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Unico systems - anyone work with these?

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Unico systems - anyone work with these? vh1117 07-08-2007
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Posted by vh1117 on July 8, 2007, 11:09 am
Sat. 7/7/7 service call western ma.

M: mb2436L S:# 0005a4936

These systems run at a lot lower cfm/ton then a normal AHU, dont they.
Here's my situation. Another tech was at the customers house yesterday
and found evap. iced up heavily and removed a totally glogged filter. I
had to return today to verify operation after a night of letting the evap
thaw.
He told me to look for a leak which he insisted they was. These were my
readings.... R-22 TXV
OAT 69'F Head psi 175 (92'F condensing) lig. line tmp 87'F
SAT 42'F
RAT 66'F Suct. psi 59 (33'F ) suct. line tmp 63'F ..suct. line
tmp out of evap 54'F.


Think this is low on charge??? I don't think it is but just looking for
other
inputs. My condenser-split (ambient to condensing tmp) isn't bad 23'F on
10 seer condenser, pretty clean too I can see right through the fins. 24'F
TD
across my indoor coil (these unico's run a lot lower cfm/ton airflow dont
they?) 30'F of superheat which hmm... not really much load on that coil
with
66'F return temp... not sure what to think of that. About 5'F of subcool
which I guess isn't all that bad, no name plate info regarding subcool on
the
condenser to what it's looking for. I'd think I would have a little more
with
not much load on the evap. Piping from the condenser goes straight through
the wall into the basement, not like a 40' vertical lift or anything.

J




Posted by Bubba on July 8, 2007, 11:39 am
wrote:

>Sat. 7/7/7 service call western ma.
>
>M: mb2436L S:# 0005a4936
>
> These systems run at a lot lower cfm/ton then a normal AHU, dont they.
>Here's my situation. Another tech was at the customers house yesterday
>and found evap. iced up heavily and removed a totally glogged filter. I
>had to return today to verify operation after a night of letting the evap
>thaw.
>He told me to look for a leak which he insisted they was. These were my
>readings.... R-22 TXV
>OAT 69'F Head psi 175 (92'F condensing) lig. line tmp 87'F
>SAT 42'F
>RAT 66'F Suct. psi 59 (33'F ) suct. line tmp 63'F ..suct. line
>tmp out of evap 54'F.
>
>
> Think this is low on charge??? I don't think it is but just looking for
>other
>inputs. My condenser-split (ambient to condensing tmp) isn't bad 23'F on
>10 seer condenser, pretty clean too I can see right through the fins. 24'F
>TD
>across my indoor coil (these unico's run a lot lower cfm/ton airflow dont
>they?) 30'F of superheat which hmm... not really much load on that coil
>with
>66'F return temp... not sure what to think of that. About 5'F of subcool
>which I guess isn't all that bad, no name plate info regarding subcool on
>the
>condenser to what it's looking for. I'd think I would have a little more
>with
>not much load on the evap. Piping from the condenser goes straight through
>the wall into the basement, not like a 40' vertical lift or anything.
>
> J
>
>
Your answer is simple. You just dont see it.
Here. Let me clarify it for you.
YOU have NO business being sent on that call. Call your boss up and
tell him to send someone out that knows how to properly assess a Unico
system. While you are telling him that, tell him to get you trained on
that type equipment.
Why should you be allowed to mess with someones system when you have
no idea if it is even charged properly??
If your friend called you and told you to come over and fill his
cavity would you do it?
Bubba

Posted by on July 8, 2007, 11:50 am
wrote:

>Sat. 7/7/7 service call western ma.
>
>M: mb2436L S:# 0005a4936
>
> These systems run at a lot lower cfm/ton then a normal AHU, dont they.
>Here's my situation. Another tech was at the customers house yesterday
>and found evap. iced up heavily and removed a totally glogged filter. I
>had to return today to verify operation after a night of letting the evap
>thaw.
>He told me to look for a leak which he insisted they was. These were my
>readings.... R-22 TXV
>OAT 69'F Head psi 175 (92'F condensing) lig. line tmp 87'F
>SAT 42'F
>RAT 66'F Suct. psi 59 (33'F ) suct. line tmp 63'F ..suct. line
>tmp out of evap 54'F.



http://www.unicosystem.com/media/pdfs/Bulletin%2030%2D020%20%282007%2D05%29.pdf

page 23 - 24

Your call. You're off the chart right now. SC i sfine, SH seems
high, BUT it may be OK. Delta is good, of course.

My guess - you're fine.



>
>
> Think this is low on charge??? I don't think it is but just looking for
>other
>inputs. My condenser-split (ambient to condensing tmp) isn't bad 23'F on
>10 seer condenser, pretty clean too I can see right through the fins. 24'F
>TD
>across my indoor coil (these unico's run a lot lower cfm/ton airflow dont
>they?) 30'F of superheat which hmm... not really much load on that coil
>with
>66'F return temp... not sure what to think of that. About 5'F of subcool
>which I guess isn't all that bad, no name plate info regarding subcool on
>the
>condenser to what it's looking for. I'd think I would have a little more
>with
>not much load on the evap. Piping from the condenser goes straight through
>the wall into the basement, not like a 40' vertical lift or anything.
>
> J
>
>

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Posted by The Freon Cowboy on July 8, 2007, 1:17 pm
yep, lower cfms and higher velocity , better dehumidification for given
tonnage
over conventoinal ahu's ,
typically lower suction pressure thatn standard ahus on the same refrigerant

and although im inlined to agree with bubba , your readings dont look bad to
me ,



>Sat. 7/7/7 service call western ma. wM: mb2436L S:# 0005a4936es These
systems run at a lot lower cfm/ton then a normal AHU, dont they.lHere's my
situation. Another tech was at the customers house yesterdaygand found evap.
iced up heavily and removed a totally glogged filter. Ishad to return today to
verify operation after a night of letting the evapFthaw.eHe told me to look
for a leak which he insisted they was. These were my3readings.... R-22
TXV3OAT 69'F Head psi 175 (92'F condensing) lig. line tmp 87'FrSAT
42'F RAT 66'F Suct. psi 59 (33'F ) suct. line tmp 63'F ..suct.
linebtmp out of evap 54'F.p) Think this is low on charge??? I don't think
it is but just looking foruothereinputs. My condenser-split (ambient to
condensing tmp) isn't bad 23'F ont10 seer condenser, pretty clean too I can
see right through the fins. 24'FdTDnacross my indoor coil (these unico's run a
lot lower cfm/ton airflow dont they?) 30'F of superheat which hmm... not
really much load on that coilrwith 66'F return temp... not sure what to think
of that. About 5'F of subcoolewhich I guess isn't all that bad, no name plate
info regarding subcool ongthe condenser to what it's looking for. I'd think I
would have a little moretwithanot much load on the evap. Piping from the
condenser goes straight through


Posted by B-Hate-Me on July 9, 2007, 7:40 am

> Sat. 7/7/7 service call western ma.
>
> M: mb2436L S:# 0005a4936
>
> These systems run at a lot lower cfm/ton then a normal AHU, dont they.
> Here's my situation. Another tech was at the customers house yesterday
> and found evap. iced up heavily and removed a totally glogged filter. I
> had to return today to verify operation after a night of letting the evap
> thaw.
> He told me to look for a leak which he insisted they was. These were my
> readings.... R-22 TXV
> OAT 69'F Head psi 175 (92'F condensing) lig. line tmp 87'F
> SAT 42'F
> RAT 66'F Suct. psi 59 (33'F ) suct. line tmp 63'F ..suct.
> line
> tmp out of evap 54'F.

I'd check the airflow and/or the condition of the evaporator coil.

30 degrees superheat is way too high for the listed conditions.



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