Aboutjohn t. borgman Expertise I work days, so I can only answer early in the day or later in the evening, I live in Oregon. I have been so good at all the other area's of hvac, I am probably the only hvac guy that does not know oil. ( lol ) I am very well versed in gas, electric and heat pumps and will only answer residential applications. I have been known the past decade or so, by my employers as the guy you send when no one can figure it out. Trouble shooting is my special. I understand the physics behind air flow, refrigerants and electricity. I understand programmable t-stats, zone controls, economizers, fossil fuel kits and the engineering thought process in the wiring and construction of residential equipment
Experience I was lucky enough to start in this field over 25 years ago as an installer, for a company that installed the best duct systems I have ever seen, even to this day. The best ,as far as understanding the way air really flows through a duct system, from the return air to the very last supply register . They also had great pride and the duct work was put in, not only to last 50 years, but to look exceptional. Then as I started doing service work, I was again fortunate that I found a 3 year engineering class being put on be a man that was the educational director for the Entire united states for a society called " the Refrigeration Service Engineering Society " And for the next 3 years I schooled at night and practiced what I learned during the day, a great advantage over schooling and then trying to remember it years later.. Versed in duct design manual J heat gain/loss calculations. Also experience in wine rooms and indoor swimming pool hvac & humidity controls
Publications I have 2 inventions that have gone through the process and been recorded at the National Institute of Standards and Technology from start to finish and thus been invited to national innovation workshops by the dept. of Commerce and the dept. of Energy. They are waste heat recovery devices that N.I.S.T approved as valid and am currently looking for marketing partners to get this product into the hands of consumers and make a BIG difference in Energy savings for every Household and Eatery and take a big bite in the the peak hours power consumption that face our Utilities companies.
Education/Credentials factory training in Lennox ,Rheem, Ruud ,Trane, Tempstar ,Carrier, Day&Night, Payne, Bryant, Coleman, Intertherm, Ultra boilers, Unico, Mitsubishi,Sanyo, Taylor, Nicewonger, . Associates degree in Refrigeration Engineering. Certified with Energy Department, Check-me Program, have N.A.T.E. certifications in gas, a/c & heat pump. Teach and apprentice at every company I work at.
Question QUESTION: I have 11 year old 5 Ton Carrier split-unit, just got 5-lbs Freon added, at least that's what the service man said. Apparently there is some leak - probably a significant one (had some freon added last year). Should I consider replacing the Unit including the evap coil?
ANSWER: Paul,
First Paul, if it was that low and had been added to last year they did you a disservice by not just finding the leak and fixing it. Your system total can't be more than 8 or 9 lbs. at the most. I would complain to the owner of that company, if they were aware that you had it added last year ( especially if they did it ) and ask them to defer that service call cost and come charge your system up with nitrogen on top of the charge taking it to 450 psi. At that pressure any and all leaks will be found just by listening. Then repaired and another nitrogen charge, verifying that there are no more leaks and you should get another 10 years out of the equipment.
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QUESTION: Thanks for the quick response. Didn't know that they can pressure test using Nitrogen. Lot of places they recommend to replace the unit if over 12 years to avoid recurring costs and they say leaks are not easy to fix - unless this is just a sales gimmick since they make much more money replacing.
The evap unit is in the attic, about 35 - 40 ft away, would that make the total Freon capacity to be around 12 lbs. Where do leaks normally take place, in the ground unit (compressor/condensor) and the evap unit? What about the tube (35' long) carrying Freon to the evap Unit in the attic, could it be anywhere in that tube which could be difficult to find?
Answer Paul,
Drive around the back of any Ma and Pa store and see equipment that is 40 to 50 years old with equipment that old also including the copper. Using nitrogen is the only way to find a leak. Sure they sell really nice electronic detectors, but even if it works and the guy holding knows what he is doing ( lots of false readings ) it only gets you to an area and takes forever. Nitrogen is what the new evap coil and line set come charged with and is what everyone worth a salt in this industry pressure tests with. And no, it is only partial ounces per foot for long lines after 30 feet. Leaks are most common at jonts, brazed joints, be it factory or job site related. Ask them why are they not easy to fix these leaks they speak of. The only place is where the copper meets aluminum if you have that type of coil. The rest is a piece of copper just like the one the will happily charge you to replace with your new equipment. I am telling you, that, 450 psi and you could find the leak, it doesn't take a rocket scientist to follow a loud hissssss.
