Prior to opening up this can of worms, I did some ebay shopping. The stuff I picked up:

RANCO V3 REVERSING VALVE/LESS COIL - $12.00
JARD TRANSFORMER, PRIMARY VOLT:120, SECONDARY VOLT:24, VA:20 - $5.00
Ranco Invensys L30-83 Solenoid Coil 24 VDC for V1-V12 Reversing Valve - $5.00

Robertshaw 300-201 1 heat/ 1 cool digital thermostat - $1.05
(EDIT: This thermostat will be replaced with a HEAT PUMP THERMOSTAT since it makes the unit short-cycle in heating mode under certain conditions.)

ICM 315 Defrost Control Board works on any brand heatpump FREE SHIPPING - $3.75 and it comes with a thermistor!

I'll be looking for a txv the right size to replace the 3/4 ton one I harvest from this unit...
But guess what? I might be able to use aforementioned txv in the other unit! Maybe...

For now, I've got questions.

1. The reversing valve I scored is rated at 3 tons max. Will it work with my 1 1/4 ton compressor? If not, what can I do to help it work?
2. What is the best practice in plumbing a reversing valve? Special routing of piping, etc.
3. Should I even bother with a txv? The unit has 2 short cap tubes... how much would I gain going txv on the outside coil versus leaving the cap tubes? I would like to get down below freezing on this unit. The txv I just found in this unit is rated to -40*f.

For now, I'll be waiting for my items to ship. Meanwhile, I'll figure out how to wire this beast with what's coming soon.

This model Sanyo has bad programing (IMHO) and my first unit lost it's R410A.
If you aren't watching them closely, these things will over-load/over-pressure and pop an artery.

Sanyo sent me a new outdoor unit (on warranty) and didn't want the broken one back.
I was able to repair it (no warranty) and ordered a new indoor unit for it.
So, it was a pretty good deal for a second 24k cooling / 36k heating system.

I considered using the 'spare' for hot water too, but now that I've got the
AirTap A7 ASHP hot water heater, I'm glad I didn't mess with a Sanyo.
The AirTap uses very little power and I can get hot water, even when
I don't need cooling or heating running.. (like today).
Since I was burning oil for hotwater before, I might be at breakeven by next fall.
(Depending on fuel oil prices).. :eek:

Good Luck with your surgery doctor! :D

I think it'll work just fine. It is desirable to keep your refrigerant/oil velocity higher than some minimum level. Too fast and you suffer friction losses, too slow and you risk having your lubricant not staying in suspension properly. In your case just having a short piece of too-big tube will not be a problem.

I'm not qualified to answer that. You might try asking at the HVAC TALK forum. But be forewarned that if they think you are a DIY guy, they may not talk to you.

Your primary advantage is adjustability.

When you say, "get down below freezing on this unit", I assume you mean that you want to be able to pull energy from the air, when the air temperatures are lower than 32 F. The lower threshold is more likely a function of your refrigerant. If you're using R22 or R290, you can probably 'get below freezing', but not a whole lot more.

Hope this has helped.

Best Luck,

-AC

BTW, I suspect that your weakest link will be the size of your evaporator coil (the part that gets cold and draws heat from the outside air) and also the amount of air your fan will be able to push through the evaporator... but soldier on, brother. You're going to learn a lot and my hunch is that your unit actually will provide you with useful, economic heat. But it can always be improved upon.

BTW#2, what is the character of the soil in your area? What kind of problems do well drillers have there in KY, where you are?

parts trickling in
 

Xringer, how does Sanyo get away with 50 percent more heating than cooling? Just wondering.sounds like a capitol one ad: 50 percent more heat, what's in your wallet?

AC, the city I live in sits atop extreme karst.rocky red clay for a few feet, then limestone and shale.mammoth cave state park is 50 miles South of me.my parents have a sinkhole that has an artesian spring draining into it's mouth.my kids call it the bat cave.I'm also renting, so drilling up the yard is out. I have a portable AC unit like the one you got from the girl (yikes) that I ran like xringer showed in his window, blowing cold air outside.it worked awesome last winter! Can you show some pics of its guts and plumbing for me please, if you still have it? That thing saved me 400 bucks or more over natural gas.

I believe I've concocted a control scheme for the unit while waiting on parts to come in. I'm using a non heat pump thermostat, doh! maybe next time...waddya expect for cheap? Here goes, all you engineers feel free to scrutinize my idea and save me some trouble, I'd appreciate any input.

http://i1326.photobucket.com/albums/...pse5099f38.jpgSorry, but I'm not a computer illustrator.

Main idea is this:

1. I want to be able to set it and forget it (in theory).
2. As few parts as possible (less is more).
3. Auto-defrost in heat and cool modes.

Basic operation:

w1 - heating - starts timer in heating defrost control
y1 - cooling - energizes reversing valve
g - energizes fan contactor thru defrost relay and compressor thru cooling defrost klixon (bimetal thermostat - opens at 20*f, closes at 50*f)

It all depends on the outdoor temperature
 

As you can see from this chart, if it's pretty mild outdoors, you can get a lot of BTUhs..

http://i46.photobucket.com/albums/f1...CL/heatcap.jpg

Here's the basic spec sheet.
http://i46.photobucket.com/albums/f1...L/poweruse.jpg


The truth is, I have no idea of the actual BTUhs that are being pumped,
I'm just going by the room temperature. These things can keep the house
nice and warm, and don't use a lot of KWhs. :cool:

We've been using them off and on, for the last few weeks. The heating season has arrived. :(

Wondered about why more heating than cooling.?. It seems weird..
Maybe it has to do with HX coil size. When the larger(outdoor) HX is absorbing heat, instead of dumping it, maybe it works better.?.

"how does Sanyo get away with 50 percent more heating than cooling?"

It isn't uncommon for an inverter mini-split to run at a higher RPM heating than cooling.
The spec sheet from the Carrier 25VNA central air inverter 36k heat pump runs the compressor at 1800-4500RPM for cooling but when heating it will 6850 at 44 degrees F with a full duty call for heat and the spec sheet says if the outdoor temperature is right it can even spin at 7000RPM. If you run the unit at 0f it's likely running full bore as long as there isn't a call for aux heat that might otherwise drive it down or shut it off.

Heat Capacity: Water Furnace assumes that in addition to the heat extracted from the source water loop, the electrical energy consumed by the heat pump is also converted into heat and fed into the load fluid

Geothermal Water Heating Efficiency study (Second cut).

I found this explanation on the our cool house web site.

charlesfl

You could be on the right track with higher RPMs while heating.
When we click up 1 deg C on the remote, there is an unnecessarily large ramp-up in power.

IMHO that big ramp-up comes from Sanyo's marketing dept..
The must believe that we want an 'instant' burst of heat,
instead of a slow steady increase in heat (saving some power).

This morning, it looks like our stupid Sanyo control firmware took off for the moon..
Popped the 10A breaker when my wife clicked up the remote from 20 to 21C.


http://ecorenovator.org/forum/attach...1&d=1351256353
The peak power use for the month happened today at 2.52kW.

2,520w / 10a = 252 volts this morning, when she hit the button..


As you can see, since 3:05 AM this morning, the line voltage has been bouncing up and down about 29 volts.
(which is 58v on the 230 pair).
http://ecorenovator.org/forum/attach...1&d=1351256310

My guess: When we get high line voltage (250 to 280) peaks,
at the same time a Sanyo is doing it's hi-power sprint..
That's when we see the big BTUs, and the short brown-out.. :mad:

But, the unit re-started in a few minutes and is now working fine..

Like I've said before, I don't recommend the Sanyo 24KHS72 because of this problem.

When I was trained to fast-fill SCUBA tanks, I was told to always put the tank
in a big bucket of water, to keep the steel tank from over-heating.
I asked my boss, "is the steel expanding and getting hot"?
He said, nope, it's the atoms inside the tank being forced together so hard.
They are rubbing against each other, producing friction heating.

Since we used large air tanks to fill the SCUBA tanks, with the compressor off,
it's electric motor heat wasn't contributing to the hot air in the SCUBA tank.


I can see how the motor's heating is going to put some BTUhs into the R410A,
but the amount seems too small to account for the difference in pumped BTUs (heat vs cool).

1 watt hour of motor heat equals 3.412 BTUh.

5,000 BTUh of extra heating from the motor heat, means it would be
producing 1.465 kWh in heat losses.. That would blister the paint.. :p