Author Topic: Copper tubing! (Read 21708 times)

Ron · « **Reply #75 on:** July 05, 2009, 08:52:43 PM »

Quote from: Jim147 on July 05, 2009, 05:31:05 PM

For the little tubes I just score the outside with a small file and snap it off. If you don't cut all the way nothing gets in.

jim

+1 me too

280plus · « **Reply #76 on:** July 05, 2009, 11:50:04 PM »

me 3!

Nick1911 · « **Reply #77 on:** July 10, 2009, 12:07:56 AM »

Okay, charged to 70/240 psig.

Air coming out of the condensing unit - 120ish.

Superheat - still fairly high. Suction line isn't cool enough to gain dew.

Temp drop across evaporator, 10 degrees.

House doesn't seem to be cooling down.

Suggestions? Need more info?

Thanks!

280plus · « **Reply #78 on:** July 10, 2009, 06:32:27 AM »

What's the outdoor and outdoor temps? If the superheat is high the coil is starving for refrigerant which means one of two things. 1. You are still undercharged or 2. The expansion device is too small or is restricted somehow. I would suggest adding more juice but only like a pound at a time then wait 15-20 minutes and see what it does to your readings after each pound. The suction line SHOULD sweat. After 2-3 more pounds if the superheat doesn't start to come down you have other issues. What IS the superheat btw.

Nick1911 · « **Reply #79 on:** July 10, 2009, 09:16:35 AM »

Okay, I'll try adding a bit more this evening.

The air coming through the bottom of the indoor coil is quite cold - 50 degrees seemed to be a common reading. However the entire top half of the a coil isn't doing any cooling at all - air moving through it is the same temp as the return air duct.

Quote from: 280plus on July 10, 2009, 06:32:27 AM

What's the outdoor and outdoor temps?

Outdoor temp - 88 degrees
Indoor temp - 81 degrees
Temp coming out the registers - 71 degrees

Quote from: 280plus on July 10, 2009, 06:32:27 AM

What IS the superheat btw.

25 degrees, by my calculation
(70psig translates to 44 degrees F, suction line measures at about 69.5 degrees)

Jim147 · « **Reply #80 on:** July 10, 2009, 04:43:32 PM »

If you've had it running all day check to see if the coil is iced over. If it is turn on the furnace for a few minutes to clear it off.
Are you running this thing with a cover of some kind over the coil? If not cover with something while adding freon and taking readings. The ice will stop air flow through the coil and the missing cover will let air go around the coil. Both change your results some.
With the current 299% humidity level in this area, getting a full sweat patten on the evap coil should be easy.
Put some more refrigerant in it and let us know.

jim

280plus · « **Reply #81 on:** July 10, 2009, 05:23:56 PM »

yep, sounds like you are low. Take 88* add 30* and convert it to pressure. That's where your discharge pressure should be. I'm seeing ~253 PSI with regular old r-22 on a chart I found

Ron · « **Reply #82 on:** July 10, 2009, 09:50:45 PM »

Not only that but...

In my experience the non cfc blends tend to run much higher discharge pressures. So that "add 30" might be on the low end.

Jim147 · « **Reply #83 on:** July 11, 2009, 12:21:53 AM »

Is it fixxed yet?

jim

280plus · « **Reply #84 on:** July 11, 2009, 05:31:51 AM »

Quote from: Ron on July 10, 2009, 09:50:45 PM

Not only that but...

In my experience the non cfc blends tend to run much higher discharge pressures. So that "add 30" might be on the low end.

No, not really, the calculated temp would simply correspond to a higher pressure on the related chart. That's only a rule of thumb to get you in the ball park. If you get too much higher than that and still see no cooling you have other issues. Restricted expansion device maybe or air and noncondensibles in the system is another. Plugged condenser coil too.

Quote from: Jim147 on July 11, 2009, 12:21:53 AM

Is it fixxed yet?

jim

And if it's not the next classic question would be, "What's taking you so long?" We want you to share the whole experience.

Nick1911 · « **Reply #85 on:** July 14, 2009, 09:59:09 PM »

Quote from: Jim147 on July 11, 2009, 12:21:53 AM

Is it fixxed yet?

It is!

Quote from: 280plus on July 11, 2009, 05:31:51 AM

And if it's not the next classic question would be, "What's taking you so long?" We want you to share the whole experience.

Because I'm lazy!

I added another can of refrigerant. That brought the discharge pressure up to 255, and the suction pressure to 75 psig.

I get about a 12-15 degree drop across the evaporator. Not great, but it manages to keep the house comfortable.

I'll keep my eye on craigslist for a used a coil that has a TXV, or could easily be adapted to such.

Thanks again for all the help, guys!

280plus · « **Reply #86 on:** July 14, 2009, 10:25:32 PM »

The 75 PSI is a bit high which is why you're only getting the 12-15*. I suspect it is due to the fact that you have a 4 ton coil and a 3.5 ton condenser. I would think that as the house cools off the 75# should drop off a bit. Was the suction line sweating?

Nick1911 · « **Reply #87 on:** July 14, 2009, 10:30:03 PM »

As the house cooled down, yes - the suction line was sweating.

280plus · « **Reply #88 on:** July 14, 2009, 10:36:58 PM »

I wonder what would happen if you pinch off just one of those cap tubes. Each one is worth ~.67 tons. Let's see what Jim thinks of that nutty idea. I mean we're not talking stepping out of the box here, we're talking stepping ON the box and smashing it.

Then again, is there any way to slow down the air/evap fan? High suction CAN be caused by too much air moving over the evap. The evap fan motor may be multi speed and by just switching a wire you can adjust speed. NORMALLY the red wire is low, blue is med and black is high. If you still have a wiring diagram that's readable it will tell you. I'm assuming you know how to read one. ;-)

You know, I keep forgetting we're not using straight 22 here. maybe 75# is a good number. Check your chart and see how 75# corresponds to temp. You're looking for ~40*

280plus · « **Reply #89 on:** July 14, 2009, 10:37:58 PM »

Sweaty suction line is good. It means the evap is cold enough to remove moisture.

280plus · « **Reply #90 on:** July 14, 2009, 10:40:23 PM »

Could you post the corresponding chart again?

Nick1911 · « **Reply #91 on:** July 14, 2009, 10:41:22 PM »

Quote from: 280plus on July 14, 2009, 10:37:58 PM

Sweaty suction line is good. It means the evap is cold enough to remove moisture.

Oh lord, and is it ever doing so. The condensation line was drizzling like mad!

Nick1911 · « **Reply #92 on:** July 14, 2009, 10:41:57 PM »

http://www.befreetech.com/es22a_pressure_temp_chart.htm

280plus · « **Reply #93 on:** July 14, 2009, 10:50:28 PM »

Ahhh, lots of condensate means you should be ok. I notice on the chart though that 75# corresponds to 48* so that's a bit high. Outdoor was still in the 88* range? it's entirely possible the unit just needs time to catch up and as it does the suction pressure should drop off. 15* temp difference is not that bad really. I'd recheck it tomorrow morning and see where you are with suction pressure. If you feel like it that is, what with the laziness.

280plus · « **Reply #94 on:** July 14, 2009, 10:52:42 PM »

Translation: Just let it run and see what happens.

Now that THAT is done you may want to start working on an anti body eating robot robot.

Nick1911 · « **Reply #95 on:** July 14, 2009, 11:12:58 PM »

Quote from: 280plus on July 14, 2009, 10:52:42 PM

Translation: Just let it run and see what happens.

So you're telling me that I have to do nothing. That all I have to do, is just sit here and do nothing at all?

...

I think I can manage that!

Quote from: 280plus on July 14, 2009, 10:52:42 PM

Now that THAT is done you may want to start working on an anti body eating robot robot.

It's called an EMP device... Or maybe an HREF device. It's actually a fairly simple thing to do - a magnetron will easily convert high voltage DC to the RF spectrum. The trick is coming up with a magnetron that doesn't produce a frequency that resonates with the natural frequency of water. Such a device would still work as intended, but it would also cook the user.

Making a mounted device is easy, as a heck of a lot of power can be pulled from the average dwelling. (12-20kw) Portable devices are problematic because energy storage solutions are notoriously low density. The development of batteries has lagged far behind that of most other tech in the past 50 years.

Not that I would ever develop such a device. Or even theorize about it's development.

Jim147 · « **Reply #96 on:** July 15, 2009, 12:04:29 AM »

Quote from: 280plus on July 14, 2009, 10:36:58 PM

I wonder what would happen if you pinch off just one of those cap tubes. Each one is worth ~.67 tons. Let's see what Jim thinks of that nutty idea. I mean we're not talking stepping out of the box here, we're talking stepping ON the box and smashing it.

Then again, is there any way to slow down the air/evap fan? High suction CAN be caused by too much air moving over the evap. The evap fan motor may be multi speed and by just switching a wire you can adjust speed. NORMALLY the red wire is low, blue is med and black is high. If you still have a wiring diagram that's readable it will tell you. I'm assuming you know how to read one. ;-)

You know, I keep forgetting we're not using straight 22 here. maybe 75# is a good number. Check your chart and see how 75# corresponds to temp. You're looking for ~40*

I would want to take a very close look at that coil before putting a self made restriction in the system.

Quote from: Nick1911 on July 14, 2009, 10:41:22 PM

Oh lord, and is it ever doing so. The condensation line was drizzling like mad!

Yes the current humidity levels are great. I would like to see a little more temp diff. but let it get the house stabilized and see how it's doing.

Keep us posted.

jim

280plus · « **Reply #97 on:** July 15, 2009, 05:43:59 AM »

Quote

I would want to take a very close look at that coil before putting a self made restriction in the system.

In regards to what?

You have to wonder, so you pinch off a tube, suction pressure drops causing the rest of the coil to operate colder BUT you now have a section of the coil that passes the air through untreated. Would it end up being a "wash" because of that? Hmmmm,,,

Jim147 · « **Reply #98 on:** July 15, 2009, 10:26:21 AM »

Quote from: 280plus on July 15, 2009, 05:43:59 AM

In regards to what?

You have to wonder, so you pinch off a tube, suction pressure drops causing the rest of the coil to operate colder BUT you now have a section of the coil that passes the air through untreated. Would it end up being a "wash" because of that? Hmmmm,,,

That's my thought also. I would want to look to see how hard it would be to tie that section of coil in to the rest.
Something to think about but I think I can find a coil for him if it comes to that.

jim

280plus · « **Reply #99 on:** July 15, 2009, 06:01:32 PM »

Cool. Sounds like he's good given all the condensate but only time will tell.

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Author Topic: Copper tubing! (Read 21708 times)