Propane (R-290) for heat pumps?

[Xringer]

Yeah, this thread started life being about Propane and Propane Accessories (HXs etc & safety),
but there hasn't been a lot of info posted lately.

So, I posted the link to the 2011 Annex 32 Reports,
if anyone was interested in what they were doing in Norway
with Propane heat pumps these days..

Since it gets pretty cold in Norway, that would kinda indicate
that propane might be as good or better than R410A in ASHP heating applications.

I wonder if there is any evidence of that idea.?.

[Xringer]

Nice little chart for R290


110F @ 204 PSI is pretty nice. Seems like a nice safe pressure compared
to R410A at 110F, which runs about 360 PSI.

[Geo NR Gee]

So, the lower the pressure, the better? Does it mean that the compressor doesn't have to work as hard?

[Xringer]

From what I've heard about people replacing R22 with propane, less power is used.
But lower pressure also means less chance of a copper pipe busting...

[AC_Hacker]

This thread is now 10 pages long and has almost NO POSTS by anyone who is actually working with R-290 and who is speaking from experience.

Not very DIY.

However, I did find a very interesting post, from another site, regarding R-290, written by someone who actually does use R-290.

Not wanting this valuable post to get lost in this thread's flurry of conjecture, I have appended it to the 'manifesto' thread.

Enjoy...

Regards,

-AC_Hacker

[Xringer]

Hey! don't rush me! I'm going to use some R290 one of these days..

I actually have a candidate system. Already converted the Contactor relay. Replaced it with a solid state relay..
I've looked at the two other relays in the system and they are very small
and look tightly sealed. (Not much internal volume).

Right now, I'm testing it with R410A, to make sure everything is tight.

I did see that oldtimer's rant back during the summer. He sounds pretty convinced about the safety of propane.

My main area of interest now, is finding out how well is propane going to work,
in a system that was likely designed to run with R410A.
It would be good to know how a mini-split will work before going to mineral oil and propane..
It would be a pain going back to R410A..


I have heard from one person who claims to have used propane with his R410A system. He said his results were good.

~~~
YouTube - Broadcast Yourself.


I have a 14,000 btu portable air conditioner that had a cracked joint. The crack has been repaired however the system is R-410a. Can I use propane in this system to recharge? Does the capillary tube need to be adjusted? I know it uses POE oil and is compatible with propane but the big question is the pressures using it as a drop in replacement. Never seen this done on a R-410a system. Can it be done? Around here R-410a is sold in 30lb tanks and costs more that the unit is worth.
AlumaFX 1 year ago



@AlumaFX Now that summer is getting closer I wonder if you gave the Propane a try in your AC?

I also have a broken R410A system, and I'm thinking that Propane might be an cheap way to get the system running again.. (After I repair the leak).

Thanks,

Rich

Xringer 8 months ago


@Xringer Yes, I did this last summer. Used it all summer and it worked great! It consumed about 8-9 amps of power to drop the temp from the intake to the output approx 20 deg F. The great part is a new unit of the same model was only able to drop the temp 18 deg F while drawing 13-14 amps. Not only did it save me $ not buying a new one but it also save a ton of electricity. The unit ran day and night keep the entire down stairs nice and cool without any issues. It was also much quieter.
AlumaFX 8 months ago


Sounds pretty good to me..

Cheers,
Rich

[MN Renovator]

I think the big question is whether or not the lower pressures needed for use in an R290 versus a higher pressure R410a(even higher than R22), would be, Do inverter units control their speed under certain levels of pressure? I've run into the details from Youtube showing the more efficient units like Fujitsu's being pulled apart and commentary about far more sensors in places that don't normally have them. I'd imagine in a simpler system this would be easier but if you put a low pressure gas(installing at the pressure it needs to be at) into a system that is expecting a high pressure gas, could we expect a good result?

I wouldn't mind a 20% increase in the efficiency of the inefficient old 1986 R22 single stage builder grade A/C unit outside my house but I'd be more unsure about using it in something that might monitor the pressures a bit more.

Maybe my concern is unjust, I'm not sure. If I had the equipment and could withstand the risk of putting the extra cost into it, I'd try it. ...probably with a cheaper China-sourced one though.

[Xringer]

There are 3 temperature sensors in the ODU.
I think, maybe the one on the output of the compressor might,
be what tells the control program to start stepping down the power..

The indoor unit has a coil temperature sensor, that might also be feeding back some control info.

http://i46.photobucket.com/albums/f1...OutdoorSSR.jpg
http://i46.photobucket.com/albums/f1...indoorunit.jpg

The actual indoor temperature is not a big factor in short term power use, since it's monitored using a 5 minute timer.

Seeing how well the AC mode worked for AlumaFX, and reading a few reports,
this mini-split should work pretty well with propane..
Maybe 30% better than before. I'm just wondering about heating during real cold weather.

[AC_Hacker]

Originally Posted by MN Renovator

...probably with a cheaper China-sourced one though.

I hate to be the one to break this to you, but that is where they all are from now.

-AC_Hacker

[AC_Hacker]

Originally Posted by Xringer

Since it gets pretty cold in Norway, that would kinda indicate that propane might be as good or better than R410A in ASHP heating applications.

I wonder if there is any evidence of that idea.?.

How can anyone find that out?

-AC_Hacker