High Performance HVAC Air Conditioning Page 2
 HVAC Air Conditioning Quickpage jump links:
Changing the Air Conditioner Blower Motor
Water Leaks near the Air Conditioner Indoor Unit
Air Conditioner and Heating System Ductwork
Air Conditioning Maintenance Page Two
Changing an Air Conditioner Blower or Condenser Fan Motor
Labor (troubleshooting and repair of the air conditioner system) time (approximate): 1 1/2 to 3 hours depending on unit location and part availability
This is common in the summer. High heat and constant use causes old (and some new) air conditioner motors to burn up. There are several different types of air conditioner motors and when dealing with anything electrical the best replacement is an exact replacement. There is a contradiction to that phrase. If you have a shaded pole air conditioner motor in your air handler I recommend that it be replaced with a PSC motor. If you don't know what that terminology means, the HVAC tech should know. PSC motors are far more efficient for HVAC blower motor applications than shaded pole motors. Shaded pole air conditioner motors are a rare find (at least for me) but when they are found in blowers they should be replaced with PSC motors. Additionally, when replacing any PSC motor I recommend replacing the capacitor. If the air-handling unit is difficult to access it will take the HVAC tech more time to change the motor. Some motors can be carried on the truck but most have to be picked up from an HVAC parts supplier. There are HVAC companies with parts runners. Once the HVAC tech diagnoses the problem they call the parts runner. Sometimes, by the time the HVAC tech has the old motor pulled the parts runner has the new motor delivered. If your unit is equipped with a double shaft motor expect to pay up to $300.00 for a new motor. These double shafted motors are rare in HVAC residential units but they do exist. Out of about a hundred motors in 2001 I only had one that was double shafted.
Typically the air conditioner blower motor will be replaced with a stock blower motor from the HVAC supply store or from a stock blower motor on the truck. The blower motor may not be the same brand but it is important, and the HVAC technician should understand this, that the blower motor be matched for amp draw, voltage, RPM, diameter of motor for remounting in existing bracket, and motor direction whether it be clockwise or counter-clockwise. There are blower motors which are reversible with a simple wiring change and the bracket which is in the existing unit may not be able to be reused. Sometimes it also necessary to change the blower wheel also if this wheel is damage in any way or out of balance. The HVAC technician will be able to recognize all these things and offer quick efficient solutions.
Water Leaking Near the Inside HVAC Air Conditioning Air Handling Unit
Labor time (approximate): 1 hour in some cases, several hours in others
It is important for air conditioning preventive maintenance to be performed on your system to avoid problems. Water leaking near the air handling unit can be avoided with proper air conditioning preventive maintenance. Normally this is a very simple problem that can be fixed in less than 30 minutes. Here is a list of what can cause water around the outside of the air conditioning air handler unit.
- The black insulation (called Rubatex) has a tear in it or doesn't cover the entire suction line. This line normally (in Air Conditioning air condition mode) operates below the dew point and will sweat if it is not insulated. It must have a sealed vapor barrier to be effective.
- The insulation surrounding the air handler supply transition or ductwork is torn. The supply transition and duct can operate (under the right conditions) below the dew point and sweat. It is important that the transition have a vapor barrier around it. This scenario is especially true for those that have oversized units.
- The condensation drain line is plugged. Air handling units in attics should have a secondary condensation pan in case the primary condensation pan overflows. Occasionally, the secondary condensation pan will also clog and not drain. Water builds up in the ceiling and eventually there will be a drip if the homeowner is lucky. If no drip, then eventually the entire ceiling will fall. In the attic I always recommend a float switch installed in the secondary air conditioning condensation drain pan. If the secondary condensation pan fills, the float switch will rise and cut the whole air conitioning unit off. This will force the homeowner to look for a problem or call an HVAC technician. In this case, with the float switch, the problem can be rectified before water damage occurs. Algae or a foreign obstruction such as mulch or potting soil can plug condensation drain lines. These air conditioning condensation drain lines (either black plastic or white plastic looking pipes) usually drain out somewhere at the base of the house into a flower garden. Make sure mulch or soil doesn't plug these condensation lines up. Adding algae treatment to the lines or pans can prevent algae. Some people pour bleach in the evaporator condensation pans once a year. Whatever the way you use to prevent it from growing in your evaporator condensation pan, know that if steps aren't taken to prevent algae growth, it will eventually plug the condensation lines.
- If the filter is extremely clogged, a duct is collapsed, the evaporator coils are plugged with dirt or dust because no filter was kept in the system, or there is a low charge of Freon, the evaporator coil will freeze. When it thaws, it will overwhelm the evaporator condensation pan and leak outside the air handling unit.
- Rust. Some evaporator condensation pans are made of metal and can rust through over the years of use. In certain cases, the entire air handling unit must be changed out. In other cases the evaporator coils and evaporator condensation pan must be changed. Normally if the air handler unit is old enough to have a rusted evaporator condensation pan that leaks, it is time to change the air handling unit.
- Unit or Drain Pan Slope. If the evaporator drain pan is not sloped toward the drain the water will not drain from the evaporator pan properly. Additionally, the condensation drain piping must be sloped.
Air Conditioner and Heating System Ductwork
 A good consideration when replacing the air conditioning system is the duct work. Duct work seems to be the most ignored part of an HVAC system but is a very important consideration in this age of new technology and higher energy efficient equipment being developed and manufactured. You can have the most energy efficient engine but if its in an old 60 or 70’s model car your efficiency is going to suffer. The same is true with HVAC systems. You can have the most energy efficient compressor available on the market but if your duct work is leaky or your house or business is not properly insulated that high efficient system you just spent big dollars on is wasted money. For more insight on HVAC ductowrk see the High Performance HVAC Ductwork Page.
Imagine, if you will, for a moment, that you had a sprinkler hooked up to a water hose. Let us say that the sprinkler was brand new and the hose was twenty years old. The hose definitely suffers from age and shows it with dry rot and a few attempted patches with duct tape (technically referred as sixty mile per tape). You hook this hose up to the sprinkler and the hose bib on the side of your house. You turn it on and the sprinkler comes to life, although a life that seemed to deliver less of a quantity of water than you expected from this state of the art, latest design in sprinkler system. You are mad. Angry that it doesn't work the way the package said it would work. You call the 800 number on the box that it came in and tell the manufacturing representative of the sprinkler company that the sprinkler is a piece of (expletive left out here in consideration of decency standards). The representative asks a few questions and listens intently to your answers. The representative asks you to try a simple procedure and then call him back directly after checking the hose from the hose bib to the sprinkler. You follow the recommendation and start at the hose bib on the side of your house. It is leaking at the connection and at the first and third places where duct tape was used. It is leaking profusely in several places. You find another leak down the way a little from the third attempted duct tape repair and then a fourth and fifth leak. You then say to yourself, "Dang! I probably should have grabbed a new hose with this high dollar solid-state state of the art sprinkler system I purchased." Meanwhile the representative is discussing this with his other representative members of the sprinkler company technical staff and anxiously awaiting you to call him back. You go and purchase a new hose, hook it up, and the new sprinkler works as advertised. You are now happy and have completely forgot about calling the representative back. This same scenario can be compared with purchasing any HVAC system and hooking it up to old leaking duct work. You simply are not going to deliver the air necessary to make the system as efficient as promised. By honestly evaluating all the parameters involved and taking action to repair or replace deficiencies you can get the efficiency out of the system you purchase(d) (just like the new sprinkler system). Replace that leaking duct work and watch your energy bills drop significantly. And last but not least, don't leave a manufacturer's representative anxiously suffering................awaiting your return call.
It is also important when these HVAC systems are installed that they receive a proper commissioning and start-up by a qualified HVAC technician to ensure that they are working as designed. This typically involves checking out the whole HVAC system to make sure everything is working as efficiently as possible as designed and promised when you signed the contract for the new system. Just remember, as the cost of energy rises it becomes more and more critical to make sure the whole HVAC system works together as efficiently as possible as per design. Follow those little nuggets of advice and you will save money and see your energy bills decrease. Information like this can save you tons of dollars in the future in HVAC energy costs. Use it to your advantage and save that $30.00 to $40.00 dollars a month so in the future you won't suffer temperature-wise or financial-wise.
Your Resource for HVAC Air Conditioner Repair Information
High Performance HVAC
Additional related links to help you with Air Conditioning and Heat Pumps:
Air Handlers | Condensing Units | HVAC Ductwork | Filters | Thermostats | High Performance HVAC Home
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