To Easy HUH

Originally Posted By: cbottger
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Okay guys that last question was to easy lets get a little more complicated.


There is a system in use today that is referred to as a Pump Down System not very common in residential systems but have seen them in use on homes. They are called pump down because of the type of controls used in their operation on and off cycles. My question is what are the two specific controls that must be present and what do they control.

And lets get a little more complicated what advantage or disadvantage could a pump down type system have over a non-pump down system.


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Don't argue with an idiot someone watching may not be able to tell the difference.

Originally Posted By: dhadler
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I was just starting to feel a little cocky about that last question I got right and you go and blow my mind with this one!


That's way over this little inspectors head.... Maybe David can give us a picture of a jet buzzing over my head ![icon_question.gif](upload://t2zemjDOQRADd4xSC3xOot86t0m.gif)

After seeing Davids pictures of the snow we may not see many cartoons for a couple of days while he's digging out

You got to love sunny Alberta...We are in a chinook. Sunny skies, snow all melted, and 56 degrees today! I'm getting the itch to get the mower out


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Darrell Hadler
Five Star Home Inspections
Medicine Hat, Alberta CANADA

Originally Posted By: dbowers
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Charley -


I'm kinda curious. I've got a degree in HVAC and 25 years in home inspection. I've never heard anyone call a residential A/C system of any kind a "pump-down system".

In commercial 20 years ago when doing certain services we would "pump the system down". Is there another name for this residential A/C or is this a local name you use - wherever you're from.


Originally Posted By: Dean Call
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Liquid Line Solenoid Valve


Low Pressure Switch


Thermostat closes the lliquid line solenoid which pumps refrigerant into high side and LPS cycles unit.

Unit needs no crankcase heat which makes the SEER higher.

Not too many around in residential applications.


Originally Posted By: Blaine Wiley
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Quote:
Liquid Line Solenoid Valve
Low Pressure Switch


These two items on most air conditioners and heat pumps. They are not unusual.

I, like Dan have never heard of anything called a "pump down" system, but have pumped down many systems before adding refrigerant!

I have also installed heat pumps on "pump ups" but that is a horse of a different color to be certain! ![icon_biggrin.gif](upload://iKNGSw3qcRIEmXySa8gItY6Gczg.gif)


Originally Posted By: dedwards
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I thought it was just me. I even pulled out my text books and couldn’t find a single referal to a pump down system. I thought of pressure switches but that was just a swag and not a real confident one.


Originally Posted By: mbartels
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No reply from Charley?



www.overbrookhomeinspection.com


It’s not over till you’re underground

Originally Posted By: cbottger
This post was automatically imported from our archived forum.



Sorry guys my plate has been overflowing.


Pumps down system was kind of a play with words on my part trying to disguise my true true thoughts hoping to make you think a little harder.


Pump downs are not particularly wide spread but can be anywhere not just in my area. It is just one of many forms of zone Cooling.

I will describe just one example here. Lets say you have two furnaces two A-coils and just one condensing unit sized for both A-coils. I hope IF you ever see this set up that you would not report that someone has stolen one of the condensing units : ![icon_wink.gif](upload://ssT9V5t45yjlgXqiFRXL04eXtqw.gif) : The A-coils would have as described above a liquid line solenoid valve just before the coil and would be controlled strictly from the thermostat. There will be no low voltage wires between the furnace and the outside unit. The low pressure switch not to be confused with the low pressure safety switch is wired to start and stop the compressor from pressure only. The LP switch becomes an operating control for the compressor contactor and opens roughly at 5 psig and closes at 35 to 40 Psig. This pressure is determined by the opening and closing of the liquid line solenoid valve controlled open when ever the thermostat calls for cooling from either either or both A-coils

This can also generate another question I will wait to see if someone comments on the two coils and one condensing unit??????

Thanks for waiting I am old and slow.


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Don't argue with an idiot someone watching may not be able to tell the difference.

Originally Posted By: cbottger
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Blaine


Would you run that horse by again I did not catch its color. Pump ups.


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Don't argue with an idiot someone watching may not be able to tell the difference.