would this work?

[BradC]

Originally Posted by nexsuperne

The 1 ton ac unit I have is filled with r407c. Can I put r290 in it?

R407C is a blend of three HFC refrigerants designed to give it properties similar to R22. Given it's HFC the oil is likely to be POE.

HC's will work with POE oil, however it is mightily hygroscopic, so you *will* need to install a liquid line drier after you've finished messing with the system.

R290 will have lower pressures overall, so you might need to tweak some stuff.



<edit> Huh, lost the legends
Pressure in PSI, Temperature in C. Orange line is R407C, Blue line is R290

[nexsuperne]

So does this mean that 407c has a higher heat output than 290?

[BradC]

Originally Posted by nexsuperne

So does this mean that 407c has a higher heat output than 290?

Look, there is no easy answer to that question. When compressing different refrigerants using the same relative pressures (and therefore compression ratio), they heat up different amounts. It's all to do with the heat generated as the molecules rub together as the gasses are compressed (and therefore to do with the size and shape of the gas molecules).

I don't have either the knowledge or data to be able to quantify the heat of compression other than to refer to anecdotal evidence scattered around the web. As far as heat of compression goes (and therefore discharge temperature that will favour you when using a heat pump to move/generate heat rather than remove heat) all the evidence points to R22 having the highest, and 410A and 290 seem to follow roughly in about that order.

[Xringer]

IMHO, R410A runs at such high pressures, it isn't really a very good choice for DIYers.
Unless, your hardware was designed to run with R410A.

[AC_Hacker]

Originally Posted by Xringer

...Unless, your hardware was designed to run with R410A.

Not only your hardware, but also your gear.

If you had a manifold gauge set with hoses, that was built for R-22, you would definitely be lowering your factor of safety (to say the least) if you used it (or switched hoses) to work with R410a.

-AC_Hacker

[nexsuperne]

At the moment I am trying the 'quick and dirty' method. There is enough pipe to be able to relocate the condenser hx into a custom made plastic insulated water tank, without spliting the system and trying to obtain some 407c.

[Xringer]

Originally Posted by nexsuperne

At the moment I am trying the 'quick and dirty' method. There is enough pipe to be able to relocate the condenser hx into a custom made plastic insulated water tank, without spliting the system and trying to obtain some 407c.

I've seen people trying to use that method for CPU coolers, but it sure seems messy, and not that easy to do..

My brain storm for going that path was to cut long thin slots,
half way down the side of a large plastic trash bucket.
(The bucket would have two hose taps installed).
Then lower the condenser down inside the bucket, with the refer lines in the slots.
Tape up the slots a bit, cover the top, and wrap the bucket with insulation.
Connect up the hose taps and pump the hot water into storage..

That water might no be too clean, if the AC has been used very much..

The problem with this kind of system, is the pumped water is in an Open Loop.
So, you can't apply much pressure to the input, without over-flowing..
The cure is to limit the amount of water to a few gallons..
Enough to keep the condenser submerged.

I want to connect my ASHP to a 30 PSI boiler, so I'm going to use an HX..
http://ecorenovator.org/forum/geothe...hw-heater.html

[nexsuperne]

Well I have just finished testing my quick and dirty setup. It runs at 48C, which is plenty hot enough for my domestic water. It only pulls 900 watts, and is a 1 ton unit. I have a programmable thermostat, which is set for 2 minutes compressor startup delay with auto shutdown at 0C when the evap hx gets that cold. To maximise the cop, I will set the condenser hx temp to 42C max.
I would like to hack this to put in a refrigerant to water condenser hx,but need flared compression fittings, a suitable hx, a filler valve and some r407c. Is there anyone in the UK that wants to do this for a price?

[nexsuperne]

I have just acquired a 24" x4" x4" heat exchanger it has sweat fittings, which are 1/2" and 3x 3/4". It is rated at 31 bar. Can I use this to replace my condenser hx?

[Xringer]

450 PSI working pressure should be okay for R22 or R290,
but as you can see from the chart above,
R410A pressures are too high for your new HX.

What type of HX is it? And do you have the BTUh rating?
Post some pics or a link, so we can see what you are working with..