Sanyo 24KHS72 AC/HP DIY install project - Page 34

Xringer · 02-28-11, 04:31 PM

Well, I've been trying to dig up more info about T-Run. If I find encouraging info,
I will be very interested in repairing the leak in my spare unit.

Once repaired and pressure tested, I should be able to hook it to a simple
makeshift exchanger, add some lube and Propane to see if the unit will perform
a sustained run, after triggered by a T-Run button/or switch.

If it will Pump Heat and not quickly time out, then I can decided how to deploy the unit..

A Hot water source would really cut down our oil use. That would seem to be the best way to go.

I would need a new slab and power drop for the unit. But the rest could be fun..

Dang, I should have made this stab bigger!!

(This is a pic of the leaky unit).

AC_Hacker · 03-01-11, 01:14 AM

Quote:

Originally Posted by Xringer

I was just thinking. If I hauled that outdoor unit down to my basement and ran a line-set loop outdoors,
to a heat exchanger down in a well (sitting in 50 deg water).?.

Maybe I could heat my Basement?
Or dehumidify & cool it during the summer?

I think that if I were looking into something like this, I'd forget the line-set thing and try to figure a way to put the proper sized Brazed Plate heat exchanger inside of or fastened to the outside unit box. Then it would be easy and flexible to change configuration.

Also, I don't know how deep your well is, or how much flow through your well you have, but I'm finding out from my little heat pump, that there is a limit to how much heat you can withdraw. You really won't know until you try.

Xringer, this sounds like a really great project... one that's just waiting to be done.

I think that one snag might be that the inside unit may have significant electronics or valving that could throw you a curve. Maybe you could link to the schematics in your thread and someone here could go over them to look for possible problems.

If this is not the case, you are standing in the clear.

This project (re-purposing an ASHP mini-split to Air-in, Water-out) just might want it's own thread, too.

I think you are really on to something here... this could go really big.

-AC_Hacker

MN Renovator · 03-01-11, 04:19 AM

About six months ago I ran into Youtube videos of an Austrailian guy who works on A/C mechanicals and takes apart compressors and stuff like that. He has a video where he was showing mini-split units and he was talking about using one(non-inverter R22) with his home central air system. He didn't discuss efficiency which might be an issue for a system with non-match components and would require a TXV for sure with enough flow in the evaporator end but I don't see why this sort of thing wouldn't work.

Like AC_Hacker said, if you are going to water or ground source a unit, be sure you have enough source thermal capacity.

With propane, it could be tricky to maintain ideal pressures in the system, is the R410 oil compatible with propane? It would be cool to see your plans working out.

I had a weird dream with the condenser in the basement and the electronics of the evap inside but the lines running to ground source and then running cool to heat and heat in order to cool(since both sides of the unit are reversed) ...weird waking up from such a dream, I might need to have my head checked for dreaming about HVAC.

Xringer · 03-01-11, 10:23 AM

I like the idea of a 'Brazed Plate heat exchanger'. I was looking at some on Ebay last night.

I don't have a well dug yet, but it's a project on my list.
The backyard borders on a swamp, fed from a pond, 70 yards away.
If it's not made illegal, I would like to be able to water my plants etc.
(Water rates are due to skyrocket here).

Snags:
I'm pretty sure the indoor plumbing is just a plain coil, nothing fancy.
The small control board seems to regulate the fan & it's venting direction,
monitor temperatures & the T-stat.
Mostly, I think it just passes simple commands to the outdoor unit.
Mode, start-run & idle-run. And, it can read back outdoor status/problems.

I think (and hope) most of the brains are in the outdoor board.
I hope it handles defrosting & etc on it's own.

Maybe, I can operate the outdoor unit in test mode.
If it just comes on and runs at 1/2 speed, that would be sweet.
Hopefully, it would still monitor it's own sensors and not go into
destructive runaway mode.

After the repair, I'll rig up some testing. If it looks ok, I'll proceed with
a hotwater project. If not, I'll have a fully functioning spare unit,
that I can install quickly. Just in case.

I'm studying propane. So far, it looks good. I'll keep digging.
I'm sure the POE lube in the system now is full of water, due to the leak hole.
It will need to be cleaned out. New lube to match the refrigerant will have to be added..

I'll start a new thread for this topic..

Thanks,
Rich

AC_Hacker · 03-01-11, 10:37 AM

Quote:

Originally Posted by MN Renovator

...weird waking up from such a dream, I might need to have my head checked for dreaming about HVAC.

MN Renovator,

This is pretty serious.

I think you are standing at the door to insanity, but with some help, we can pull you through.

-AC_Hacker

MN Renovator · 03-02-11, 07:56 AM

Quote:

Originally Posted by AC_Hacker

MN Renovator,

This is pretty serious.

I think you are standing at the door to insanity, but with some help, we can pull you through.

-AC_Hacker

Xringer · 03-06-11, 11:47 AM

It was 58F (been mild for the last 24 hours) outdoors, 70F indoors.
Vacuumed the hoses, shut out the pump and started watching the readings.
System had been running at under 500w (off&on) for the last 24 hours.

Start: 410 PSI @ 480w. Waited 5 minutes.
Turned up the setpoint to 22C and got 1.6kw and 415 PSI.
5 Minutes later, at 740 watts, the pressure dropped to 340 PSI.
After shutting off the system, the 'resting' pressure was 260 PSI.

Here's some readings from Dec 14, 2009:
This was a few weeks before that first system leaked and crashed.

Today wasn't too cold, so we measured the pressures.
Pressure was measured at Wide Tube Service valve.

Outdoor temp 43 degs F,
Indoor temp 68 to 70 degs F.

System off for 25 minutes, pressure = 140 PSI

Heating & using 1.5 kW, pressure = 375 PSI
Heating & using 2.0 kW, pressure = 450 PSI
Heating & using 2.15 kW, pressure = 460 PSI

Cooling & using 0.480 kW, pressure = 110 PSI
Cooling & using 0.90 kW, pressure = 105 PSI

MN Renovator · 03-07-11, 03:53 PM

Why did you only set the setpoint to 22C? Pressure readings, from my understanding are supposed to be measured under full load. You are two amps short of your operating current chart, if raising the setpoint another degree raises the amperage to the roughly 8.5 amps or so versus the <7 amps you are pulling at a standard room temp setpoint you aren't going to have full pressure at a lower load.

From the other thread you were talking about power consumption and temperature. The lack of capacity is what was reducing the power usage at full load on the chart, the unit reduces its capacity(if demand exists to bring an inverter unit to maximum capacity) more than what it could possibly otherwise produce in order to maintain decent efficiency and retain valid pressures to prevent undesired things compressing refrigerant to the point of liquid going back through the compressor, which is no good. So basically the unit ramps itself down when it knows it can't pull adequate heat out of the outdoor air. You aren't at maximum demand on your unit, so you aren't pulling maximum power for that temperature, and likely short on the pressure to make such a diagnostic measure to determine there is a problem.

I think your unit might be doing okay. ...at least until you crank it to maximum capacity and make the measurement then. ...but then again you are convinced the high kw spike in power is what caused the leak in your first one so I'm not sure if you even want to test it.

Typically you know an A/C unit is low on refrigerant if you run the unit and it freezes the evaporator even with the blower on full speed and the evaporator is clean. It might be a bit cold outside to run such a test though and I'm not sure if there are any pressure checks in the outdoor unit that might cut back output if it thinks it might be freezing the evaporator.

Xringer · 03-07-11, 04:18 PM

I set it to 22C, because the house was at about 21C. If I called for 25C or hit
the High-Power button, the power use would start increasing in 10-20 watt steps
every second or two, until the system was drawing around 3,600 watts.
(The max it should use is about 2,600 watts)..

I'm trying to prevent the system from going into over-load, since I think it's not good for the life of the system.
I suspect the old outdoor unit failed after it ran up to 3,600 watts too many times.

One of the problems I'm having with the system is the 3.6kW surge after each defrost cycle.

I'm dealing with the problem. I have an alarm that beeps me awake at 1kW.
I shut down the system and re-start it. (Sometimes at 3AM).
It's the only way I have found to by-pass the "Instant High Heat" part of the control program.

Xringer · 03-07-11, 04:19 PM

In order to get more sleep, I'm considering building a current(amps) programmable 220v circuit breaker.
It would shut of power to the Sanyo if it went above 2,600 watts,
And then automatically reconnect the 220, re-powering the unit.
It would simulate a grid failure, which the Sanyo should be programmed to handle.

I have the current sensor, I just need a 220vac SSR..

03-06-11, 11:47 AM	#337
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 115 Thanked 250 Times in 230 Posts	Pressure test today. Does not look good. It was 58F (been mild for the last 24 hours) outdoors, 70F indoors. Vacuumed the hoses, shut out the pump and started watching the readings. System had been running at under 500w (off&on) for the last 24 hours. Start: 410 PSI @ 480w. Waited 5 minutes. Turned up the setpoint to 22C and got 1.6kw and 415 PSI. 5 Minutes later, at 740 watts, the pressure dropped to 340 PSI. After shutting off the system, the 'resting' pressure was 260 PSI. Here's some readings from Dec 14, 2009: This was a few weeks before that first system leaked and crashed. Today wasn't too cold, so we measured the pressures. Pressure was measured at Wide Tube Service valve. Outdoor temp 43 degs F, Indoor temp 68 to 70 degs F. System off for 25 minutes, pressure = 140 PSI Heating & using 1.5 kW, pressure = 375 PSI Heating & using 2.0 kW, pressure = 450 PSI Heating & using 2.15 kW, pressure = 460 PSI Cooling & using 0.480 kW, pressure = 110 PSI Cooling & using 0.90 kW, pressure = 105 PSI Last edited by Xringer; 03-06-11 at 02:07 PM.. Reason: Adding notes:

03-07-11, 03:53 PM	#338
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 940 Thanks: 41 Thanked 117 Times in 91 Posts	Why did you only set the setpoint to 22C? Pressure readings, from my understanding are supposed to be measured under full load. You are two amps short of your operating current chart, if raising the setpoint another degree raises the amperage to the roughly 8.5 amps or so versus the <7 amps you are pulling at a standard room temp setpoint you aren't going to have full pressure at a lower load. From the other thread you were talking about power consumption and temperature. The lack of capacity is what was reducing the power usage at full load on the chart, the unit reduces its capacity(if demand exists to bring an inverter unit to maximum capacity) more than what it could possibly otherwise produce in order to maintain decent efficiency and retain valid pressures to prevent undesired things compressing refrigerant to the point of liquid going back through the compressor, which is no good. So basically the unit ramps itself down when it knows it can't pull adequate heat out of the outdoor air. You aren't at maximum demand on your unit, so you aren't pulling maximum power for that temperature, and likely short on the pressure to make such a diagnostic measure to determine there is a problem. I think your unit might be doing okay. ...at least until you crank it to maximum capacity and make the measurement then. ...but then again you are convinced the high kw spike in power is what caused the leak in your first one so I'm not sure if you even want to test it. Typically you know an A/C unit is low on refrigerant if you run the unit and it freezes the evaporator even with the blower on full speed and the evaporator is clean. It might be a bit cold outside to run such a test though and I'm not sure if there are any pressure checks in the outdoor unit that might cut back output if it thinks it might be freezing the evaporator. Last edited by MN Renovator; 03-07-11 at 03:57 PM..

02-28-11, 04:31 PM	#331
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 115 Thanked 250 Times in 230 Posts	Well, I've been trying to dig up more info about T-Run. If I find encouraging info, I will be very interested in repairing the leak in my spare unit. Once repaired and pressure tested, I should be able to hook it to a simple makeshift exchanger, add some lube and Propane to see if the unit will perform a sustained run, after triggered by a T-Run button/or switch. If it will Pump Heat and not quickly time out, then I can decided how to deploy the unit.. A Hot water source would really cut down our oil use. That would seem to be the best way to go. I would need a new slab and power drop for the unit. But the rest could be fun.. Dang, I should have made this stab bigger!! (This is a pic of the leaky unit).

03-01-11, 04:19 AM	#333
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 940 Thanks: 41 Thanked 117 Times in 91 Posts	About six months ago I ran into Youtube videos of an Austrailian guy who works on A/C mechanicals and takes apart compressors and stuff like that. He has a video where he was showing mini-split units and he was talking about using one(non-inverter R22) with his home central air system. He didn't discuss efficiency which might be an issue for a system with non-match components and would require a TXV for sure with enough flow in the evaporator end but I don't see why this sort of thing wouldn't work. Like AC_Hacker said, if you are going to water or ground source a unit, be sure you have enough source thermal capacity. With propane, it could be tricky to maintain ideal pressures in the system, is the R410 oil compatible with propane? It would be cool to see your plans working out. I had a weird dream with the condenser in the basement and the electronics of the evap inside but the lines running to ground source and then running cool to heat and heat in order to cool(since both sides of the unit are reversed) ...weird waking up from such a dream, I might need to have my head checked for dreaming about HVAC.

03-01-11, 10:23 AM	#334
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 115 Thanked 250 Times in 230 Posts	I like the idea of a 'Brazed Plate heat exchanger'. I was looking at some on Ebay last night. I don't have a well dug yet, but it's a project on my list. The backyard borders on a swamp, fed from a pond, 70 yards away. If it's not made illegal, I would like to be able to water my plants etc. (Water rates are due to skyrocket here). Snags: I'm pretty sure the indoor plumbing is just a plain coil, nothing fancy. The small control board seems to regulate the fan & it's venting direction, monitor temperatures & the T-stat. Mostly, I think it just passes simple commands to the outdoor unit. Mode, start-run & idle-run. And, it can read back outdoor status/problems. I think (and hope) most of the brains are in the outdoor board. I hope it handles defrosting & etc on it's own. Maybe, I can operate the outdoor unit in test mode. If it just comes on and runs at 1/2 speed, that would be sweet. Hopefully, it would still monitor it's own sensors and not go into destructive runaway mode. After the repair, I'll rig up some testing. If it looks ok, I'll proceed with a hotwater project. If not, I'll have a fully functioning spare unit, that I can install quickly. Just in case. I'm studying propane. So far, it looks good. I'll keep digging. I'm sure the POE lube in the system now is full of water, due to the leak hole. It will need to be cleaned out. New lube to match the refrigerant will have to be added.. I'll start a new thread for this topic.. Thanks, Rich

03-07-11, 04:18 PM	#339
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 115 Thanked 250 Times in 230 Posts	I set it to 22C, because the house was at about 21C. If I called for 25C or hit the High-Power button, the power use would start increasing in 10-20 watt steps every second or two, until the system was drawing around 3,600 watts. (The max it should use is about 2,600 watts).. I'm trying to prevent the system from going into over-load, since I think it's not good for the life of the system. I suspect the old outdoor unit failed after it ran up to 3,600 watts too many times. One of the problems I'm having with the system is the 3.6kW surge after each defrost cycle. I'm dealing with the problem. I have an alarm that beeps me awake at 1kW. I shut down the system and re-start it. (Sometimes at 3AM). It's the only way I have found to by-pass the "Instant High Heat" part of the control program.

03-07-11, 04:19 PM	#340
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 115 Thanked 250 Times in 230 Posts	In order to get more sleep, I'm considering building a current(amps) programmable 220v circuit breaker. It would shut of power to the Sanyo if it went above 2,600 watts, And then automatically reconnect the 220, re-powering the unit. It would simulate a grid failure, which the Sanyo should be programmed to handle. I have the current sensor, I just need a 220vac SSR..