Condenser Question

[dragonhunter]

I just went to my friend's workshop and he has all kind of condensors, from tiny to huge ones. How do I know which one will work with a Vapo LS and able to handle an overclocked Quad 24/7? thanks :confused:

[Xeon th MG Pony]

find a condencer that would be rated for 500 Watts, or even a nice 1Kw condencer (3,100BTU)

[dragonhunter]

find a condencer that would be rated for 500 Watts, or even a nice 1Kw condencer (3,100BTU)



So any 500W and 1KW condensor will work with an LS as long as it fit the case? Is 1HP good? thanks

[dragonhunter]

oh crap!!! I mean the Compressors, thanks

[teyber]

o!
first off, don't listen to all i say, wait for someone to confirm.
well. As long as it fits in the case, if you know what hp it is, great. A 1hp problably will not fit in the case{and i mean by inches(a lot)} so the usual choice is the nf11fx, or nf11f depending on wher eyou live(120v/220v) so i would say that, but a 1/2hp would be nice.

[dragonhunter]

o!
first off, don't listen to all i say, wait for someone to confirm.
well. As long as it fits in the case, if you know what hp it is, great. A 1hp problably will not fit in the case{and i mean by inches(a lot)} so the usual choice is the nf11fx, or nf11f depending on wher eyou live(120v/220v) so i would say that, but a 1/2hp would be nice.

So any 1/2HP Compressors will work with an LS as long as it fits the LS case?
How do you measure the performance output of a Compressor?

[teyber]

its usually in btu's. THere is a conversion somewehre here....

A 1/2 hp would be a beast, seriously though im going to be honest, i do not build phase changes(yet) so before you go but something, let a builder confirm.

[Xeon th MG Pony]

Ok first off, Hp = total utter useles garbage! means nothing!!

Now that we have that clear, we can get onto what really does matter: Boiling temp, since we are using low temp at the evap, we want a LBP compressor, So any compressor that is rated for low boiling temp service that moves 300, 400W @ -30C will work.

[PhilippF]

the usual choice is the nf11fx, or nf11f depending on wher eyou live(120v/220v) .


The Danfoss NL11F is the usual choice for pimping the Vapo here in Europe (230V), along with replacing R134a with R404A. I think, if you stick to a mod many have done before, you couldnt be wrong. Also, the NL11F doesnt use too much power (depends on load and temperature, but under 200W).

EDIT: Also a very reliable compressor, price is about 100 Euros here in Germany.

[[XC] gomeler]

From the Danfoss line the NF11FX or the SC15FX would be superb, from Embraco I've been using the FF12HBX but I'm trying to find a supplier of NEK2134GK or NEK2150GK compressors. Those are all I've been looking for in hermetic compressors, I'm sure there are tons of suitable compressors.As Xeon says, HP is useless, look for what load it'll carry in a given range.

[killermiller]

Can you have a condenser that is too large?

[DetroitAC]

Technically speaking, there is no such thing as too large of a condenser, meaning there is no thermodynamic or heat transfer reason.

Practically speaking, it's a matter of diminishing returns. Say you take a condenser that is "normal" for any given refrigeration system, and put one in that is twice the size and keep airflow the same, you may get 10% better performance, double it again maybe get 2% more, double that and maybe 0.5%. All the while, the condenser has grown to massive proportions, the refrigerant charge is massive, and it's requiring a ridiculously large shroud to distribute the air.

It's an economics problem, you look at the cost and package of a condenser that will get the job done, and you look at the cost and package and performance gain of the next sizes up and make an economics decision.

I don't think it's correct that a compressor's hp is totally useless. It's still a "ballpark" measure of how big the device is. If I tell you I have a 1/12 hp compressor, can I cool a quad core to -40? NO, grow up and get a job DetroitAC! If I tell you I have a 1/2hp can I cool a quad core to -40, well yes you have a shot there...let's look at the specs of that compressor, and do some calculations.

[killermiller]

Do you know how many BTU's "Little Blue" is rated for?

[Xeon th MG Pony]

For sizing the condencer I take the total heat of compression plus total heat rejected and then multiply by 25% If you live in an area where temps can spike very high or it will have high sun loads you may even want to go by 50% to 75%!

Compressors Wattage+Wattage moved by compressor*1.25= Total condensor size.

Detroit, only time you may get away with Hp being of use is in A/C, but when it comes to Low Refrigeration the cc Vs SST and rotation, at this the Hp is not at all usefull but rather its displacement and rotational speed. So I think I'll stand by my insistance that Hp is a totaly utterly useless figure for this, all that matters is the compressors BTU @ Evap temp is usefull second only to the displacement value along with target temp of the evap.

While at this I'll remind every one, refrigeration starts at the evap, not compressor, To properly design a system you must know what temp you want @ what wattage, you then size the compressor from that figure, then you size the condencer! Same with cascades, you start at the evap and work back wards, by doing so you need not hope it will work, it will work!

[killermiller]

Can the wattage moved by the compressor be found on this?

http://img99.imageshack.us/img99/2015/nf11fxspecsrw3.th.jpg (http://img99.imageshack.us/my.php?image=nf11fxspecsrw3.jpg)

[tim-]

yes in the line "power cons. in w"

[[XC] gomeler]

I have this PDF printed out and I refer to it quite often when dealing with Danfoss compressors.
http://de.refrignet.danfoss.com/TechnicalInfo/Literature/Manuals/06/compressors_r134a_lbp-mbp_220-240v_50-60hz_02-2004_cb40i302.pdf

power cons = power consumed, not the amount of heat it is capable of moving. That is also a useful number but capacity is much more important.

[killermiller]

So..... How many watts is Little Blue rated for?

[DetroitAC]

Detroit, only time you may get away with Hp being of use is in A/C, but when it comes to Low Refrigeration the cc Vs SST and rotation, at this the Hp is not at all usefull but rather its displacement and rotational speed. So I think I'll stand by my insistance that Hp is a totaly utterly useless figure for this, all that matters is the compressors BTU @ Evap temp is usefull second only to the displacement value along with target temp of the evap.


Well, that's a bit entertaining for me.
So, if I tell you I have the 1/12 hp compressor and I want to cool 250W @-40...you would look up the specs???

I'd save that 10 minutes of my life for something useful...

[Xeon th MG Pony]

I wouldn't bother copying what ever you claimed to have, I prefer to make things designed for my task, so Hp would still be an irrelivent messure, it isn't an acceptable way to do things in the industry whats more usefull: "I got a 1/2Hp R-507 compressor" Or "I have a R-507 1,865btu/h compressor @ -40f" ??

[n00b 0f l337]

So..... How many watts is Little Blue rated for?
Sorry to see you geting ignored, but I think the answer is, we don't know.

[DetroitAC]

whats more usefull: "I got a 1/2Hp R-507 compressor" Or "I have a R-507 1,865btu/h compressor @ -40f" ??
The latter is more useful, but try asking for a compressor that way at your refrigeration store. I don't think I've said specs are not more useful? My point, maybe we've lost track of it :rolleyes: , is that the hp rating is not "totally useless", it is a figure that tells you the "ballpark size" of the pump. I am "in industry", and I am a professional engineer, and I can tell you that ballpark numbers are used.

Someone comes up to me and they say:
Hey Erik, can I meet Ford WCR spec on the Expedition with a 100cc piston pump?
NO
But don't you want to see the specs on the compressor?, do some calculations? some simulations?
NO, get lost

Hey Erik, can we take the steel out of the Blue Water bridge and replace it with wood?
NO
Don't you want to see the specs? I have some really fine Norway Spruce, don't you want to do some calcuations?
NO, go play in traffic

Hey Erik, can I drop my bad 'ol 3cyl Yugo engine into Viper and jump all over those stinkin' V10s at the line?
NO
Don't you want to see the specs?
Will you be able to fit 8 of them into the Viper? NO, then go bother someone else

Hey Erik, can I use a 1/12hp pump to cool a processor to -50C @300 Watts?
NO
Don't you want to see the specs? It's a Danfoss! and I'll be using a superblend of R507 and R404A!, Don't you want to write a model, do some calcualtions?
NO, go pound sand
How about a 3/4hp?
OK, show me the specs

My point, (besides I'm bored and don't mind arguing a point) is that the hp rating of a compressor has SOME use. I pull out the calculator when I need it. I write an EES math model of a refrigeration cycle when I need one. If there is zero chance that something will work, who cares about the specs? This is the use of hp size. When someone new to phase pops up and tells us the hp size of their compressor, I'm not going to lecture them about how it's meaningless, it means something to me. :D

I hope you don't take offense Xeon, It's still quite entertaining for me.

[Xeon th MG Pony]

On A/C I said you can get away with it as capacity is oft 1 to 1 with Hp, in comercial refrigeration we frown on people using Hp, it is an all to common error, as capacity will not be in direct perportion with Hp.

[killermiller]

Do you know how many BTU's "Little Blue" is rated for?

So..... How many watts is Little Blue rated for?

Since this is still a condenser thread, I am going to ask about one....

Does anyone know the rating for little blue?

Are there any other shops to purchase condensers in the US?

[PhilippF]

So..... How many watts is Little Blue rated for?

It´s a rough guesstimate, but I would thing 350 to 400 Watts. If it is made of special tubing with checkered (right word?) inside, it could be used for up to 500 Watts I think. Shuld be enough for a regular single stage.

EDIT: Btw, this HP-rating of compressors seems to be a USA-only-thing, as nobody in Europe uses it...^^

[Xeon th MG Pony]

It´s a rough guesstimate, but I would thing 350 to 400 Watts. If it is made of special tubing with checkered (right word?) inside, it could be used for up to 500 Watts I think. Shuld be enough for a regular single stage.

The word is gnarled or riffled. depends on the patern, usualy it is just riffled.

I'd say 400W would be boarder line as you must include the compressors heat as well as heat moved, so 400W NET or 400W gross?

To properly make a system you must start at the evap! What temp are you aiming for at what wattage? Then you find a compressor that can handle that wattage at that temp, then you add the wattage moved to the wattage the compressor uses = Condencer*25% for a safety factor.

[PhilippF]

My guess was 400 watts gross.

[killermiller]

Sorry to see you geting ignored, but I think the answer is, we don't know.

Between the discussion, I didn't even see your response. Thank you for your response


It´s a rough guesstimate, but I would thing 350 to 400 Watts. If it is made of special tubing with checkered (right word?) inside, it could be used for up to 500 Watts I think. Shuld be enough for a regular single stage.

EDIT: Btw, this HP-rating of compressors seems to be a USA-only-thing, as nobody in Europe uses it...^^

Thank you.

[Xeon th MG Pony]

Same in Canada most do not use Hp, We for the most part use heat removed by the system.

[DetroitAC]

this HP-rating of compressors seems to be a USA-only-thing, as nobody in Europe uses it...^^

Mostly true, Danfoss builds the displacement of the compressor in cc into the model number. Bitzer however, lists the nominal motor power in kW (exactly like American nominal motor horsepower) and actual displacement (vol. eff. taken into account) as their primary quick sizing parameters.

Thanks for letting me get away with it Xeon! Not sure what "it" is, but I'm gonna run like I stole it!

[Xeon th MG Pony]

LOL Detroit thats funny, Speaking of A/C my assorted nicknacks from ebay arrived and my hands are now flourecent yellow! Quite the score, seems I have a converter for at least two types of make for R-134a and R-12 :)

[tim-]

americans do like to be special :lol: