Efficiency: Piston vs. TXV

[Jeremy Martin]

Good evening.

What are the efficiency benefits of a TXV over a piston for the residential and light commercial split systems that I work on (1.5 to 5 ton systems in the northeast US)?

I always run up the head pressure to check superheat on piston systems so I can make sure they won't flood back on hot days. Basically, I'm charging for the hottest week of the year.

So every day that it's cooler than the conditions I simulated, the system is undercharged. Ergo, a piston isn't doing a very efficient job of cooling at lower ambient temperatures.

Whereas: A TXV will maintain a nice 10 or 12 degree superheat, give or take, under all reasonable conditions.

Isn't the compressor going to run a lot less at lower outdoor temps with a TXV? And if that is the case, won't a TXV pay itself off pretty quickly? And if THAT is the case, why isn't everybody selling systems with TXVs? Am I missing something here?

Thanks.

[Brian_UK]

It all comes down to "price".

If they can make it cheaper then they will.

[Jeremy Martin]

So you're saying the $100 upgrade would pay itself off in energy savings?

[davis22]

Hi friend,

Refering to the piston concepts I, munsif ali from pakistan , am submitting my theory for analysis of all those who have put the thread regarding pistons involved in referigeration technologies.

I was really delighted to see the website refrigeration-engineering.com, and I have become member of it. The importance of referigeration technlogies now days is undeniable. and when one is educated enough to understand mechanisms involved in referigeration machinery and can communicate his ideas and thoughts to other, then he must also start doing something worthwhile like taking to practical work and buying necessary tools.

when I saw split AC, one question came to my mind, why two cooling elements installed inside the room or compartment, can not run on one heat element installed outside the room.

I saw an animation of mechanism involved in circulating the referigerant gas in split AC on you tube and now want to put up few questions to you.

- Users of split AC, while installing both the pieces use additional metal pipes extending as long as 2 meters to 6 meters and sometimes 8 meters, due to non-availability of room for installing the heat element.

- now my question is if we can use additional metal pipes , then dont you think the timing of piston in compressor gets disturbed?

- now in case if the timing is not disturbed due to installation of additional metal pipes, and mechanical system has been designed in such a way, so that it keeps automatically circulating the referigerant gas through the cool providing element inside the room , then why not use two elements inside the room to run on one heat element installed outside the building.

- do you think that when it requires to attach additional metal pipes , do we need to increase the volume of referigerant gas other than required under manufacterurer's specification.


hoping a reply from your side.

Regards


MUNSIF ALI
0923313524436
88- B-M-C-H-S,
adjacent faran coperative housing society
karachi (sindh) Pakistan