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Techman

Techman

Joined on December 30, 2005

Last Post on May 17, 2013

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A hug ,a handshake and some tears.

@ May 17, 2013 12:55 PM in A hug ,a handshake and some tears.

I met Francisco Martin when he was 17 and in High School BOCES for HVACR. I hired him,I made him bring his "books" to work so we could "do it by the book". Then he went to HVACR College with Professor Silberstein as his instructor. Same thing,"bring your books" to work! We worked anytime he was not at school, we went to lots of Mfrg's classes/seminars together. Dam kid was a sponge for knowledge.We worked side by side 80% of the time So 5years later ,he's leaving, he's advancing, he's working for Trane as of Monday! Today being his last day ,I gave him an early day off, he put in 6 1/2 hrs , so take the rest of the day off. WITH PAY!. So our goodby, good luck ,handshake turned  into a goodby, good luck hug and there were even some goodby, good luck tears.!

Survey!

@ May 16, 2013 6:23 PM in Survey!

What brand of units have the recommended SubCool  amount in the unit nameplate tag? What are those #'s of SC? What is the lineset length limited to at the nametag SC rating? Trane's nametag rating is 8-10*SC and their tubing length is 25' ,otherwise consult the factory! What do you guys see?

Dry Ship

@ May 15, 2013 9:04 PM in Dry ship

 HeatingHelp.com!What is metering device? Evap above/below cond unit?

Before I flap my jaws.

@ May 15, 2013 7:57 PM in Dry ship

What is a "dry ship"? I was on Sub's and we had a "dry ship" ! (BOAT I MEAN)

Passing thru

@ May 15, 2013 6:43 PM in duct sizing

Back here for parts. Check this out.

Ductalators

@ May 15, 2013 4:53 PM in duct sizing

Going back to my very first reply to this thread - a real good one by the way PaulS.-  somewhere along the line I remember saying something along the line of "this is a starting point" and I finished with "this is a start". My R.S.E.S. -S.A.M.- Manual starts out with those #s - 0.10"w.g. and 0.05."w.g. THEN they go on to talk about "The Equal Friction Method" then Equivalent length, then TEL, then     "CORRECTED PRESSURE DROP" and a few more things. There is even a section "DUCT ROUGHNESS CORRECTION FACTORS" but I figured PaulS. didn't care about that part, yet! So lets all get together and have a "Burn the Ductalator Party" ! Gotta go on a service call.

Duct vs gas pressuse

@ May 15, 2013 4:18 AM in duct sizing

The gas press has to be the same if there is one appliance or 10 . The pipe size changes. If the 1st gas appliance is a big 1,000,000 BTU boiler the gas pipe is kinda big, then the next and only other appliance is a 5,000 BTU gas lamp . Then if the "proper sized gas pipe" is used on both devices, the pipe sizes are different but the duct press (I mean gas press)stays the same.

Spence.

@ May 14, 2013 5:30 PM in duct sizing

LOL here, you'll send me your stuff when you get your next non-14hr day . Really ? Summers happening!!! So maybe Halloween ? LOL w/ you!!!!!! At your convience, my friend!

Vertical

@ May 13, 2013 2:43 PM in Vertical Seperation limitations.

My goofy mistake, I wasn't reading the charts correctly. Vert Sep can be up to 56'.  Thanks , John @MCN  for helping.

Ducts

@ May 13, 2013 2:14 PM in duct sizing

Hi guys. Spence, I wasn't being sarcastic by saying that I would like to hear about duct methodology. So ,fire away,but don't use too many big words, OK, I carry a toolbox around all day. I have a book called "air diffusion dynamics" theory,design and application by Ralph G.Nevins, PhD.    DUDE I get confused so easily! I got the book in 74' and have not even come close to "mastering it". But, I keep trying!

How about this 3t system has a TEL of 100'.!

duct sizing

@ May 12, 2013 11:57 PM in duct sizing

duct sizing

@ May 12, 2013 11:57 PM in duct sizing

In my R.S.E.S. Service Application Manual (SAM) "The Equal Friction Method Of Duct Sizing" shows an example of a system requiring a 1000CFM ,using a blower  on medium speed w/  0.5 total ESP ,then the very 1st reduction in ESP is the Supply Trunk  rated at 0.10 ' w.g.  and the 2nd reduction in ESP is the Return Trunk rated at 0.05" w.g. . Carrier shows the same ST and RT  pressure readings. I'm checking ACCA but I think its the same. Maybe you are going CCW and I'm going CW to get to the same point. I like my math better, its what I was taught and its what I know. Now I DID NOT say the ENTIRE SUPPLY DUCT SYSTEM was sized for 0.10" w.g. I DID say the ST (0.10)/RT (0.05) were.  I would like to hear about duct methodology, sound interesting.

Here we go again!!

@ May 12, 2013 7:27 PM in duct sizing

JStar, what size duct is used for a 3t AC ,no hot water coil, no 4-5" thick filters(just the basic 1'' air filter that comes w/the unit), Equal friction method please. Normal velocities. Carrier AC Co. taught me " duct sizing" back in 1974 at a 2 week Carrier Basic AC School and then in 1979 at a 1 week" Carrier Heat Pump Specialist Certification School" they taught "duct sizing" again , but, I'm sure things are different today! In February 1976 Fedders AC CO had a 3day "Fedders Factory Authorization Certification Class" which included some duct sizing Then in  March 1976, a  Fedders 3day "Heat Pump Specialist Certification Class" and a R.S.E.S.( 2day class 1985)  also had "duct sizing classes" that I went to and in 2000 I went to a L.I.P.A(Long Island Power Authority ) I day "Residential Air Flow and Refrigerant Chargeing Class", but what do they know! Back in the day, each mechanic had to be "Carrier ( or others) H.P Certified " AND State certified (State of Ct.) as a  H.P. Specialist(1978) in order to "touch "a H.P., Those tests included a little Duct knowledge. And then in 1987 I went to a Ruud "Heat Pump Certification Class " for 2 days which included some "ducting" But, what the heck! I guess I missed a lot.

duct size

@ May 12, 2013 5:17 PM in duct sizing

If the duct was "properly sized" for a 3t system then no way will that duct be properly sized for a 3 1/2 t or a 4t system. Close may work! If the 3t was "properly sized" for the house then no way will " a large tonnage unit work properly.If the duct size was screwed up and the tonnage was also screwded up then maybe/might be. A KindaSorta "rule of thumb" (here we go again) ,400CFM per ton for AC ,450CFM per ton for heatpump. Now this is a "starting point", supply trunks are sized   at .10 " water colume and return ducts are sized using .05-.06-.08" w.c. Using the "Ductalator" will do the rest. So, 3t=1,200 CFM @ .10"w.c. is 15' round or 20" x 9.5" or 12" x 16" and return trunk will be 17"round at .05" w.c. or10" x 26" or 12" x 20" Knowing how the duct size was determined is  USUALLY 1 of two different duct methods . #1-Equal Friction or #2- Velocity Reduction. This is a "start".

Vertical Seperation Limitations.

@ May 12, 2013 3:57 PM in Vertical Seperation limitations.

My Rheem/Rudd books show a vertical heigh limitation as being 25' for most of their split cond units. What is it on the units that you put in? I see LOTS of "rule breakers" out there. What do you do for a "proper charging" then?

Vertical Height Limitations.

@ May 12, 2013 2:30 PM in What is a Nomograph Chart ?

In my newer Rheem/Rudd manuals I see many cond units are limited to 25' of vertical separation. I see LOTS of cond units that break that rule. What to do? What to do to get one those "rule breakers" up and running as well as possible!What are some of the "VHL" on the equipment that you guys sell?

Nomograph chart

@ May 12, 2013 1:32 PM in What is a Nomograph Chart ?

Hi Spence, Happy Mothers Day to you and yours! I totally agree with you about the info the mfrg gives in their guide lines, that is the 1st step in doing it right. I've been thru 23-30 schools/classes that say the very same thing. I AGREE, but,  it doesn't make sense to me that the SC on an AC w/the evap in the basement is the same as an evap way up there  above the ceiling in a 3 story house/office .IF the mfrgs magic SC # is good for that attic job then its also good for every other elevation under that .All bases covered! Simple!. So,  1st fl TXV inlet press would be almost = press at King valve,so maybe a SC of 1 is needed, 3rd fl attic TXV inlet press drop =  LL press drop + 1psi drop for every 2' of riser, around 12-13 SC is needed. As the LL backs up in the cond coil while the SC increases, the condensing space is decreased so the head goes up. Your way works for you and many, many, many others! My way works for me and only a few others!! Enjoy the day!!!
A couple of ice cold brews would have been nice during this conversation.

Professor Silberstein is a MAMMA's BOY!

@ May 11, 2013 7:20 PM in Professor Silberstein is a MAMMA's BOY!

So am I for that matter! Happy Mothers Day. Love em' while you can!

C.C.H.

@ May 9, 2013 11:44 PM in Suction line frosting??

Just ran across a Carrier unit ,the C.C.H.is disabled at 78*f.Humgph!!!!!

SubCooling

@ May 9, 2013 7:01 PM in What is SubCooling

Hay JStar, where did you get this chart? My computer screen is fuzzy or something. Those two identical AC systems have two very different SC's. due to that "static head" of 1 psi=2' for R22.

Nomograph

@ May 9, 2013 6:28 PM in What is a Nomograph Chart ?

Hi Spence, I am not sure if that charging chart is a Nomograph or not, But I was referring to this "Subcooling compensating chart" kindof nomograph chart. Carrier AC Co. has this chart in their "Handbook of Air Conditioning System Design" book. Knowing what the actual press is at the TXV is critical, yea,like anything on this chart isn't critical
OK you Wetheads, hydronics has a "static head" for that hot water pipe going "UP" to that 2nd-3rd-4th floor.What is it 1psi =2.31' ? Well, we ReferHeads  have 1psi=2' for R22. 

What is a Nomograph Chart ?

@ May 9, 2013 2:06 AM in What is a Nomograph Chart ?

It has something to do with SubCooling!
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