Get Air Conditioning maintenance tips from 40 year veteran Bob Cochell.
Meet Bob Cochell, a forty-year HVAC contractor veteran who is an expert in all things heating and air conditioning related. Since opening Gulf Coast Air Systems in 1981, his air conditioning company has successfully completed 225,000 heating repairs and HVAC service calls, and 53,000 heating and AC installations. There is no one more qualified to answer your HVAC questions!
Over the years, Bob has heard some of the same heating repair and air conditioning service questions from his customers. That’s why he answered these common HVAC FAQs below. For more information, visit our Frequently Asked Questions page or call a Gulf Coast Air Systems technician today .
What is the difference in R22 and 410A in the units? Why did this change?
A: Both of these refrigerants are in common use throughout the world, the primary differences between the two are:
- R-22 is a single chemical compound, “Chlorodifluoromethane”, a leak can be “topped off” without negative effect, the leak should be repaired but a “top off” is allowed on residential equipment. The refrigerant can be charged in either liquid or vapor modes.
- R410a is a BLEND of three chemicals, each with a differing pressure and more importantly a different size molecule. If a leak occurs, the three components leak at a different rate therefore charging must be accomplished in the liquid mode and NO top off is allowed. Leaks require the removal and recycling of the entire refrigerant charge, installation of new drier(s) and recharging via liquid only.
- Price – due to an international agreement, the Montreal Protocol, the quantity of R-22 available in signatory countries (US is a signatory) the quantity of R-22 is restricted each year due to the chemical makeup of this refrigerant. R-22 contains a small amount of the element Chlorine which is suspect to damage the upper level Ozone layer in the stratosphere. As the quantity being produced is diminished each year our Federal EPA issues “Rights Letters” or the right to import or manufacture this refrigerant. Demand has outstripped supply and the price of R-22 has reached unprecedented high levels, a price increase of some 400% in the last two years. R410a has remained stable in price, however, the EPA is now voicing concern that it “may” have “Global Warming Potential” and is calling for an early phase-out of this refrigerant, perhaps beginning in 2016. The EPA is to conduct hearings with interested parties before making a final determination on the fate of R-410a.
- Substitutes – There are several “replacement” refrigerants making their way to the market. NU-22 or “New 22” is one such product. This is a blend of several chemicals and must be handled in a similar fashion to R-410a with regard to leaks and charging procedure. However, there are some uninformed servicers that are attempting to ADD NU-22 to an existing R-22 system without removing ALL the R-22 present in the system. This truly will not work, wild temperature and pressures will result. CAUTION, if you opt for NU-22 replacement for R-22 in a system there will be a penalty in capacity and efficiency and a clearly marked placard MUST be affixed so the correct charging chart is used to determine capacity and pressures.
- Oil – Why not just remove the R-22 and install R-410a? They use two TOTALLY different oils to lubricate the internal parts of the compressor and TXV (thermal expansion valve). R-22 uses simple mineral oil, non-toxic, safe, stable, etc. while R-410a uses a somewhat exotic Poly o Ester (POE) oil typically found in jet turbine engines. The refrigerant used MUST match the oil present in the system, which is one reason why you can’t replace the R-22 with R410a in a system. Additionally, the POE oil used with R-410a is “ultra-hydroscopic” and extreme care must be exercised to eliminate any moisture and water vapor from the system. The mineral oil used with an R-22 system is only mildly hydroscopic and the level of care with regard to the moisture contamination is vastly different. The correct tools, a seperate micron gauge and a tested vacuum pump capable of reaching pressures of 500-microns is a must for work with R-410 due to moisture concerns.
- Other Substitutes– May other refrigerants have been tested, one candidate for use is Propane; however it is extremely flammable therefore it has been ruled out for commercial use. There are many properties necessary for a successful refrigerant, while R-22 is being phased-out in the US, Canada and Western Europe it is still the most prevalent refrigerant in use in the world and costs very little on the world market. The Federal government strictly controls the importation of R-22 and has imprisoned violators of the “Clean Air Act” the statue which governs refrigerant use. BEWARE of R-22 that is offered at too low a price, either it is US refrigerant that may be contaminated with “blended refrigerants”, moisture or “bootlegged” from the world market with an unknown chemical makeup… it may not be “real” R-22, the results of either being catastrophic for the A/C system.
My filter doesn’t look dirty, should I change it?
A: Filtration is a long subject as there are a multitude of filters on the market, literally, “the good, the bad, and the UGLY”.
The best filter is a piece of cardboard; it lets nothing injurious to health through. However, the A/C won’t work so let’s try another approach.
Porosity, it the quantity and size of the “holes” in the filter that allow air passage. A typical flat 2’x2’x1” filter has some 4 square feet of surface area, where the same 5” deep “pleated media” filter contains 78 sq. ft. of surface area. With the greater surface area the size of the “holes” in the filter are smaller allowing it to capture more particles without a high pressure drop which is injurious to system performance and electric consumption.
The size particle a modern filter captures can be quite small, under 1-micron; the head of a pin being 9-microns therefore you may not “see” the dirt however the filter may be almost blocked. The only way to know is to measure the pressure drop across the filter with a Magnehelic Gauge which few homeowners possess. It is good practice to replace small square footage 1” thickness filters, under 5 sq ft, monthly when the system is in full operation (a month such as June) and the deeper “pleated” filters 4” and 5” at the recommended intervals which can be as long as 1-year depending on the conditions in the home. Items such as smoking and quantity of animals in the home effect the filter change regimen.
Why does water flow out of the PVC pipe from the indoor unit?
A: The air around us is made up of several components, Nitrogen, Oxygen, other elements but importantly “Water Vapor”. At times we “see” water vapor in the form of clouds or fog, it is always present in varying amounts and is “weather” driven. In Florida we are “dryer” in winter and very humid in summer.
The job of the A/C (Heat Pump) system is to not only lower temperature but to dehumidify the air, the combination of these two is the “Comfort Conditions” we experience.
The water flowing out the pipe is the water vapor that the system condensed from the indoor atmosphere into liquid water and is discharged out via the PVC (or other piping material) to be disposed of outside the “indoor comfort environment”. The quantity of this water is weather driven, more humidity – more water condensing, and as this pipe is “always wet” mold, algae and fungus like to grow in it therefore a biocide such as chlorine bleach or vinegar added to this water will keep the drain from “backing up”. ¼ to ½ cup of bleach, once per month will aid in keeping the drain line flowing smoothly.
What is the burning smell when I turn on my unit in heat for the first time?
A: There are many chemical substances in our air, particularly indoor air. When the heat is activated for the first time or the “first time in a long time” some of these chemical compounds along with dust particles have found their way to the indoor coil and heat element. As they are vaporized, burn off, they give a momentary smell which should subside within a few minutes. This phenomenon is also found when a “burner” on an electric stove is not used for some time and when activated releases an aroma. There is considerably greater “mass” with an air conditioning coil and supplemental heater than the burn on an electric range, therefore this effect takes greater time to diminish.