Heatcraft Condensing unit for air conditioning?

[Poodle Head Mikey]

It really works great for comfort cooling though. <g>

PHM
------

134a isnt the best option for a freezer .... but they do it

[pecmsg]

134a isnt the best option for a freezer .... but they do it

Carrier uses it in there Trans Cold Systems.

Nothing like a 20" suction reading!

[idontgetit]

To check the claim that R404A is not efficient at higher evaporator temperatures

It’s not a claim.

Even your own data I clipped showed the mass flow rate from 20f to 40f increased from 600 ish to over 1000 lbs.

The difference from 0 to 40 is around 11 times as much mass.

Thank you for doing the research on it.

Any thoughts on why in the nearly 40 years of its use it hasn’t been used in air conditioning applications?

[shellkamp]

It’s not a claim.

Even your own data I clipped showed the mass flow rate from 20f to 40f increased from 600 ish to over 1000 lbs.

The difference from 0 to 40 is around 11 times as much mass.

Thank you for doing the research on it.

Any thoughts on why in the nearly 40 years of its use it hasn’t been used in air conditioning applications?

If it wasn't a claim, what was it?

As far as not being used for air conditioning: My guess would be cost.

Sent from my motorola one 5G UW using Tapatalk

[Poodle Head Mikey]

I'm not positive but I am almost sure that when recently selecting an only slightly larger Trenton condensing unit I remember the HT rating was a max of 50º F. SST

Although as soon as I wrote that I realized that may have been a semi and not a scroll. <g>

Academic - as a 45º SST would be all AC requires. Especially matching the BTU's and using 110º condensing temperature.

PHM
-------

Heatcraft rates all of their medium temperature scroll units up to 40°F evaporator temperature and Copeland rates the ZS scroll compressor up to 45°F evap temp for R404A. I see no problem using them for an R404A air conditioning application.

The Sporlan "C" charge will work fine in the 40-45°F range as its performance is fairly flat over a very wide range from HT, MT and LT.

[Poodle Head Mikey]

So what if the mass flow rate varies even geometrically to the pressure? All that thinking has been done in applications testing. The condensing unit rating in BTU's at the rated SST is all that required to mate the unit with the AC evaporator, isn't it?

And it would be easy to plot the published HP against the published BTU's, wouldn't it?

PHM
---------

Actually this is NOT a good idea. While some very bright minds have suggested it might be workable with a change in TEV ETC sometimes folks forget things.

While many people will often hear me say things like "pressure doesn't matter its the temp" this is actually a time that phrase is wrong.

Compressors move cfm or swept volume and While the return vapor temp has a big affect on it, not as much as the pressure. R404a has a very large variation in its mass flow rate aka pounds pumped across the very low, low, and medium temp ranges.

At the risk of the typical response to any mistakes word, I am not looking it up but it won't be less important. At a 0 degree evap compared to a 40 degree evap your mass flow for the same volume swept is going to be around 10 to 12 times as much. In other words At 0 if you are moving 50 lb per hour at 40 you are going to need to be capable of moving 500 to 600 pounds for that same volume.

A 410a system with fan cycling in combination with a headmaster or an ori / ord and receiver set up will likely handle in a much better manner.

There are actual reasons 404 isn't used in air conditioning since it's mainstream introduction in the 1990s.

[Poodle Head Mikey]

The H is nice to see but I thought the 6 after it was for R-404 - you have an 8 which I think is R-507.

Although I think that the 040 is HP and I think you are liklier to need 5 HP than to need 4 HP - to get 60,000 BTU's. Do you have the capacity curves?

PHM
-------

Thank you for your input, it gives me something to think about for sure. This is getting pretty technical and it's a little hard to wrap my head around everything, but as long as the compressor is designed to pump R404A and is rated to handle a 40° evap, I'm not sure I see the issue. We aren't talking about turning a Freezer condensing unit into a cooler condensing unit here, which I'm guessing is where your concern might stem from (since that's a fairly common thing that people try to do). In my mind, the jump from low temperature refrigeration to medium temp is a much larger jump than it is to go from medium temp to high.

Anyways, the condensing unit finally showed up at our shop and I got a chance to take a quick look at it. It is actually a Trenton, is rated as high temp, and is listed for multiple refrigerants (basically 404a and a bunch of R22 substitutes).

Here is the model number and a link to a .pdf from Trenton. TEZA040H8HT3DB

I don't have the information from the Bryant air handler/evap, but I think it'll be a 4 ton (designed to use Puron).

According to the chart from Trenton's .pdf, at SST of 40° R404A seems to hold it's own pretty well compared to the other choices, with only R448/449 able to beat it ever so slightly.

So it seems at this point, my choices are to either use a R22 TXV and charge it up with R448A, or use a R404A TXV and charge it with R404A. Unless I'm missing something, according to the specs that I've read, it's more or less a wash either way.

I'm still leaning towards filling it with R404A.

[icemeister]

It’s not a claim.

Even your own data I clipped showed the mass flow rate from 20f to 40f increased from 600 ish to over 1000 lbs.

The difference from 0 to 40 is around 11 times as much mass.

The mass flow increase for R404A is irrelevant when the resulting EER (Btu/kw) numbers are as good as those for R410A.

[ammoniadog]

The H is nice to see but I thought the 6 after it was for R-404 - you have an 8 which I think is R-507.

Although I think that the 040 is HP and I think you are liklier to need 5 HP than to need 4 HP - to get 60,000 BTU's. Do you have the capacity curves?

PHM
-------

I was wrong in my first post. I'm not the one who picked out the equipment, and I don't have all of the details yet. I have seen the condensing unit. It has a 4 horsepower compressor and is rated for multiple refrigerants. I have not seen the A-coil yet, but I'm pretty sure it will be a 4 ton.

I've already picked out the expansion valve that I want to use. It's a SSE-4-C, which is a R404A valve made for medium temp. I also picked up a Chatleff adapter and some reducers that I'm assuming that I'll need.

I certainly could throw in a R22 valve and charge it up with a R22 substitute if there were a good reason, but using R404a just seems like a lot more fun.

[idontgetit]

The mass flow increase for R404A is irrelevant when the resulting EER (Btu/kw) numbers are as good as those for R410A.

Not sure I agree with you on that one sir. I haven’t bothered looking at it but I have questions regarding the distribution tubes etc.

You can lower that eer with a gas like 407f, have the same capacity, run about 6 to 7% more efficiently and lower discharge temperatures significantly.

[icemeister]

Not sure I agree with you on that one sir. I haven’t bothered looking at it but I have questions regarding the distribution tubes etc.

You can lower that eer with a gas like 407f, have the same capacity, run about 6 to 7% more efficiently and lower discharge temperatures significantly.

I hadn't really considered the low side. The R410A evap coils can have some pretty small tubing. Good point.

[Pandelerium1138]

Why not a standard condenser with an ICM head pressure control. I have a couple installed in places that need ac in winter and they seem to work well. Even has a bypass to allow heat pump operation of wanted to go that route.


Sent from my iPhone using Tapatalk

ICM head pressure controls are great if you have ball bearing condenser fan motors. They take out sleeve bearing motors, even with the settings up where they recommend.

[Poodle Head Mikey]

There was lots of talk about running out of R-22 and all that stuff at the time: nobody was recycling it, etc.

At some point I don't a damn for efficiency - I just want my house cool when I want it cool and I intend to have what I want. <g>

And an R-22 system will pump R-404 so it was an obvious path to look into. As it turned out that wasn't necessary so that was the end of it. If it comes down to some armageddon grade circumstance I'm willing to pump propane with a 500 RPM open drive compressor and use R-22 controls. <g>

PHM
-------

It’s not a claim.

Even your own data I clipped showed the mass flow rate from 20f to 40f increased from 600 ish to over 1000 lbs.

The difference from 0 to 40 is around 11 times as much mass.

Thank you for doing the research on it.

Any thoughts on why in the nearly 40 years of its use it hasn’t been used in air conditioning applications?

[R600a]

There was lots of talk about running out of R-22 and all that stuff at the time: nobody was recycling it, etc.

At some point I don't a damn for efficiency - I just want my house cool when I want it cool and I intend to have what I want. <g>

And an R-22 system will pump R-404 so it was an obvious path to look into. As it turned out that wasn't necessary so that was the end of it. If it comes down to some armageddon grade circumstance I'm willing to pump propane with a 500 RPM open drive compressor and use R-22 controls. <g>

PHM
-------

That reminds me of a system I've been wanting to build. I want to set up a single cylinder Briggs & Stratton engine running either propane or natural gas depending on what I have available when I get around to it and spinning a Chevy truck AC compressor running my home AC system with 134a refrigerant. I want to do it just for the fun of doing it not because I think there's any real advantage to it although it might be cheap to run on natural gas if if I could get the engine tuned just right and running nice high compression. I was thinking I could even use a serpentine belt system and put a alternator and car battery so that I can power the controls off 12 volts if I wanted to do.

Sent from the Okie state usin Tapatalk
"Is this before or after you fired the parts cannon at it?" - senior tech