Propane (R-290) for heat pumps?

[Xringer]

Propane (R-290) for heat pumps? It seems to work!

YouTube - diy hvac recharge with propane

Anyhow, one of the comments on YouTube was from AlumaFX
asking about using Propane to re-fill a 14,000 btu R410A air conditioner..

I've been in contact with Aluma and he did the Mod!
It's the first DIY R410A conversion to R290 that I've been able to find..

In a PM, he told me, he used R290 all summer with great results.
8-9 amps got a 20F drop (from input to output) verses 13-14 amps
for an 18F drop using the old R410A.

He saved money on his electric bill, and it ran quieter..

It sounds like his system was designed for Propane!

Anyways, I'm really starting to think about repairing the leak in my
spare 24,000 BTU Sanyo, buying a new Sanyo indoor unit ($500), a new line-set etc,
and loading it up with deadly Propane gas!

[RobertSmalls]

Yes, propane is a viable working fluid and a suitable replacement for some refrigerants, but.

As you know, the biggest problem with propane is that it's flammable. A cracked evaporator would create a nice fuel/air mix in your car, house, computer, or wherever. Suitable for use indoors? Your call, I guess.

He reports delta-T and power consumption, but what about mass flow rate times specific heat times delta-T? I have a very hard time believing that changing the working fluid (to one the system wasn't designed for, even) would bring about a 60% improvement in efficiency.

[Ryland]

Your system has a leak? most systems have leaks at some point in their life and that is why the non propane refridgerent is used, not that it doesn't work but the idea freaks people out.

[Xringer]

Originally Posted by RobertSmalls

Yes, propane is a viable working fluid and a suitable replacement for some refrigerants, but.

As you know, the biggest problem with propane is that it's flammable. A cracked evaporator would create a nice fuel/air mix in your car, house, computer, or wherever. Suitable for use indoors? Your call, I guess.

He reports delta-T and power consumption, but what about mass flow rate times specific heat times delta-T? I have a very hard time believing that changing the working fluid (to one the system wasn't designed for, even) would bring about a 60% improvement in efficiency.

A lot of people have gas pipes bringing an unlimited supply of gas into their homes.. Scary!
I think the charge would be about two pounds, I'm not sure, but I think two pounds would fill a basement (think FAE)
and lift most houses up about 15 to 30 feet.

I've heard there is a lot of R290 being used in AC systems,
all around the world these days and it's not causing very many problems.
The nice thing about propane (but not real R290) is the stink smell they add.
You can find leaks quick and easy with your nose..



I have seen glowing reports of higher efficiency. Here's one.
Experimental Investigation OPTIMUM Charge R290



Maybe, if AlumaFX's AC was originally designed for R22, and had been updated to R410A, (to make it legal to sell),
Prehaps R290 is so similar to R22, the AC could have really had a 60% improvement..?.


~~~

Here's a pretty good price on an indoor unit. Add on another 100-200 bucks for line-set and power stuff.. Maybe!

KHS2472 - Sanyo KHS2472 - 24,200 BTU Ductless Mini-Split Wall-Mounted Heat Pump & Air Conditioner (Indoor Unit)

[Xringer]

Originally Posted by Ryland

Your system has a leak? most systems have leaks at some point in their life and that is why the non propane refridgerent is used, not that it doesn't work but the idea freaks people out.

My system had a leak in the outdoor unit. It was replaced by Sanyo.
I still have the old unit sitting in my garage.

My guess is, because of the simplicity of the indoor unit, the likelihood
of a leak indoors is much, much lower than a leak in the outdoor unit..



The fittings are outside..


The outdoor unit is subjected to the most stresses.




But, I think using a gas tight contactor relay might be a good mod..

[Xringer]

Then along came a digger..



Then the house was no more..


I didn't read the story, but in about 96% of these house explosions,
a crew dug into a gas pipe. The leaking gas follows the water pipes etc
into the basements of nearby homes.

The first sign of trouble is a bunch of union guys running away from the area,
followed within a few minutes, by a loud blast..

Yes, gas can be dangerous if handled by really stupid people..

Photos: Hyde Park House Explosion « CBS Boston

[Xringer]

What kind of hose does my propane BBQ grill use?
It looks like rubber hose that I use on my nail-gun.. Does it have a steel mesh inside?

I'm wondering if this type of propane hose could be used between AC heat exchangers?
Are they made to take the temperature extremes?

[AC_Hacker]

Originally Posted by Xringer

I'm wondering if this type of propane hose could be used between AC heat exchangers? Are they made to take the temperature extremes?

Why not copper, a proven material?

-AC_Hacker

[Xringer]

I was thinking of the Direct-Exchange GSHP application, with long runs out to the
the buried exchanger. The price of copper was high the last time I purchased some.
But, copper should be the best bet for 'temperature extremes'..



Just saw this manual, didn't know if it would be useful to anyone or not..
www.nyc.gov/html/ddc/downloads/pdf/geotherm.pdf

[Geo NR Gee]

My question of using the R290 in place of R22 is the additive causing any issues. Specifically Ethyl Mercaptan, an odorant, which is added to propane just after its manufacture as a warning agent. This sulfur compound gives the gas the rotten egg, skunk oil odor.

Would there be any issues with this sulfur compound?