115V not 220V. Connect 220 and you'll possibly blow something.

09-23-13, 09:18 AM	#10
hikerjohnson Submarine Renovator Join Date: Jul 2013 Location: Southern Maine Posts: 35 Thanks: 4 Thanked 5 Times in 5 Posts	You know, Acuario, I don't know. I hadn't looked at the data plates in some time, and I think I confused the heat pump I am installing for my house right now, which is 220V 20A feed, with this one, and made a little mental leap (incorrectly) that this needed 220V as well. I guess I can play with this one now, as soon as I finish another 3,437 projects that are in line in front of it...