Basically all I need to know are the pressures you would most likely see from a 407c split system. I need to get a base line for the pressures in both heating and cooling. Has anyone got any ideas?
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Basically all I need to know are the pressures you would most likely see from a 407c split system. I need to get a base line for the pressures in both heating and cooling. Has anyone got any ideas?
Somewhat higher than R22....
http://www.3dair.co.uk/download-files/r407c-guide.pdf
Good detail treatment and deals with splits in particular. See particularly lubricants.
hi xeomus,
R-407c on my comparitor dew 0c= 52 psig
bubble 0c = 68 psig
hope this helps? sedgy,
Why don't you look at your comparitor and see what temperatures you want, then look at the pressure for that temperature.
This system works for all refrigerants.
Gee, that's too easy Frank, takes brain power that does. :DQuote:
Originally Posted by frank
:D Sometimes Brian, it's the obvious that some people can't see..:)
frank and brian,
I dont know if you are aware but a lot of youngsters < mostly in europe< dont even know what a conparitor is, never mined how to use one, as allways I was instigating the progress of the same when < as usual someone came on as usual taking the p< water out of the youngsters who want to know things, they dont want people taking the piss. its a pitty a lot of experiance engineers have not got the man management skils,
or the teaching skils to get the best out of theses youngsters, yours sedgy= ex teacher , coach , and mentor
Hi Sedgy....no intention of taking the P.... out of anyone. That's not my way, and I'm sorry if it sounded that way.
It's just that the question is always asked 'what pressures should I be looking for?'
Our trade is all about Temperature control but for some reason, our younger engineers (or older learners) seem only to want to know about pressures. Maybe it's the way it's taught nowadays in college, I don't know?
sorry frank, I jumped in . again
I think what you are looking for is expected running pressures of a heat pump air conditioning system and not a desired temperature for setting a freezer.
If this is so always evaporating above zero, 4 or 5 deg celcius, R407c will have a low pressure (suction ) of about 50 psi. and a high pressure ( discharge ) of about 280 psi, which is about 55 deg celcius, cooling cycle. Standing pressure ( system not running ) will depend on surrounding temperature of outdoor unit. Cant say exact without refering to gauges or comparator.
Hope this is of use to you. If you are have gauges refer to them, if gauges dont have R407c on them you can get pop on dials to existing gauges, save buying new ones.
NevQuote:
Originally Posted by Xeomus_Aevis
Cheers for the help guys, those of you who werent taking the micky out of me anyway. When your college / business is too cheap to provide a comparitor i sometimes forget they exist.
It is not " taking the micky out of me"! You should be thankful to them, because they are not telling you pressures you expect, but guiding you in right way to do things. They are not giving you fish for one meal, they are guiding you to search for way to learn how to catch fish every time you need a meal..
If you know basics of operation of split type air conditioner then you will know what would be temperature difference between mediums in question in both heat exchangers. These temperature differences (TD) are what is all about.
Pressure of refrigerant depend on saturation evaporation/condensation temperature which is dependent on TD of evaporator/condenser. TD of heat exchanger is dependent on heat exchanger materials, construction, cleanliness and flow of media at exchanger.
Some guiding numbers are:
http://www.refrigeration-engineer.co...2775#post92775
When you know these numbers than you know expected saturation temperatures of evaporation/condensation for your concrete case.
When you know expected temperatures, than you know corresponding refrigerant pressures and what to look for on PT comparator or directly on gauge.
You cannot ask for pressures without providing data about conditions. They could wary widely depending on conditions.
Example:
http://i46.tinypic.com/2zowxaa.jpg
Therefore, knowing of basics of construction of split type air-conditioner will give you universal answer for all refrigerants and you will newer ask again what pressure should you expect. You will be asking what TD should be, and rest is only matter of measuring air/water temperature and according to that determining saturation temperatures and then finding corresponding pressures.
http://www.refrigeration-engineer.co...ight=pressures