Compressor Q's

[SkipperDK]

Hi Guys

I hope you will bear with my stupid Q's. I couldn't find any answers on this by searching.

I have my eyes on the Danfoss NL11F, for a SS unit. I know it's a popular unit, that gives good performance, good economy, and low noise. I plan on charging it with 402a. My goal is a system with a low and stable load-temp. I don't care how low it will go without load. I value economy in form of a low e-bill and low noise. Don't care much about the price of purchase.

I know the above is a good setup, but I would however like to explore additional options as well. Therefor I need some input on this:

1. If not thinking on price, what would be a better compressor. I want power enough to maintain a low temp under load, and still have good economy and low noise.

2. If going with a smaller compressor, like the NL9F or NL7F. What temps/stability can I expect, and is there any real difference in economy and noise

3. If I overcharge a system a bit, how much will that effect the evap-load-temp?

Any input is appreciated.

Thanks

[Nyx]

You cant just overcharged a system and cool an additional load. It is the components use, the type of refrigerant and the way you design the system that will determine what kind of load you can move.
The refrigerant which exits from the 1st evap already absorbed quite an amount of heat and it could not handle very big loads on a second evap well enough.
U might as well go for a dual evap system but that comes with the price of a bigger compressor to move more heat.

The NL11F is good for a decent cpu load. But i doubt it will handle what you want. If u want to move more load try a compressor with more displacement and horsepower like the SC series :D though a little noiser.

[SkipperDK]

Yes, but I heard they are really noisy, and consume lots of watts. Isn't that so?

[jinu117]

I would consider embraco NEk2150.... but not sure how quiet it really is... (if it is to their claim should be as quiet as nl11f) Also, danfoss itself has energy efficient line start NTY... check them out.

[SkipperDK]

Thanks Jinu

Well Danfoss is kind of my neighbor, so it would be practical to use one of their units :-)

[ayrtonsenna]

i would also use the nl11f,very quiet and very reliable unit.

[SkipperDK]

Thanks

What about the overcharging, what efect does it have?

[jinu117]

Increased highside pressure, not so good unloaded temp not that it matters other than to show off :P, more electricity consumed per same amount of cooling, and worst of all, non condensable (liquid refrigerant) slugging back into compressor reducing life span of your compressor.

[piotres]

Use NL11F. Will be nice for sure :)

[SkipperDK]

How much will it effect load temp, if I go with a NL9F or even a NL7F?

[piotres]

I think that will be sth like 3-7*C higher temps with 7 or 9 ccm compressor :)

All depends on way how You tune your unit .

Peter

[SkipperDK]

So basicly not a big difference, but a lot less watts used?

I want it tuned for best load performance.