TXV's

Wayco Wayne

install a TXV and charge by sub cooling. Variable air blowers are usually what we sell also. WW

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DennisDe

TXV's

Is it a good idea to have external TXV's added to the coil. I was thinking of having 2.5 ton 14 seer unit installed with matching coil and have a TXV added to the unit ...Good or Bad?...I was told that adding TXV's was not necessary, that it was old technology and that there is a tendency for leakage..

[Deleted User]

old technology?

When did we stop using TEV'S? A "fixed orifice" type metering device tends to give bigger pressure swings then a TEV. Also harder to properly charge the system. You can install a sight glass and charge the system with a TEV but not with a fixed orifice.Remember to remove the fixed orifice if installing a TEV, Can not use both. As far as leakage, if properly installed, there should be none. Most manufactures give the option of installing a TEV. Check the installation manual to see if it affect the SEER.

Mark J Strawcutter

TEV vs TXV

I've always used the terms interchangably. Is there a difference?

Also, shouldn't you charge a TEV/TSV system by subcooling and not just with the sightglass?

Mark

[Deleted User]

TEV vs TXV

> I've always used the terms interchangably. Is

> there a difference?

>

> Also, shouldn't you charge

> a TEV/TSV system by subcooling and not just with

> the sightglass?

>

> Mark

[Deleted User]

TEV vs TXV

No difference in terms. There are many ways to help in charging the system. Subcooling, superheat, amp draw, weight, the outdoor ambient plus 30 rule, ect. With a sightglass with a built in moisture indicator, early indications of a problem may be noticed. Also, depending on where the sightglass is installed (before or after the drier), an over-charge or restriction will be evident if this is a problem. Is a TEV needed? No. But, I feel it gives better system performance.

jim lockard

expansive valve

If your going to the effort of 14 seer machine w/txv and matching coil why not go whole hog with a variable speed air handler or 2 stage gas furnace with a fossil fuel kit. do not forget the sexy T-Stat.

Greg Swob

We do not install AC

without a TXV/ TEV. Not only that, but the brands we use either require or else 'highly recommend' a TXV, especially for the higher efficiency SEER units. A TXV will help obtain full efficiency of a unit.

Beware- as always, check your model's installation manual. Often when a TXV is installed, a hard start capacitor may also be required such as 'Kickstart' model, even with a quick pressure release type TXV. Your install manual will specify the details on this or contact the supplier for specifics. Kickstart is approved explicitly by one of our brand manufacturers - however, I do not mean to imply any one brand starting capacitor over another is better. Don't forget to remove the fixed orifice as mentioned prior.

Subcooling is the preferred method (again, per manufacturers of the models we install) to determine final refrigerant charge. Your maker will state which method is to be used. Greg

Kevin_12

Scroll Compressors

Never use a start kit with a Scroll compressor. Also the sub-cooling will be 8-10 degrees for a 14 seer. Also if you were to check with the manufacture they would highly recommend a txv to acheive 14 seer. Charge piston units by superheat only. And I would have to say , and I could be wrong, but I bet you need a varible speed blower to get 14 seer

Paul Mitchell

Why no hard start?



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jim lockard

Var. speed

you got to make sure you are up to full speed (400 cfm) when your checking the charge on a variable speed unit your you will be back. I like to charge txv with subcooling but somehow on cooling I can never get away without making sure I have 19/20 degrees across the coil, always seems to be the sure test of customer comfort.J. Lockard