Heating, Air Conditioning, Fridge, HVAC/Rusted coils


Dear Mr. Borgman
First off thank you for the opportunity that you offer to help with answers. I installed two complete brand new A/C units in my house 18 months ago, and I have a service contract that bring a technician twice a year. Yesterday they came for one of those maintenance services and the guy found that in one of the units the coils are badly rusted. He told me that they can use the guarantee but since that involves some other procedures that have out of pocket expenses he would prefer to something that would stop the corroding process. So he said that if they change the UV light bulb and seal all the ducts around the entire house (i think he called it mask sealing)that would solve the problem for ever. And if the coil keeps on rusting they then will execute the warranty. The guy was using the typical "Car Sales Technique" that made me think twice about his recommendation. What do you think? Is he correct? do the UV light bulbs has to do anything with that? How about the Mask sealing job? Thank you so much for any help that you can offer me.

 Where is the unit located?  Under the home, high humidity or damp area?  What I can tell you about UV is that it kills bacteria!  Rust is not a bacteria, it is a chemical process and even if the UV light could do something. it only affects direct line of sight contact.  So over half the coil would not get light directly on it, but either way look up rust on the computer and ask the Salesman about it?
 You have something else going on.  It could be sized wrong, installed wrong, charged with freon wrong.  A lot of things that take someone with boots on the ground to find out why.
 Did you have AC before?  If so did they rust?  I really need lots more info, but I would recommend you send me the numbers from the last service.  Here is what they should have taken down to do the tune up........
 High and Low pressure, liquid and vapor temperature, super heat and sub cooling, ( factory rating for sub cooling), ambient (outdoor) temperature, return air temp and supply temp.  If you send me all that and the equipment model and serial numbers I can help you a lot more

Heating, Air Conditioning, Fridge, HVAC

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john t. borgman


I am in Portland Oregon at Ben's heating 503-233-1779. I work days, so I can only answer early in the day or later in the evening. I only answer public questions for residential equipment. 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


I was lucky enough to start in this field almost 30 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.

Refrigeration Service Engineer's Society

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.

factory training in Lennox ,Rheem, Ruud ,Trane, Tempstar ,Carrier, Day&Night, Payne, Bryant, Coleman, Intertherm, York, Goodman, Ultra boilers, Unico, Mitsubishi,Sanyo, Taylor, Nicewonger, Navien. Associates degree in Refrigeration Engineering. Certified with Energy Department, Check-me Program, P.T.C.S (performance tested comfort systems ), have N.A.T.E. certifications in gas, a/c & heat pump.

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