The Homemade Heat Pump Manifesto - Page 20

AC_Hacker · 11-09-09, 08:01 PM

Installing a 'Piercing Valve'

To allow the capture and storage of the refrigerant. I have used a re usable piercing valve before, but I wasn't able to find it, so I went down to the neighborhood refrigeration supply shop and picked up the only one they had which was a braze-on model.

This valve has a removable core, with a tiny plastic gasket, and a brass screw-on cap. The core must be removed, then the piercing valve body is brazed into place on the still-pressurized refrigerant line, then the core is inserted and the cap is screwed down tight, driving the point of the core through the refrigerant tubing.

(* * * The core is removed before installation, because the heat of brazing will destroy it. * * *)

Notice that I cleaned up the tube where the piercing valve will go, this makes brazing much easier. The coreless piercing valve is placed over the tube and a pair of pliers is used to snug the tabs around the tube.

I put some flexible fireproof kiln material that I bought for this purpose, around the area where I will be brazing, to protect everything from the intense heat.

Since my last very positive experiences with 5% Silver-Phosphorous brazing rod, I have been using it exclusively, with no flux, with very good results.

Once the copper was glowing cherry red, I touched the brazing rod to it and it flowed around pretty well. I needed to do a wee bit of touch-up at the bottom, but it went much easier than I thought it would.

So I waited several minutes, until I could comfortably hold on to the newly brazed piercing valve.

Before I put in the core, I pulled a vacuum with a micron gauge attached, and quickly hit 330 microns, so I took that to be 'no leak'.

Next, I removed the vacuum hose, and inserted the core with its tiny plastic gasket. Then I put the brass screw-on cap in and cranked it down with two small wrenches of appropriate sizes. This is the point when the core actually pierces the refrigerant line. There was no hiss or leak sound, or any sign of refrigerant oil to be seen.

However, I did put a little spit over the end of the valve, and sure enough, it formed a bubble... slowly, but a bubble. I also noticed that the valve was becoming suspiciously cold, so there was a very small, slow leak happening...

I suspect that if I put a small neoprene 'O-ring' inside the brass cap, and use assembly lube on the O-ring and also on the threads, I could probably stop the leak, but it was not a confidence builder.

But it still give me a way to hook up my extraction equipment to the AC unit and extract the refrigerant, which was the whole point.

So, I screwed the brass the cap on, and set about, getting my refrigerant extractor equipment ready...

(* * * to be continued * * *)

Regards,

-AC_Hacker

%%%%%%%

AC_Hacker · 11-10-09, 01:20 PM

Please note that I have re-edited the previous post by including several detailed photos and an expanded explanation of the procedure.

More expanded steps in the extraction process are to follow...

-AC_Hacker

%%%%%%%

Xringer · 11-11-09, 05:36 PM

That's a pretty neat way to install a Schrader valve on a piece of tubing.

The first valve idea that popped into my mind, was one of those 'Piercing Valve'
clamp-on things for adding a water supply to an ice maker.

My guess is it might work up to around 200 PSI.. With water anyways.

AC_Hacker · 11-11-09, 05:42 PM

When we extract the refrigerant, we can't just let it drift off into space. In addition to being unlawful in many parts of the world, it is immoral in all parts of the world, as commercial non-organic refrigerants will cause global warming and/or destroy the ozone layer. This has adverse impact on all life, no matter what country you live in.

So we need to make an 'extraction tank' to store our refrigerant in, temporarily or longer. This will allow us to reuse the refrigerant later, or we can take it to be properly recycled.

Small AC units and de-humidifiers hold about a pound of refrigerant, which will fit handily inside an empty propane torch bottle.

So what I did was convert a propane torch, the kind that screws onto a propane bottle, into a refrigerant extraction adapter.

A few simple mods are in order:

To enable refrigerant to go into the empty propane bottle, we need to remove the tiny ball that is in the stem at the bottom of the torch.

I just unscrewed the stem and removed the ball, then put the stem back on, minus the ball.

Next we need to remove the too-small orifice from the torch...

The orifice is a small hole at the end of the torch tube. It is so small you might not be able to even see it. As I recall, I got some pliers and just unscrewed the orifice brass part and threw it away. (It could also be drilled out)

Then I temporarily removed the needle valve from the torch because the heat of brazing will destroy any rubber sealing parts, and then I brazed on a 1/4 inch Schrader valve (Also removing the Schrader core before brazing).

I didn't put the Schrader core back into the valve, because with the needle valve of the torch, there's not much need.

The Schrader valves are used in the HVAC trade and come in various sizes, with 1/4 inch being referred to as "standard". They are really a bike or car inner-tube valve core fitted onto a flare fitting, and usually soldered or brazed onto a copper tube. They aren't too expensive, and it's not a bad idea to get several, you'll probably use them all.

The propane bottle that we will use for our storage tank needs to be really empty of propane. If you shake it and can hear or feel any propane at all, there's too much propane. You should be able to put a known good, un-modified torch on the bottle, and attempt to ignite the torch in the normal manner, and be unable to light the torch because there is not enough propane. But, even after that, there is still propane in the bottle...

So only after the 'fails-to-ignite' test, we put our newly-created adapter onto that bottle, attach a vacuum hose to it, and turn on our vacuum pump, making sure that the needle valve is open, so the last remaining propane can be evacuated... let the vacuum pump run and watch the vacuum gauge go down to full vacuum, then let it run for an additional 10 or 20 minutes minimum.

Voilà!!, we now have a small, cheap extraction tank ready for service.

The beauty of using propane bottles is that each one has it's own ball-valve built into the bottle to prevent gas from escaping. When you remove the torch from the bottle, you can hear the ball-valve snap into place.

Make sure that when you recover your refrigerant, you don't over-fill the bottle. You want to leave a minimum of 1/2 to 1/3 empty. Refrigerant in the vapor state is compressible, but refrigerant in the liquid state is not. If a too-full bottle of refrigerant was allowed to get hot, there is a distinct danger that the refrigerant could expand and rupture the bottle, with unpredictible consequences... none of them pleasant. Stay on the too-safe side.

Regards,

-AC_HAcker

(* * * more to follow * * *)

AC_Hacker · 11-11-09, 05:54 PM

Quote:

Originally Posted by Xringer

That's a pretty neat way to install a Schrader valve on a piece of tubing.

The first valve idea that popped into my mind, was one of those 'Piercing Valve' clamp-on things for adding a water supply to an ice maker.

My guess is it might work up to around 200 PSI.. With water anyways.

Not a bad idea, but the fittings must be brazed.

The little metal ring thingies that are supposed to compress around tubes will not hold refrigerant. If a leak starts, extreme cold suddenly happens, and the tubing will shrink away from the ring thingie and more refrigerant will leak, and more cold, and more leak, etc. I proved it to myself the hard way... It was not one of my better moments.

The re-usable piercing valves from the refrig store (my shop was temporarily out) are almost the same thing, and pretty cheap $5 or so, and have standard 1/4 flare fitting ready to go. They also include adapters to allow good fit on several diameters of tubing.

-AC_Hacker

Xringer · 11-11-09, 06:29 PM

I can see how cryogenic temperatures could be a problem with rubber.
I wonder if some other material might work better.?.
(I've seen rubber balls fail to bounce.. They break like clay when too cold).

Those "re-usable piercing valves" sound like the way to go..

After seeing your work above, I wonder how all that heat effects the
refrigerant and the pressure inside the lines??

I know to keep my CO2 tanks cool..

AC_Hacker · 11-11-09, 06:49 PM

Quote:

Originally Posted by Xringer

After seeing your work above, I wonder how all that heat effects the
refrigerant and the pressure inside the lines??

I know to keep my CO2 tanks cool..

That's a well-considered concern.

That's why the flexible heat stop material. It worked well at shielding parts from the heat.

Only about three inches of line saw any serious heat.

-AC_Hacker

Xringer · 11-17-09, 06:08 PM

I just watched a couple of DIY videos. Some of the stuff shown and talked about sure sounded familiar..

How to fix your home's window air conditioner | Appliances Video « Wonder How To

How to make homemade Redneck freon reclaimer | Appliances Video « Wonder How To

There's a lot interesting stuff on the web these days..

AC_Hacker · 11-18-09, 02:00 AM

This section will cover the extraction and storage process.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>

This blog thread is aimed at an international audience. Some aspects of vapor-compression servicing and modification are regulated in certain geographical areas. Other geographical areas are quite free in this respect. The reader of this blog is advised to find out what regulations may apply, if any, and act accordingly.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>>

As previously stated, When we extract the refrigerant, we can't just let it drift off into space. In addition to being unlawful in many parts of the world, it is immoral in all parts of the world, as commercial non-organic refrigerants will cause global warming and/or destroy the ozone layer. This has adverse impact on all life, no matter what country you live in.

A refrigerant extractor should be used to capture and store the refrigerant. Such a device may be purchased new, purchased used, rented, borrowed or made by the reader.

Xringer shared this video link for those who may want to make their own.

These links may also be of interest to DIY recovery machine builders:

Relentless haunting of pawn shops and ebay may turn up a reasonably priced unit.

Luckily, Bruce-the-Pirate loaned me a recovery machine from his truly impressive store of tools.

The top photo shows the Microvac unit. In the upper right hand part of that picture is the grey filter that the input vacuum hose connects to. On the opposite side of the top is a fitting to which the outlet vacuum hose attaches to.

The bottom photo shows the vacuum hose connecting to the previously brazed Schrader valve on the AC unit.

The other end of the hose attaches to the previously evacuated storage bottle in the photo below. Notice that the bottle is in the deep freeze to help reduce the volume of the vapor inside the bottle. I have used bowls of ice water for the same purpose, it worked just fine.

The next photo shows the valve knobs on the Microvac.

Basically, they are both turned to the "Self Evac" position and the unit is run until a full vacuum is pulled, as shown in the top photo below.

Then the valve knobs are turned to the "Evacuation" position, and the needle valve on our storage bottle is opened. You will see deflection of the gauges as the refrigerant is pumped from the AC unit, through the Microvac, and into the storage bottle, as shown in the lower photo. The unit is run until the gauges indicate that all the refrigerant has been removed from the AC unit.

Then the needle valve on the storage bottle is closed and the Microvac valve knobs are returned to the "Self Evac" position and allowed to run until a full vacuum is again reached.

At this point, the microvac is turned off, the hoses are removed from the AC unit, the Microvac and the storage bottle.

Then the adapter we made previously is unscrewed. You will hear a 'snap' as the ball valve in the bottle snaps into position, sealing the bottle of refrigerant.

Then the storage bottle is put in a safe place, awaiting re-cycling or proper disposal.

So that is the refrigerant recovery process.

In our next posts we will complete the dismantling of the AC unit. Then we begin figuring out layout for the new machine, and preparing to braze up the new refrigerant circuit.

Best Regards,

-AC_Hacker

AC_Hacker · 11-19-09, 02:42 PM

I was Googling "compressor assisted heat recovery ventilator" and came upon this unusual set up...

I found it interesting that the person who posted this info is thinking very creatively about non-standard ways to use an air conditioner, but apparently, he hasn't yet summoned the gumption to go for a full radical hack.

BTW, the forum where the above link is posted forbids DIY talk...

* The very idea! *

Regards,

-AC_Hacker

%%%%%%%%%%%

11-09-09, 08:01 PM	#191
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	Refrigerant Extraction... Installing a 'Piercing Valve' Installing a 'Piercing Valve' To allow the capture and storage of the refrigerant. I have used a re usable piercing valve before, but I wasn't able to find it, so I went down to the neighborhood refrigeration supply shop and picked up the only one they had which was a braze-on model. This valve has a removable core, with a tiny plastic gasket, and a brass screw-on cap. The core must be removed, then the piercing valve body is brazed into place on the still-pressurized refrigerant line, then the core is inserted and the cap is screwed down tight, driving the point of the core through the refrigerant tubing. *( * * The core is removed before installation, because the heat of brazing will destroy it. * * )* Notice that I cleaned up the tube where the piercing valve will go, this makes brazing much easier. The coreless piercing valve is placed over the tube and a pair of pliers is used to snug the tabs around the tube. I put some flexible fireproof kiln material that I bought for this purpose, around the area where I will be brazing, to protect everything from the intense heat. Since my last very positive experiences with 5% Silver-Phosphorous brazing rod, I have been using it exclusively, with no flux, with very good results. Once the copper was glowing cherry red, I touched the brazing rod to it and it flowed around pretty well. I needed to do a wee bit of touch-up at the bottom, but it went much easier than I thought it would. So I waited several minutes, until I could comfortably hold on to the newly brazed piercing valve. Before I put in the core, I pulled a vacuum with a micron gauge attached, and quickly hit 330 microns, so I took that to be 'no leak'. Next, I removed the vacuum hose, and inserted the core with its tiny plastic gasket. Then I put the brass screw-on cap in and cranked it down with two small wrenches of appropriate sizes. This is the point when the core actually pierces the refrigerant line. There was no hiss or leak sound, or any sign of refrigerant oil to be seen. However, I did put a little spit over the end of the valve, and sure enough, it formed a bubble... slowly, but a bubble. I also noticed that the valve was becoming suspiciously cold, so there was a very small, slow leak happening... I suspect that if I put a small neoprene 'O-ring' inside the brass cap, and use assembly lube on the O-ring and also on the threads, I could probably stop the leak, but it was not a confidence builder. But it still give me a way to hook up my extraction equipment to the AC unit and extract the refrigerant, which was the whole point. So, I screwed the brass the cap on, and set about, getting my refrigerant extractor equipment ready... (* * * to be continued * * ) Regards, -AC_Hacker %%%%%%% Attached Thumbnails Last edited by AC_Hacker; 11-10-09 at 01:01 PM.. Reason: photos, details of procedure*

11-10-09, 01:20 PM	#192
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	Extraction Edit... Please note that I have re-edited the previous post by including several detailed photos and an expanded explanation of the procedure. More expanded steps in the extraction process are to follow... -AC_Hacker %%%%%%%

11-11-09, 05:42 PM	#194
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	Refrigerant Extraction, Making a Small Extraction Tank When we extract the refrigerant, we can't just let it drift off into space. In addition to being unlawful in many parts of the world, it is immoral in all parts of the world, as commercial non-organic refrigerants will cause global warming and/or destroy the ozone layer. This has adverse impact on all life, no matter what country you live in. So we need to make an 'extraction tank' to store our refrigerant in, temporarily or longer. This will allow us to reuse the refrigerant later, or we can take it to be properly recycled. Small AC units and de-humidifiers hold about a pound of refrigerant, which will fit handily inside an empty propane torch bottle. So what I did was convert a propane torch, the kind that screws onto a propane bottle, into a refrigerant extraction adapter. A few simple mods are in order: To enable refrigerant to go into the empty propane bottle, we need to remove the tiny ball that is in the stem at the bottom of the torch. I just unscrewed the stem and removed the ball, then put the stem back on, minus the ball. Next we need to remove the too-small orifice from the torch... The orifice is a small hole at the end of the torch tube. It is so small you might not be able to even see it. As I recall, I got some pliers and just unscrewed the orifice brass part and threw it away. (It could also be drilled out) Then I temporarily removed the needle valve from the torch because the heat of brazing will destroy any rubber sealing parts, and then I brazed on a 1/4 inch Schrader valve (Also removing the Schrader core before brazing). I didn't put the Schrader core back into the valve, because with the needle valve of the torch, there's not much need. The Schrader valves are used in the HVAC trade and come in various sizes, with 1/4 inch being referred to as "standard". They are really a bike or car inner-tube valve core fitted onto a flare fitting, and usually soldered or brazed onto a copper tube. They aren't too expensive, and it's not a bad idea to get several, you'll probably use them all. The propane bottle that we will use for our storage tank needs to be really empty of propane. If you shake it and can hear or feel any propane at all, there's too much propane. You should be able to put a known good, un-modified torch on the bottle, and attempt to ignite the torch in the normal manner, and be unable to light the torch because there is not enough propane. But, even after that, there is still propane in the bottle... So only after the 'fails-to-ignite' test, we put our newly-created adapter onto that bottle, attach a vacuum hose to it, and turn on our vacuum pump, making sure that the needle valve is open, so the last remaining propane can be evacuated... let the vacuum pump run and watch the vacuum gauge go down to full vacuum, then let it run for an additional 10 or 20 minutes minimum. Voilà!!, we now have a small, cheap extraction tank ready for service. The beauty of using propane bottles is that each one has it's own ball-valve built into the bottle to prevent gas from escaping. When you remove the torch from the bottle, you can hear the ball-valve snap into place. Make sure that when you recover your refrigerant, you don't over-fill the bottle. You want to leave a minimum of 1/2 to 1/3 empty. Refrigerant in the vapor state is compressible, but refrigerant in the liquid state is not. If a too-full bottle of refrigerant was allowed to get hot, there is a distinct danger that the refrigerant could expand and rupture the bottle, with unpredictible consequences... none of them pleasant. Stay on the too-safe side. Regards, -AC_HAcker (* * * more to follow * * ) Attached Thumbnails Last edited by AC_Hacker; 11-12-09 at 12:18 PM.. Reason: pictures, spelling, grammar...*

11-11-09, 06:29 PM	#196
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	"the fittings must be brazed" I can see how cryogenic temperatures could be a problem with rubber. I wonder if some other material might work better.?. (I've seen rubber balls fail to bounce.. They break like clay when too cold). Those "re-usable piercing valves" sound like the way to go.. After seeing your work above, I wonder how all that heat effects the refrigerant and the pressure inside the lines?? I know to keep my CO2 tanks cool..

11-18-09, 02:00 AM	#199
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	Refrigerant Extraction, Extraction and Storage This section will cover the extraction and storage process. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>> This blog thread is aimed at an international audience. Some aspects of vapor-compression servicing and modification are regulated in certain geographical areas. Other geographical areas are quite free in this respect. The reader of this blog is advised to find out what regulations may apply, if any, and act accordingly. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>>> As previously stated, When we extract the refrigerant, we can't just let it drift off into space. In addition to being unlawful in many parts of the world, it is immoral in all parts of the world, as commercial non-organic refrigerants will cause global warming and/or destroy the ozone layer. This has adverse impact on all life, no matter what country you live in. A refrigerant extractor should be used to capture and store the refrigerant. Such a device may be purchased new, purchased used, rented, borrowed or made by the reader. Xringer shared this video link for those who may want to make their own. These links may also be of interest to DIY recovery machine builders: how do i build a Refrigerant Recovery Unit [Archive] - XtremeSystems Forums DIY Refrigerant Recovery Machine! - Overclockers Forums Relentless haunting of pawn shops and ebay may turn up a reasonably priced unit. Luckily, Bruce-the-Pirate loaned me a recovery machine from his truly impressive store of tools. The top photo shows the Microvac unit. In the upper right hand part of that picture is the grey filter that the input vacuum hose connects to. On the opposite side of the top is a fitting to which the outlet vacuum hose attaches to. The bottom photo shows the vacuum hose connecting to the previously brazed Schrader valve on the AC unit. The other end of the hose attaches to the previously evacuated storage bottle in the photo below. Notice that the bottle is in the deep freeze to help reduce the volume of the vapor inside the bottle. I have used bowls of ice water for the same purpose, it worked just fine. The next photo shows the valve knobs on the Microvac. Basically, they are both turned to the "Self Evac" position and the unit is run until a full vacuum is pulled, as shown in the top photo below. Then the valve knobs are turned to the "Evacuation" position, and the needle valve on our storage bottle is opened. You will see deflection of the gauges as the refrigerant is pumped from the AC unit, through the Microvac, and into the storage bottle, as shown in the lower photo. The unit is run until the gauges indicate that all the refrigerant has been removed from the AC unit. Then the needle valve on the storage bottle is closed and the Microvac valve knobs are returned to the "Self Evac" position and allowed to run until a full vacuum is again reached. At this point, the microvac is turned off, the hoses are removed from the AC unit, the Microvac and the storage bottle. Then the adapter we made previously is unscrewed. You will hear a 'snap' as the ball valve in the bottle snaps into position, sealing the bottle of refrigerant. Then the storage bottle is put in a safe place, awaiting re-cycling or proper disposal. So that is the refrigerant recovery process. In our next posts we will complete the dismantling of the AC unit. Then we begin figuring out layout for the new machine, and preparing to braze up the new refrigerant circuit. Best Regards, -AC_Hacker Attached Thumbnails Last edited by AC_Hacker; 11-18-09 at 02:05 AM..

11-11-09, 05:36 PM	#193
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	That's a pretty neat way to install a Schrader valve on a piece of tubing. The first valve idea that popped into my mind, was one of those 'Piercing Valve' clamp-on things for adding a water supply to an ice maker. My guess is it might work up to around 200 PSI.. With water anyways.

11-17-09, 06:08 PM	#198
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	I just watched a couple of DIY videos. Some of the stuff shown and talked about sure sounded familiar.. How to fix your home's window air conditioner \| Appliances Video « Wonder How To How to make homemade Redneck freon reclaimer \| Appliances Video « Wonder How To There's a lot interesting stuff on the web these days..

11-19-09, 02:42 PM	#200
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	Doing Interesting Things With Air Conditioners... I was Googling "compressor assisted heat recovery ventilator" and came upon this unusual set up... I found it interesting that the person who posted this info is thinking very creatively about non-standard ways to use an air conditioner, but apparently, he hasn't yet summoned the gumption to go for a full radical hack. BTW, the forum where the above link is posted forbids DIY talk... * The very idea! * Regards, -AC_Hacker %%%%%%%%%%% Attached Thumbnails