What good does it do to upsize a coil?

[vapor_rush]

What does it do to upsize an indoor evap coil.

Example: 3 Ton condenser

4 Ton Evap coil

Does this increase the Seer rating?

Do you have to change the orifice size?

Thanks.

[Swampfox]

Originally posted by vapor_rush
What does it do to upsize an indoor evap coil.

Example: 3 Ton condenser

4 Ton Evap coil

Does this increase the Seer rating?

In many cases yes, many higher SEER units have a larger indoor coil, provided the manufacturer lists the coil/outdoor unit as a match.

Do you have to change the orifice size?

Yes, if it has a fixed orifice metering device it must be sized to the outdoor unit

[Gunnery Sergeant Hartman]

1st, you need to look into that particular piece of equipments spec book to see if its matched.
I know on my personal system I have a 2 ton heat pump w/ a 3 ton coil because I can get around 15 1/4 SEER from it.

[BaldLoonie]

Increased SEER, decreased latent capacity meaning higher humidity. Not something to do in a humid climate though many manufacturers do it rather than use a TXV on "normal" sized coil.

[HVAC Pro]

There have been many discussions about the pro's and con's of over and undersizing coils. Try the search feature above for hours of reading.

[41gasman]

BaldLoonie. So per the example
if I went with the 4 ton coil
with a 3 ton condenser with
a txv will this give a substantially
higher seer with out loosing
to much latent capacity?
When I first got into this trade
the guy I worked for did this
a lot. Minus the txv.He did not
no why he would go a half to one
ton over size on the indoor coil
just that thats what his dad
taught him to do.And they never
had any problems.He would use
a txv only if the whole system
scared him.Retro fit job big
house lousy ducting and it
had "alot of glass you know"
and with the hot afternoon sun
and all! I learned a lot from this
guy NOT because he was very good
OR knowledgeable.Bot because
he would take me to a job and
say "this is what I was thinking"
but do what you want to.Get
what you need from the supply
house.Then thereI would be
in front of the customer.....
Put a lot of pressure on me.
But I have a strong need to not
only be right.But right the first
time.That and I just hve to do
right by the customer.
41Gasman

[framehvac]

We oversize just a half of a ton I haven't looked into it but I was told that it wasn't good to oversize a hole ton but sometimes we do.This would be a good question for NormChris.

[aircooled53]

Lennox 36HC coil /w/txv on Lennox Horizontal Gas Furnace with American Standard 12.0 S.E.E.R. CONDENSER

I drop my electric bill in summer 65.00 a month from
10.0 s.e.e.r lennox 36acb change -out 2003

[git-r-dun]

Something else to keep in mind is to make sure you have a sufficient size blower in that furnace or else coil will freeze