Tag: HVAC Corrosion

Technical Corner: “Did You Know – HVAC Corrosion”

Corrosion is found everywhere. Structures such as bridges, buildings, radio towers, and marine vessels all experience it. Corrosion results in billions of dollars per year worth of damage, and potential hazards to human life.

Studies on corrosion over the past centuries have been numerous. The National Association of Corrosion Engineers have for decades been deeply involved in how corrosion occurs and under what circumstances.

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One major area of corrosion many are too familiar with occurs in the HVAC field. In this area corrosion can take many forms and affect many areas. For example, a critical area of concern is often what a person doesn’t see.

Chilled water systems often corrode, causing metal deterioration and pitting on the inside of water piping, and inside condenser tubes in the chiller unit itself. Costs for retubing a chilled water condenser is expensive and time consuming. For this reason, one would be foolish not to monitor the corrosion in this closed system.
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Another area frequently attacked by corrosion are evaporator coils and outside condenser coils. Typically, corrosion of these coil types results in aluminum corrosion or whitish aluminum oxide deposits being seen.

Costs each year are huge. One major manufacturer of PTAC (packaged terminal air conditioners) lost over 8 million dollars in just one year due to warrantee replacements due to corrosion. Although the vast majority of corrosion related issues are located in coastal regions, corrosion also affect inland units as well. It is not uncommon for AC units in Illinois or other midwestern states to experience other types of corrosion.

Suffice it to say, in no cases I have run into over the past few decades were owners pleased with the prospect of replacing their units. Even the smaller PTAC units have replacement costs exceeding $1,200 or more each.

Not much for big business to handle when looked at as a single unit, but when one considers that many hotels have upwards of 300 – 400 units, you can see over $500,000 being spent. Not too many firms can withstand this type of expenditure every few years.
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There are many ways to handle and prevent corrosion. The easiest way is to prevent it from happening in the first place.

In part 2 of this blog, we will address solutions to a few of these corrosion types.

lynnLynn Burkhart is the founder and president of Controlled Release Technologies, Inc. located in Shelby, North Carolina. More information about the company, and its products, can be found at http://www.cleanac.com and by calling (800) 766-9057.

Technical Corner:How Professionals Work Smarter Not Harder on HVAC …. Part 2

Proper maintenance of HVAC air handlers helps the CFO or finance head, as well as occupants.   Saving money every month by getting the same amount of cooling for less money makes sense.  Certainly, if another provider of electricity came by the office and offered a 10% discount on electricity purchased by them, any owner would jump on the opportunity.

The reason why maintaining coils properly isn’t done is only because management does not realize the extent of funds they are currently wasting by cutting back on man-power for coil cleaning.  If it appears that it is too time-consuming, then other more technological methods developed over the past decade need to be looked at.

In our previous blog, we talked about how biofilms form on surfaces. Biofilms are interesting, mostly because they seldom are noticed and the average person is just unaware of them.

Indeed, they form on almost all surfaces and are not unique to HVAC interiors.

HVAC interiors offer something that most surfaces don’t see however, and that is a temperature controlled environment with moisture, darkness, and a constant supply of nutrients  from small particles in the air being pushed across the coils in amounts of millions of cubic feet each day.

We explained how technical studies by ASHRAE show coils within one year of cleaning are responsible for up to 20% or more increased energy costs than newly cleaned coils.  Since the HVAC energy use accounts for over 50% of a typical buildings electrical expenditures,  having clean coils would make for a much better bottom line in terms of energy usage.

But coil cleaning to remove the physical buildup of dirt and other contaminants may not make sense if manpower is on short supply, and it isn’t worth it, even with spending more energy dollars, to clean the coils often.   But there is a solution.

As most of you know, Controlled Release Technologies spends tens of thousands each year on research and development.  Since our founding in 1986 we have brought out more than a dozen innovative products that the marketplace had no access to prior to our development.  A major accomplishment was our development of First Strike MicroCoat ®.

First Strike MicroCoat ® keeps coils continuously clean for a year or more at a time without maintenance intervention or cleaning.   It was, and is today, a major breakthrough in technology.  We developed this product to handle concerns by many of our customers over odor control, and especially wasted energy they saw by using dirty insulated coils.

Another of your advantages with tis product is  it is water-based and  free of noxious petroleum products.   This makes it more environmentally se to use while at the same time being significantly more cost effective by removing extra labor for cleaning while decreasing your monthly energy bill.

Please do not hesitate to leave your comments or testimonials below.

Lynn Burkhart is the founder and president of Controlled Release Technologies, Inc. located in Shelby, North Carolina. More information about the company, and its products, can be found at http://www.cleanac.com and by calling (800) 766-9057.


Technical Corner: How Professionals Work Smarter Not Harder on HVAC …. Part I

Maintaining HVAC air handlers to obtain low cost of operations can be quite time consuming and use up available man-hours.  Management allocation of labor has always been minimal over the past few decades, but now restraints on hiring have been even more noticeable.  The result?

Many departments have cut back on necessary coil cleaning, keeping water collection pans free of bacteria and other microbials, and in some cases choosing to put off changing air filters.   While on the surface these things seem okay to cut back on, the actual fact is they cause more problems than they solve.  Of course the cutbacks seem to provide the owner with more cash flow.  But this is surely not the case.

Cutting back on maintenance items as above costs management more money rather than less.

Why?

A recent ASHRAE Journal reported a study that was completed in New York on HVAC units that had been cleaned a year previous.  What they found was to some surprising; others in the HVAC field might have considered the ASHRAE findings intuitive or expected.

Several air handlers had their coils cleaned after a one-year period.  The study found that the clean coils exhibited an energy savings of up to 20% or more than those coils that had been cleaned only one year before.   For several air handlers, this amounts to wasted financial expenditures of tens of thousands per year.   Balance that against keeping the coils clean throughout the year and one can see that saving a few man-hours does not really compare to this kind of wasted money.

The main culprit is biofilms.   Biofilms are very thin layers, in most instances, of bacteria and other microbes.  They tend to be sticky.   They grow on any surface, and growth is enhanced by the presence of high moisture and nutrients.

Because they are sticky, when any dirt or organic matter bypasses the filter or comes through the filter, the matter impacts upon the biofilms and may stick to the film.   Since the overwhelming amount of surface area is the cooling and heating coils, particles that impact and stick on the biofilms on these surfaces insulates the coils even further.   It is known that biofilms alone provide the same insulating affect as 5 times that amount of scale.

This is why coils that are apparently “clean” are financial detriments.  Knowing this, is it really smart to cut back on spending an hour or so cleaning coils?

But that is really only the start of the issues.   We all know bacteria and fungus create VOC’s or odors.  In many cases, these can be quite obnoxious.   Most managers might believe that since the air handlers are out of sight of tenants, no one really cares if they are in fairly good health.   We know of one air handler right now in the North East whose tenants in the building (lawyers by the way) have been complaining of odors for quite a few months.

Not withstanding all of the above, there lies another problem, and that is equipment sustainability.  How does having a clean HVAC unit related to the expected lifespan of the unit?  Most air handlers may cost anywhere from $25,000 to well over $100,000 to replace.   In the vast majority of cases, the owner does not hear this news until the unit is within a few weeks or months of replacement.   This can come about by the management not periodically inspecting the units for corrosion and fouled coils.

In the next blog, handling the above in a realistic way that makes sense will be reviewed. Please feel free to comment, we love to hear from our readers.

Lynn Burkhart is the founder and president of Controlled Release Technologies, Inc. located in Shelby, North Carolina. More information about the company, and its products, can be found at http://www.cleanac.com and by calling (800) 766-9057.


Technical Corner: Handling The Unknowable

It is well understood that air handlers are essentially an enclosure for heat transfer coils and system fans and filters.  It is also a fact that removing and replacement of these units is expensive – quite expensive.

Often, owners wisely elect to refurbish the AHU instead of replacing the unit.  This saves major dollars in almost all cases.  It is almost surprising to see a corroded AHU almost literally falling apart be turned into a usable piece of equipment with a considerable renewed life span, often greater than 15 years.

While the owner might do the refurbishment himself, he may also elect to have an outside contractor perform the refurbishment if he has no staff or limited maintenance support staff available.

Older units gradually lose their galvanizing (the zinc coating over the sheet steel), particular in those areas where there is a lot of water – like the condensate water collection pan, and the coil structural supports.   When corrosion occurs in these places, metal thins of course, and small perforations occur through the metal.  These holes are normally small, the size of pinheads.

They are exceeding difficult to see, if they can be seen at all, when the water is drained from the condensate pans.  This is because the pans sit on concrete and there is no backlight to see these small holes are there.  Larger ones yes, but the smaller ones no.

Because Pancrete was engineered to a water-like consistency to help it flow all over the pan surfaces and under the coils, it will also, like water, tend to seep out through pinholes.  Thus, one can  pour in Pancrete and have it slowly drain out of the pinholes, depending upon the size of the pinhole and the number of them.

Service technicians can hardly be blamed for not seeing the pinholes in the first place – they may be very small and unnoticeable, or the crew  may be working in the middle of the night to do the refurbishment, be in a hurry to finish and not notice them.

A significant method to solve these possible problems is to use the Panhole Filler.  It is designed to be an underlayment for Pancrete that Pancrete will seamlessly adhere to.   The new Panhole Filler will fill holes up to 50 mils in diameter so as to prevent Pancrete from running out of these small, unseen pinholes in the metal.

The Filler is rolled onto the horizontal surfaces first, let to set up, and then Pancrete is poured as usual.  Use of the Filler prevents any surprises so the job goes A to B.   Outside of wasting Pancrete that has leaked through, it invariably is an embarrassment to the refurbishing staff.

Call CRT customer service to learn more about how the new Panhole Filler can help you compete jobs faster with no surprises.

Lynn Burkhart is the founder and president of Controlled Release Technologies, Inc. located in Shelby, North Carolina. More information about the company, and its products, can be found at http://www.cleanac.com and by calling (800) 766-9057.

Technical Corner: Corrosion of HVAC Units

Corrosion is arguably one of the major reasons for expensive HVAC replacement. It affects all HVAC systems regardless of geographical location, but tends to be even more of a factor for HVAC units located along the seacoast.

Corrosion takes place often unnoticed by the user until it is too late. Examples are many. Outside coils or condenser coils exposed to morning salt fog on coastlines often turn whitish. Over time, sometimes in as little as 18 months, these coils are corroded so severely that the coil fins literally fall off the internal copper tubing. This essentially makes the unit useless.

HVAC units around industrial type cities where sulfur oxides or nitrous oxides are more abundant also corrode from exposure to this type of atmosphere.

In seeking to retard the corrosion of outside condenser coils, many users elect to coat the coil fins, a normally very expensive procedure. Coating condenser fins in the past required the coil assembly to be freighted out to a vendor who specialized in applying an epoxy-based coating on the coils. After that, the coil was shipped back and had to be reinstalled. The initial cost of coating could run from several hundred to several thousands of dollars depending upon coil size. Coatings were often greater than 1 mil or 2 in thickness that increased operating costs of the unit due to the insulating effect of the coil coating.

Fortunately, there are more economic and easier ways to protect coils from corrosion. Weatherproof Coil Shield is a unique product developed by us and tested in an accelerated weathering chamber for 4,000 hours. In chambers such as this, the coil is subjected to 24 hours per day of alternating exposure to salt fog, industrial atmosphere such as NOx and Sox, and infrared light. Accelerated weathering chambers are used to determine the effects of long-term exposure to known corrosive factors in a short term.

Since Weatherproof Coil Shield can be applied by any maintenance person in ten to fifteen minutes, its use makes it ideal for corrosion proofing in-place any outside coil. The coil should be washed first to remove any dirt and residual corrosion, and then our product is sprayed onto the coil. Re-spraying is recommended to be done yearly.

Even interior cooling coils develop corrosion. For the most part, this is caused by aggressive coil cleaners which attack system metals. Condensate can also cause corrosion, as well as microbial buildup (fungus and bacteria) on the coil surfaces.

Besides plain corrosion, buildup of bacteria and fungi insulate the cooling or evaporator coil, making it less efficient.

Here, the solution is patented First Strike Micro Coat. As with Weatherproof Coil Shield, this product is easy to use, and lasts for a year or more.

First Strike not only handles corrosion, but help maintain efficiency, lowering monthly operating costs.

Here, the solution is patented First Strike Micro Coat. As with Weatherproof Coil Shield, this product is easy to use, and lasts for a year or more.

First Strike not only handles corrosion, but help maintain efficiency, lowering monthly operating costs.

Adding First Strike Microcoat to your preventive maintenance program is a wise decision, lowering monthly energy bill while helping to assist indoor air quality.

Please feel free to comment or share your experiences with us.

Lynn Burkhart is the founder and president of Controlled Release Technologies, Inc. located in Shelby, North Carolina. More information about the company, and its products, can be found at http://www.cleanac.com and by calling (800) 766-9057.