In this article, I will be teaching you how to make a “Water Chiller”(AKA “Phase Change Cooler”) using refrigerants. First, to begin you must understand how refrigeration works. The refrigerant will follow this cycle:
- A compressor compresses the refrigerant;
- The high-pressure refrigerant goes through the condenser where it becomes a liquid;
- The liquid passes through a capillary tube to reduce the pressure;
- The refrigerant now evaporates in a low-pressure environment;
- Evaporated refrigerant is suctioned into the compressor.
This is a constant looping cycle. The physics behind why these works are as follows:
As you increase the pressure on a gas, its boiling point raises, meaning once the pressure gets high enough, the refrigerant can become liquid at room temperature. Now it’s liquid but it isn’t cold. Since we
have all this pressure that the freon is liquid but it isn’t cold, it will have to evaporate.
The only way for that to happen is to make the pressure low enough so that its boiling point drops. This is done in the capillary tube. It provides so much resistance that the pressure before it can be a few hundred psi, while the other side is only 10-15 psi.
Since the other side of the capillary tube is only 10-15 psi, the refrigerant expands so quickly that it basically pulls the heat away from the evaporation surface at whatever its boiling temperature at that psi is.
Now that you know the physics behind why refrigeration works, let’s get down to construction:
NOTE: In the United States, ANYONE working with refrigerants must be certified by the EPA. Most STATES also now require licensing to work with any refrigerant. If using old compressors, the refrigerant in the system MUST be recovered by an EPA certified technician – this includes r134a systems. Fines for venting refrigerant can range into the $1,000’s.
Here is a list of some of the things you will need during the construction of your Phase Cooler:
- High temperature blow torch
- High temperature solder or brazing rod
- High temperature solder flux
- Wire cutters
- A refrigeration compressor
- A condenser (can be fabricated)
- Capillary tube (copper tube with an inner diameter of less than 3/32″)
- 20-40′ of 1/4″ OD copper tube (used for evaporator and condenser if it needs to be fabricated)
- Shrader access valves (at least 2 possibly 5)
- 1/4″ copper sleeves OR 1-2″ of 3/8″ copper tube
- Refrigerants – R-134A, R290 are common use because they don’t require you to be licensed to get them
- Refrigerant oil: ester oil is bottled with R134A and would be what is used with any R134A compressor, mineral oil is what is used with
- All other refrigerants.
- You will need something to get the refrigerant into the system here are a few options:
- A set of standard refrigeration gauges or automotive set with adapters
- An automotive R134A fill hose with adapter
- Standard fill hose from a self AC test kit
- High-speed fan
- Water tubing of some sort vinyl – silicon, tygon are some typical types
- A water block can be fabricated relatively cheap or purchased online for $15-100
- Insulation for your water block and tubing. Neoprene sheets are typically used on water blocks and standard poly based plumbing insulation
on the tubing is typical. You will also need to insulate your reservoir for the best temperature.
Now we start assembling our system. The first thing we will talk about is the condenser. Aside from your compressor, this is the most vital part of your Phase cooler; if your condenser doesn’t move heat, your refrigerant doesn’t liquify.
What you really want is something that uses a moderate width tubing with a lot of fins. You’re going to probably want about 20′ of the condenser – the larger your condenser and the more Freon you have, the larger heat load it can handle.
You can check around on fridges and stuff, but most don’t use good condensers – just something that’s good enough to let it run for a few minutes at a time. This is because they are designed to remove heat and keep it there, not to run constantly. You will want something out of an air conditioner or similar.
You’re going to want to look for something that has a 3/8″ or 1/4″ OD pipe; 1/4″ works better because it’s easier to keep up head pressure. You can probably find something like this at a refrigeration shop easily enough if you wish to purchase it. You may get a better price if you just get a sheet of condenser, cut it down and bridge the pipes into a cube style condenser.
For anyone who has the skill, time, and materials to make a quality air-cooled condenser, here is how!
- Sheets of copper about .015″ thick
- 20′ of copper tubing
- Moderate temperature silver solder or tin/silver solder
- Pipe bender OR many copper 180 joints
- Saw with a metal blade (table saw recommended).
- Drill or drill press with 1/4″ bit (drill press recommended!)
You need to decide on how big you want your condenser to be and how many passes – I like the size of 6×6. This enables me to get it all inside of 3 passes.
What you need to do is cut your fins to size. Mine will be 6″x2″ so I can get all my fins out of a sheet or two of 24″x24″. Once you have all of your fins cut out, you need to line them all up and mark where your pipes are going to go through. Once all of the holes required are marked,
get your drill ready.
Use a C clamp and clamp all of the pieces of copper together so all the drill holes line up in the end. Now start drilling your holes. Once you have completed about half of them, you will want to stop and move the clamp to the other side to finish.
Now that all your fins are cut and drilled, start pulling the copper tube through the holes. It will be excessively difficult to bend the 20′ of pipe through the holes. If you want to save money on 180-degree joints, you can do the piping in 2′-3′ lengths and connect them. It will be easier than doing one piece of copper but harder than just using all 180’s. Personally, I’d just cut each piece of pipe so that it will be about 5 1/2″ long and connect it on both ends with copper 180 turns.
For those of us who can’t find one for free, do not want to pay for one, don’t have the skills to make a nice one or material to make a nice one, here are a few ways to make a “ghetto condenser”:
Making A Basic Aircooled Condenser
What you can do is crank out about 20′ of your 1/4″ copper tubing and bend it into a maze pattern. The maze pattern will probably give you a bit better surface area contact if you make it a tight maze pattern with about 1 inch between passes 2-3 layers thick. Place a fan on it you will probably get pretty good results.
You again use 20′ of tubing, but this time you coil it up over around the side of one of those blow torch size canisters of propane/mapp/oxygen.
This way you will have about a 3.5″ coil of copper tubing, a perfect size for an 80mm fan – you would want something with a pretty good amount of airflow.
Another thing you can do to increase performance would be to stick this inside a piece of 4″ PVC pipe and attach a 120mm fan to the end of it. This way you will have better airflow with less noise plus it’s all ducted over your condenser coil.
This is probably the most expensive and difficult option, though it will probably yield moderately better results than the previous two mentioned. Start off with the same 20′ of copper tubing. Coil it up as in Method #2. Once this is completed, insert
the coil into the piece of pipe. You will need a pair of “test caps” – they are about 58C or a set of “end caps” which are about 5 dollars each.
End caps are easier to get the proper seal, but test caps are much cheaper. If you really want to seal it, use both. Now drill a 1/4″ hole in the cap and bend a small amount of copper coil out to go through this hole. You will need at least 6″ on each side to ensure that you don’t completely melt the plastic while soldering the pipe.
Once that has been completed, you want to glue the cap in place and run a large bead of silicone sealant around the copper pipe to make sure it doesn’t leak. The next thing you need is a set of hose barbs – 1/2″ or 3/8″ depending on your preference.
Next, you need a heater core radiator – just about any will do (larger IS better). Something like a 1986 Chevy caprice heater core ($35.99 at Auto Zone) should work well. You need to change the fittings on the heater core down to the same size you used on the PVC pipe. Connect that up with some tubing, hook it to a pump and you’re ready to go.
3) EVAPORATOR / RESERVOIR
The next thing to decide on is a reservoir and evaporator. The evaporator should be about 12′ of 1/4″ copper tubing; this should give it enough to get all of the Freon to boil off and give you space to hold a decent amount of extra Freon for heat load purposes. You may want to make it longer depending on your system.
If you are using a weak compressor, you will probably need to make it longer to increase heat load capacity, but this will also raise the final temperature you can acquire slightly. If you have a high power compressor, then you can keep it short because the Freon cycles at a faster rate.
Now that you have chosen how long to make your evaporator, you need to actually make it. Just coil it up and you’re done for now. At this point, your evaporator is made.
Now you need to decide on what kind of reservoir you want.
Many people just rely upon the expedience of Phase Cooling to keep their reservoir cold all the time by having a high flow rate over the evaporative coil. This yields pretty good results for systems optimized for a high flow rate with a GOOD compressor to back it up.
For those of us who like to have a buffer zone, we want a larger reservoir. In addition, if you use a small compressor, the refrigerant doesn’t cycle super fast. With a small compressor, you don’t have a huge heat load capacity so you need to have a larger reservoir, giving the refrigerant more of a chance to cool before it gets recycled.
So in short here are some combos:
- Long evaporator with large reservoir: For people with small compressors and for those of us who would rather have a buffer zone rather than the absolute lowest temperature;
- Long evaporator with small reservoir: For people who have a good compressor but want to use a high flow rate and still have a bit of a buffer;
- Short evaporator with large reservoir: For people with a good compressor but wish to have a buffer zone;
- Short evaporator with small reservoir: For people with a good compressor who desire a high flow rate system with a low buffer for the fastest low temp possible.
As you can see, how you decide to make your evaporator and how large your reservoir is really all depends on your preferences and components.
This is absolutely the most important part of your system – all other parts of your cooler revolve around this part!
The compressor will determine how fast the refrigerant can move, how large the piping you can use, what kind of vacuum you can achieve on your low side. This is the heart and soul of the cooler – if you get cheap here, you’re only making it harder on yourself.
In our systems, the compressor needs to run long cycles, carry a decent heat load, and be reasonable with power consumption. With that in mind, you can use anything from a 1/12hp compressor up, though making it all the way to 1hp is probably overkill. On average, you will not need a compressor larger than 1/4hp and anything 1/6hp or better is above average.
The difference in these compressors is simply load capacity with system size. For example, a 1/4hp compressor with a small system can do an equal load to, say, a 1/12hp with twice as large of a system. This is accomplished by higher refrigerant speeds. With the weaker compressor, it is designed to run a small cycle of probably about 40W of heat, so the refrigerant won’t need to be at its coldest and can cycle at a moderate speed.
In order to get this small compressor, you need to increase the size of the tubing so that you can have more refrigerant in your cooler to compensate for its low flow rate. With a larger compressor, the refrigerant is moving at high speed and the compressor still has room to keep the
low side pressure in a vacuum state, which results in a phenomenally lower boiling point.
What your compressor can do is all determined by your budget and availability of parts. For most of us, cheap is the goal. The way to do that is to try to find something someone is throwing out or at a garage sale. If you happen to see a refrigerator on the side of the road, it may still work or has some silly thing wrong with it.
So it is in our budget’s best interest to knock it over, rip the compressor out and test it. You can get a refrigeration compressor from any number of devices – such as:
- Full size refrigerator: Compressor probably about 1/8 – 1/6hp
- Full size refrigerator freezer combo: Compressor typically 1/6 – 1/3hp
- Chest freezer: Compressor typically 1/4 – 1/2hp
- Full size freezer: Compressor typically 1/5 – 1/3hp
- Mini fridge: Compressor range 1/20 – 1/8hp
- Mini freezer: Compressor range 1/10 – 1-6hp
- Dehumidifier: Compressor range from 1/8 – 1/4hp
- Window AC unit: Compressor range 1/6 – 3/4 hp
As you can plainly see, they are commonly used. For those of us who don’t have a job yet or just don’t have a lot of spare cash, finding one of these at a garage sale for $10 or on the side of the road can make or break the project. For those of us with a big wallet, you can purchase a compressor part.
A compressor starting at about 1/12hp typically can’t be found for under $75; for a compressor with a rating of 1/4hp, you are looking at closer to $175 dollars. The biggest confusion is that a compressor is made for one particular refrigerant and CAN NOT be used for anything else – This is a myth! It can be adapted with a bit of care and effort.
Something you will need to do is find out what refrigerant the compressor was filled with originally – this information leads us to know what oil it contained. This is very important!
If the compressor was charged with anything other than R134a the first time, then it’s 99% accurate to assume that it contained mineral oil. This is not a huge deal. However, if your compressor was originally filled with R134a, this can be a problem as it contains ester oil.
The reason this is a problem is that if you wish to use any other freon to charge your system other than R134a, it will need to be cleaned thoroughly to get all traces of oil out. If you were planning on using R290 or any other refrigerant that doesn’t come bottled with oil, it doesn’t matter what’s in the compressor.
If your compressor was R12, used mineral oil and you want to move to R134a, that is OK because you can purchase R134a that doesn’t contain oil for the purpose of replacing R12/R22 systems. Since the compressor is the absolute most important part of your chiller, I suggest you make sure that you have this first. Make sure it runs and has sufficient power for what you wish to do with it, as a small compressor requires taking further steps to ensure it can handle the heat load.
5) FINAL ASSEMBLY
By now, you should have all of your components selected and purchased/fabricated. Now you need to connect it all up.
Starting with the compressor, connect the shrader access valves if you haven’t already attached these to your evaporator and condenser. Simply “T” joint one onto each of the existing lines. Next, connect the condenser to the high-side line.
Set your compressor down so that the factory fill valve will be on one side with another line going out. The factory fill is either a valve built into the side of the compressor OR an additional copper line that is crimped shut. The line that is closest to the factory fill is the high side line – attach your condenser here.
Next is the capillary tube. If you haven’t already connected this, hook it into any strainer/dryers you have selected and attach it to the end of your condenser. If you have decided to forego the use of either of these, you will slide it about 1/2″ back into the condenser tube and use your wire cutters to crimp down the pipe around it, so that it fits snugly. Solder/braze this shut.
The evaporator is the next thing that must be connected. You need to connect it to the capillary tube the same way outlined above. Take your evaporator and connect it up to your suction line – it should be the line coming out of the compressor opposite the high sideline.
Some of us take the extra precaution of wrapping a bit of this around the high sideline or the compressor to make sure all the freon boils off, but it isn’t necessary. If your charge is right, you shouldn’t have any extra liquid Freon making it into the compressor, but it’s your choice whether to do this or not.
Viola! You now have a completely assembled Phase change cooler. All you need to do is select a refrigerant and charge it. You can have this done for varying prices, depending on your area and who is willing to do it. Personally, I charge my own systems. At the end of this article, I will be providing both professional and “ghetto” methods to do this.
There are many refrigerants in existence which we can obtain, some of which require us to be certified in refrigeration. I will make a brief mention of these but will mainly focus on those which can be acquired by anyone.
Class 1 refrigerant
These are what I consider a Class 1 refrigerant. By this, I mean they were manufactured for the purpose of being used as a refrigerant and will require a certification to acquire. These require no additives to compress properly, have a long life span, and are for the most part non-combustible, BUT they do release chemicals that are dangerous to the ozone layer.
Here is a list in order of common use.
- R12 (dichlorodifluoromethane) was the standard in refrigeration for a long time. With a boiling point of slightly under -21C, it was used widely in automobiles, refrigerators, window air conditioners – just about everything.
- R22 (chlorodifluoromethane) is the refrigerant that has held the standard for home air conditioning longer than any other and is still in use. Its boiling point is just under -40C.
These refrigerants have been in use for years and have been proven time and again reliable and efficient; their only downside is they deplete the ozone layer and thus require a special certification. As a result, they are typically only available in 30lb or larger canisters. These refrigerants come pre-bottled with mineral oil, so your compressor will need to be adjusted accordingly.
Class 2 refrigerants
Class 2 refrigerants are refrigerants that are commonplace and easy to acquire. These do not require special certification nor do they damage the ozone layer.
- R134A(,1,1,2-tetrafluoroethane) has a boiling point of only -26C; it is becoming the new standard in refrigerators, automobiles, and all other common uses.
- R290 (propane) is also beginning to make its way in as a mainstream refrigerant. With a boiling point of -42C, it is more of a class 4 refrigerant, but because of its new found common use I have included it in my class 2 list. This is randomly used in things such as freezers – a lot of hobbyists use it for home built systems.
These refrigerants are quite affordable; also to be noted is that they come bottled alone or with ester oil, require no certification, and do not damage the atmosphere. As a result of these factors, they are readily available to the public.
Class 3 refrigerants
Class 3 refrigerants are those which have a lower boiling point than standard refrigerants. Often they are hybrid mixtures of class 1, 2, and 4 refrigerants.
- R404B (pentafluoroethane/1,1,1-trifluoroethane/1,1,2-tetrafluoroethane: 44:52:4%) This is one refrigerant often sought after by overclockers. With a boiling point of approximately -44C and available in 12oz cans, this can be a nice choice provided you have your certification.
- R409A (chlorodifluoromethane/2-chloro-1,1,1,2-tetrafluoroethane/1-chloro-1,1-difluoroethane: 60:25:10%) This refrigerant has a boiling temperature of -47.8C; you have to purchase 30lb cans.
- R508B (trifluoromethane/hexafluoroethane: 46:54%) This is one of the best readily available high end refrigerants there is. With a boiling point near -50C, you are lucky to acquire this.
- R-14 (1,2-dichloro-1,1,2,2-tetrafluoroethane) Ranking in with a boiling temperature approaching that of -150C at 1 bar pressure, this refrigerant can deep freeze you faster than you can say lickity split. Provided you are running either a cascade cooler or are have a compressor that can withstand approximately 350psi, it’s a pleasure to work with.
These refrigerants have a moderate – substantially lower boiling point than normal refrigerants. Some can be acquired in small amounts, others have to be purchased in 30lb cylinders.
The biggest issue with refrigerants like R14 is that with its so low boiling point, it requires a lot of pressure to compress to liquid. With this in mind, it may be better to juice up a system that is running on a lower grade refrigerant by adding 10-25% more.
Class 4 refrigerants
Class 4 refrigerants are natural gases. These can be acquired from just about any chemical supply place – some can be located in your own home. These generally have an extremely low boiling point and are difficult to compress due to their weight, but can easily be used as an additive to an existing system to squeeze it for a few extra degrees. These, as you may have guessed, do not come packed with any kind of oil additive and therefore can be used in any system.
- R50 (methane) This a moderately light gas with a boiling point of -162C; it’s the base compound for most of today’s refrigerants. In its pure form, it is a bit too light (molecular weight 16) to work with outside of a cascade cooler. Though this can be used in a system of its own, you will need pressures nearing the 450 marks on a warm day to liquify. Overall a great additive or for use in a cascade cooler.
- R170 (ethane) This gas has a boiling point of -88C and a molecular weight of 30. It’s a much more suitable stand-alone refrigerant than R50. There are a few commonplace refrigerants that are based on this gas.
- R744A (nitrous oxide) This is a pretty commonplace gas these days; with a molecular weight of 45 and boiling point of -89C, this definitely yields some potential, not only as a stand-alone refrigerant but also as a cascade refrigerant.
- R717 (ammonia) This is used in many commercial refrigeration systems. Although it has a rather low molecular weight (just under 18), its boiling point of -33C makes it rather easy to work with. The most widely occurring problem with this gas is its smell and, as it is slightly corrosive, extra precautions must be taken.
- R740 (argon) Coming in with a weight of approximately 40 and a boiling point of -182C, it is easily compressed and, used in conjunction with 25% R134, has a weight that is easily used in a standard air condensed system to maintain a boiling temperature below that of -120C with less than 300 psi. This has a lot of common potentials.
- R764 (sulfur dioxide) This gas has the scores – all around the molecular weight of 60 and boiling temperature of -76C, although it has toxicity issues. Given a bit of precaution not to let a lot of this loose into the air, it will easily yield quite impressive results.
These gasses have quite low boiling points, which would make them all great candidates for a cascade cooler. For those of you who don’t know, a cascade cooler is simply a Phase change system that uses another Phase cooler to cool its condenser, so you can use a very low temperature refrigerant at a decent psi rating.
Each of these gasses has some sort of hazard rating, but then again all refrigerants do. You will need to acquire these liquids compressed or change them yourself if it is going to be the only refrigerant in your system. If not, adding them in at the normal gas phase is a viable option.
As mentioned before, there are a few ways you can do this using various setups and equipment I’m going to start with the “Nanny Boy Way” way and work my way down to the “Ghetto” way.
Nanny Boy Way:
This is basically just hook up your system, take it to a refrigeration shop and have them charge it up for you – costs can range from $15-40.
For this you will need a few pieces of hardware:
- A set of R-12/R-22/R134 standard gauges OR a set of automotive R134 gauges with a retrofit kit
- 1 vacuum pump, any size (can be fabricated)
- Bucket of warm soapy water
The first thing you will need to do is connect your gauges – yellow to the refrigerant, blue to the low side (evaporator), red to the high side (condenser).
What we are going to do now is fill the system with nitrogen to check for leaks, because you don’t want to be wasting potentially hazardous or expensive refrigerant. Connect your bottle of nitrogen to your refrigerant line, open the low side valve on your gauge set and allow nitrogen to enter the system until it gets to about 250psi, then close the valve.
This is where the warm soapy water comes into play. Use a rag or something similar to drip some over every joint and watch for bubbles as the system is cycling. At this point, if you have leaks, you need to fix them. First, let’s get the refrigerant back into its bottle. Open the high side valve on your gauge as the system is running – this will get most of the nitrogen back into its bottle.
Of course, there will be some left. Just close the valves, unscrew your nitrogen bottle, and on to the next step. Nest we need to do is vacuum the system out. If you go all the way down to 29.74 inches of vacuum, all of the moisture should be out of the system. While that’s optimal if you pull it that low you can also compromise the oils.
At a minimum, with a good vacuum pump, you need to run at least an hour. You do this by hooking the suction side of your pump up to the refrigerant hose (yellow) on your gauge set. Click on your vacuum pump and open both the high and low side valves at the gauge. Let it run to your desired vacuum level, then detach it from your system. You are now vacuumed.
The next step is to fill. Hook up your refrigerant bottle to the yellow line and open your low side valve – this will add refrigerant. OK – watch your psi on the high side wait for it to get to about 150 psi, then close the valve. At this point, the low side pressure should be a bit high – 30-40 psi, maybe less depending on your system.
Wait about 5 minutes for this pressure to stabilize and check to see if the evaporator is cold – it will at this point with most refrigerants. By this point, hopefully, your low side is low again (as close to 0 or under as possible). What we can do now is tweak the charge.
If you want a higher heat load at the cost of a bit of coolant temperature, then you want to add more refrigerant to get it so the low side is as high as you can stand (under 50 psi) while the high side is reasonable (220-250 psi).
If you added too much refrigerant or just want more of a vacuum at any cost, let some refrigerant out. To do this, open the high side valve – it will force some refrigerant back into the storage container due to its higher pressure. This will bring down your low side pressure, reducing the coolant’s boiling temperature.
In the above description, you CAN forgo the step of nitrogen testing for a semi-professional job – it will work just fine. You can also forgo the use of the vacuum pump, BUT that is in no way the recommendation of the writer, although your system will function without it.
For the following steps, you will need various combinations of equipment to charge up your system. The steps of nitrogen testing and vacuuming in the above listed method are recommended throughout all of these methods, though for everyone it’s not necessarily possible and can be forgone if absolutely necessary.
You need the following hardware:
- R134 self-charge hose (11.95 dollars at Amazon or similar)
- 1 set of R12 to R134 auto retrofit adapters
- 1 can of R134 or refrigerant of your choice
Take your main adapter and put it on the low side shrader valve and, if using refrigerant other than R134, another to its access valve, and connect it to the other end of the hose (about 1 foot long, so choose wisely). Turn on your system and open the refrigerant valve, allowing refrigerant to flow into the system until the evaporator begins to get cold then stop the flow.
Let it cycle for a few minutes and add a bit of refrigerant. The temperature at the evaporator should get even colder due to a better flow of liquid freon. Watch the temperatures until you get the highest temperature you are willing to stand for and disconnect.
Hook it up to your system and, if your heat load capacity is good and you want to try to bring down the temperature a bit, use a pen or something similar to press in the high side valve to let some out, or hook your assembly up to the high side and open it. Freon should flow back into the container. VIOLA! you’re done!
You need the following parts for this setup:
- 2 home air conditioning self-test set or 1 test set and 1 charge boost set
- The refrigerant that fits the home refrigeration standard (not automotive R134 unless you feel like adapting it)
Take one hose, hook it up to your low side and attach your refrigerant bottle here. Take the little gauge provided with this kit and hook it up to the high side pressure. This isn’t going to provide too much help, but just a bit. Flow in refrigerant using the same instructions provided in the last two methods until the little gauge tops off.
Then let it cycle, detach it from the high side and hook it up to your low side to test your LSP (low side pressure). You want this as low as possible but with still enough freon to handle the heat load, so
20ish is OK and 30ish is good.
For heat load, it will give up a bit of the low temp though if your system was vacuumed, it may read 0psi, which means it’s 0 or in a vacuum, which can be great for temps if your system is big enough. You may want to add or remove refrigerant at this point till you get it to a charge you like.
Method #3 (Ghetto Greatness):
You need quite a bit of hardware for this but it’s a good end-user solution:
- 2 standard compressed air gauges, preferably ones with a vacuum rating
- 4 short steel or brass fittings to attach the gauges
- Flux coated brazing rods (if using other than brass fittings)
- Any of the before mentioned connecting hardware (you can actually purchase a set of hoses for a gauge set without the gauges it’s about $30)
- Refrigerant (DUH!)
Install this stuff before you close your loop or cut your system open and attach this stuff. On either side of the shrader valves, attach your gauge using the fitting and braze/solder it onto the standard piece of copper tubing you’re using – simple stuff. To connect, just slide the copper pipe inside the gauge fitting and if you want, crimp it shut.
Then fill the excess with solder or brazing compound – do this on both sides – and your permanently attached set of gauges. Fill the system, watching your pressures go up until they hit your optimum goal, following the Pro method.
Any of these will work and will be reasonably easy/accurate to perform. For your typical user, pick the method that suits you best. As previously mentioned, you will get better results if you vacuum and use a drier, but they can be skipped if your situation demands it.
Before I go, here are a few common mods that can be done to get you a vacuum pump and refrigerant bottle to fill your refrigeration system:
To fabricate your vacuum pump you need two things:
- A spare compressor
- 1 shrader valve
Wire up your spare compressor, find your suction sideline, and solder/braze-on your shrader valve, making sure your high sideline is open and not clogged. Simple – you’re done. Now have a vacuum pump!
You will need the following:
- BBQ bottle
- 1 1/4″ stem shrader valve
- 1 BBQ extension hose (one that has the threaded end)
- 1 1/4-3/8″ steel hose clamp (screw-down type)
- 1 screwdriver
- 1 pair of scissors or wire cutter
Now bust out your BBQ extension hose and cut it off at the end furthest away from the part that screws into the tank. Shove your shrader valve down inside of this hose. If it’s too small, you can use a pair of needle-nose pliers and your brazing torch to expand it.
Just take the pliers, push them in so they stretch the rubber, and get it in front of a low flame – but not in it. It will heat the rubber so you can stretch it. Once expanded, shove the valve in.
Take your hose clamp and slide it down to where the hose is over the valve stem. Tighten it down as much as possible. Now you have a 50lb bottle of R290 and it cost you about $15 to mod and $9 to fill – that’s a lot of systems to be filled!
So in closing, I’d like to say that I hope that this has helped you learn more about Phase Cooling and how to correctly build one yourself. As you can see, it’s not that difficult given a bit of forethought.
Feel free to email me any comments or additional questions about what is written here. I hope you found this not only informative but an enjoyable read.