Mitsubishi Electric Updates and Applications

Hello Everyone! As the HVAC industry changes so does the Mitsubishi Electric line- up. I would like to take a moment to introduce some of the newest Mitsubishi units.

PUY-6 P series cooling only unit: Mitsubishi released the -6 cooling only P series unit. This unit has the ability to run in cooling mode down to -20 degrees outside (with the use of the 3 piece wind baffle). This makes it a great option for server rooms where non-critical cooling is needed.

MXZ Multi-Zone Hyper-Heat units: Yes, that’s right! A multi zone unit that is hyper heat! This has the ability to provide heating down to -13 degrees or lower. They can provide 100% capacity at 5 degrees.

MVZ Air Handler: Mitsubishi has finally released their air handler. This is available in 12, 18, 24, 30, & 36 KBTU’S. This unit must be teamed up with their multi zone unit. This can be used to replace an existing air handler, and match to a Mitsubishi outdoor unit.

Thermostat interface: The interface allows the usage of a conventional 2 heat 2 cool thermostat. The homeowner can then use a thermostat that they are comfort- able with, or one they prefer the look of.

Kumo Cloud: The Kumo cloud is Mitsubishi’s wireless app-based interface. You can download the app and control your equipment by your phone or tablet.

6,000BTU one to one Hyper-Heat Heat Pump: When a 9,000 is just too big, Mitsubishi has released their 6,000 BTU hyper heat system.

MFZ-KJ floor mount 1 to 1 Hyper-Heat system: An excellent option for the home where a wall mount system won’t t. Available in 9, 12, 15 & 18 KBTU’s

That sums up the new releases in the land of Mitsubishi. These systems can be ordered if it is not in our current inventory. As always, feel free to contact the Famous Supply Technical Support department if you have any questions.

Jeff Rosenblum
Technical Support
17 Years Industry Experience
Cell (330) 962-2491

Air Conditioner Terminology

Hello all! It seems that the air conditioning season is upon us (finally)! As such, I figured this would be a good time to review some AC terminology. As always, if you need
any help please feel free to call the Famous Supply Tech Support Department at 330.475.8230.

  • Superheat: The amount of heat added to a substance above its boiling point. Superheat happens in the evaporator. Once the refrigerant boils o , it continues to absorb heat.
  • Subcooling: The amount of heat removed from a substance below its dew point. Subcooling takes place in the condenser. As the refrigerant condenses, it continues to be cooled o below its dew point.
  • Metering Device: This causes a drop in refrigerant pressure. When we drop the pressure of refrigerant, the temperature also drops. We use this idea in order to absorb heat from the house. Typical metering devices include the TXV, piston (fixed bore), capillary tube, and LEV.
  • Compressor: This is what raises the pressure of the refrigerant. When we raise the pressure, we also raise the temperature. We raise it above the outdoor ambient temperature so we can use the outdoor air to cool the refrigerant and provide subcooling.
  • Temperature Drop: This is the return air temperature minus the supply temperature.
  • Accumulator: This is sometimes used in air conditioners to capture any liquid refrigerant that may make its way back to the compressor. Liquid can cause damage to the compressor.
  • Crankcase Heater: This is sometimes added to an air conditioner. The purpose of this is to keep the compressor warm to avoid refrigerant migration in the oil. When refrigerant
migrates into the oil and the compressor starts, it causes the coil to foam. This provides inadequate lubrication for the compressor.

Jeff Rosenblum
Technical Support
17 Years Industry Experience
Cell (330) 962-2491

Why Do Evaporator Coils Fail?

We have all seen or diagnosed a bad or poorly performing evaporator coil. Over my years in the eld, I have diagnosed bad coils and the reasons why they fail can be surprising. So why do they fail? Here are a few things we have seen.

Coil plugging. When filters are neglected, the dirt can bypass the filter and plug up the evaporator coil. This will restrict the airflow and cause poor heat transfer. How do you combat this problem? Maintenance and proper filter design will usually solve this. Change the filter often, make sure it is sized correctly and the static pressure drop is not excessive, and verify there is not air bypassing the filter.

Vibration. If the coil is sitting on top of an air handler and the blower is out of balance, the vibration can cause the coils to crack and fail. Make sure there is not excessive vibration being transmitted through the system.

Corrosion. This has been a big one lately. We all hear about corrosion of coils. This
 is a big reason why they fail. Sometimes, if the coil is in a corrosive environment, a coated coil may be needed to resolve this. Look at where this system will be installed and take the necessary precautions.

Freeze ups. Allowing the coil to freeze and thaw and freeze and thaw several times can cause failures with the coil. I always tell people that if ice can move a mountain it can crack a coil. Make sure the refrigerant charge is correct and most importantly, the airflow is right.

System Design. If the system was never properly designed right in the first place, or the wrong coil was chosen for the application, you can expect the coil to fail well before its time comes.

So these are 5 reasons why a coil can fail. As always,
if you have any questions please feel free to contact the Famous Supply HVAC Tech department.

Jeff Rosenblum
Technical Support
17 Years Industry Experience
Cell (330) 962-2491

Why Use a Start Assist Device On Your Compressor

Many times we receive questions as to why someone would want to install a start capacitor (5-2-1). There are several reasons why this would be beneficial. As a compressor ages it may become more di cult to start. The windings may be ne, and once it’s running it operates properly, however, sometimes it just doesn’t want to get going. Oftentimes, adding a start assist device can give the compressor a bit of a boost.

This same theory applies to new units where the compressor may have a di cult time starting. Many times technicians think the compressor needs replaced, so why would a new unit need a start cap? Oftentimes, with long line sets or TXV’s, a start cap is recommended, and newer compressors are built with closer tolerances. As we try to manufacture units with more efficiency and less chance of bypass gas (which robs efficiency) we end up making the compressor tighter. Just because a new compressor doesn’t start, doesn’t mean it’s bad. Sometimes a little boost is all it needs. Just like us, we need co ee to get us going, a compressor needs a start assist to “wake up”.

Some of the benefits of a start assist are less wear and tear on capacitors, less light dimming on startup, and reducing the chance of a breaker tripping on start up. Before you condemn a compressor, try a Start assist (5-2-1).

I was told back in the day that start assists are only for failing units. This is not true. They can be used on new and existing units without problem. I have used them successfully for years. So before you say a seized compressor must be replaced, try a 5-2-1. You may be surprised by the results.

Jeff Rosenblum
Technical Support
17 Years Industry Experience
Cell (330) 962-2491

Sizing Equipment

We often get asked, “What size furnace/AC do I need?” The answer is not as simple as just knowing the square footage. There is a lot that goes into figuring out the right size.

So, what information is needed to figure out the right size? First, we recommend you use the Manual J sizing program. Second, you will need to know some key points.

  • House/building square footage      •  People load
  • Number and size of windows          • Additional load (lights, computers etc.)
  • Outside exposures 
                            • Unconditioned Spaces
  • Amount of insulation throughout the house • Weather info for the area
  • Number and type of doors 
              • Solar Gain
  • Amount of infiltration air 

               • Ventilation
  • Which way the house faces 
             • Humidity

This may seem like a lot of info in order to size equipment, but figuring out the design load is very important. If the system is too large, it can have a very short run time, may not humidify or de-humidify correctly, and the system will be inefficient. If it is too small, it may never satisfy the load of the building, which leads to being uncomfortable, and it is also inefficient. Either way will reduce the life of the equipment. Guessing the size is never the answer. Size the system the right way and keep your customers comfortable and happy!

Jeff Rosenblum
Technical Support
17 Years Industry Experience
Cell (330) 962-2491

Choosing the Proper Mitsubishi Electric System

I have received several questions regarding which Mitsubishi system would be appropriate for their application. Since Mitsubishi systems can t in a wide range of applications, selecting the right one can sometimes be a daunting task. There are a few key things to consider when selecting the right system.

Where is this unit going to be used? If it is in a commercial system, we recommend using the P series system. This system gives you the ability to link up to 16 systems to a common control. The P series is also the unit to use for non-critical server rooms because of its low ambient cooling capability. If it is a residential home/sunroom/ addition, an M series may be the better choice.

What size system do you need? A load calculation must be done in order to decide which size is best.

Is this going to be a multi zone system? Look around and see if there are other areas that can be covered. Usually, a simple question to the homeowner of “are there any other areas of concern?” will point you in the right direction.

Unit location is a key thing to look at. Where is the indoor unit going to be mounted? Will you need a condensate pump? How long is the line set going to be? Where will the outdoor unit sit? We must nd out where everything will be located to avoid potential setbacks.

Do you have enough power for the system? A quick look at the main breaker panel will tell you.

These are just a few of the things to pay attention to when considering a Mitsubishi system. Once you have all the necessary questions answered, then you can have a better idea of what system will be best for your application. If you need assistance in selecting the right Mitsubishi system please feel free to call the Famous Supply tech department at 330-962-2491

Jeff Rosenblum
Technical Support
17 Years Industry Experience
Cell (330) 962-2491

Test in-Test out

When I started in the HVAC industry, I was taught a method of testing that has served me well for several years. It’s called “Test in-Test out”.

What exactly is Test in-Test out? When diagnosing an issue with the equipment, many times we make changes and head on to the next job. How do we know
if the changes we made actually made a difference? Use the procedure of Test in-Test out. When you originally diagnosed the equipment you had a certain set of readings (pressure, voltage, etc.). Once you perform the needed changes, retest everything and compare your readings. Did anything change? If not, then the problem may not be completely resolved.

Here’s an example: If you check a pressure switch because it is not closing, you may find out that the inducer is only pulling .3”
wc, and the switch needs .9” wc to close. You look
deeper into the system and realize that there is a dip in the exhaust pipe that is collecting water. Once the repairs are made and the system is back in operation, retest to verify that the repairs you made have significantly changed your readings.

Using this procedure will give you and your client peace of mind that you did everything to resolve their issue.

Jeff Rosenblum
Technical Support
17 Years Industry Experience
Cell (330) 962-2491

S.B. 78 (Licensing Cleanup Bill) and
 H.B. 486 (Ohio Business Compliance Initiative)

As you may know, the Kasich Administration, through the Department of Commerce and OCILB, has changed regulation. Due to this, the Governor signed S.B. 78, which took effect on September 17, 2014, and H.B. 486, which OCILB will begin on January 1, 2016.

Ohio Business Compliance Incentive

H.B. 486 authorizes the Ohio Business Compliance Incentive Program, OCILB
will amend the current continuing education requirements and license renewal schedule for licensees by recognizing and rewarding licensees who are compliant businesses, while not reducing or easing the standards that these businesses must comply with.

The Ohio Business Compliance Incentive Program has three primary goals:

  • To recognize businesses who demonstrate a long, consistent pattern of 
compliance with the law and regulations;
  • To reward those businesses by reducing some or all of their costs associated 
with compliance or reduce the amount of regular inspections; and
  • To “get out of the way” of businesses so they can thrive, contribute to Ohio’s 
economy and continue to provide jobs to Ohioans.

Beginning January 1, 2016; H.B. 486 allows those contractors in good standing
to renew every year, or every three years. Forms for license renewals beginning January 1, 2016 will allow those contractors to check ‘1-year’ or ‘3-year’ renewals. H.B. 486 also allows contractors in good standing to take 8 hours of consistent education instead of 10. If the contractor chooses ‘1-year’, he will pay $60 per license, and 8 hours will be due at the end of his renewal period. If the contractor chooses ‘3-years’, he will pay $180 per license, and 24 hours will be due at the end of his renewal period. For those holding the Electrical License, half of their hours must be in code.

Those contractors, who did not fulfill their renewal requirements in 2015, will not be eligible for this incentive program. Instead, they will have to renew at the
end of 2016, and take 10 hours of continuing education. If they complete their requirements on time in 2016, their 2017 renewal will allow them to choose ‘1- year’ with 8 hours of continuing education, or ‘3-years’ with 24 hours of continuing education.

Specialty Contracting Company Changes

Senate Bill 78 addresses issues related to specialty contractors, and seeks to eliminate some of the problems facing the industry. One particular concern was
the challenge posed by the “sale” of specialty licenses to unlicensed, unqualified contractors. As many of you are aware, the former law permitted unlicensed tradespeople to perform HVAC, plumbing, electrical, refrigeration, and hydronic work, so long as a licensed contractor “directed and supervised” those activities.
This had the unintended consequence of enabling unscrupulous contractors to claim a supervisory relationship with an unlicensed contractor in exchange for a fee – thereby “selling their license” to the highest bidder. The Board had very few means of catching such abuse, and the end result undermined the OCILB and put Ohioans at risk.

S.B. 78 erases this abuse by removing the “direct and supervise” provision of the law while permitting license sharing between licensed contractors and their employees, thereby ensuring accountability. The bill now requires all tradespeople to be employed, paid by a W2, by the contracting company name on the license. Contractors may also employ tradespeople from a temporary agency but the contractor is accountable for the proper installation of the work.

All licensed contractors SHALL assign a contracting company name to their license. If they are employed by a non-contracting company, their license must be placed in escrow, or provide a copy of three permits obtained for each of the last three years (9 permits total). With this proof, a business entity can be assigned to a license.

The bill also clarifies the penalty powers of the Board, including the ability to require additional continuing education classes, issues fines, or makes criminal referrals.

If you have any questions regarding these two new laws, please feel free to contact Carol Ross, Executive Secretary, OCILB, at 614-644-3495.

Diagnosing a Smart Valve, First Generation

First generation smart valves act as ignition controls and gas valves. There are internal and external safeties that can prevent the valve from working properly. As the valve operates on a 24V signal from a blower control or thermostat, diagnosing these valves is relatively simple.

The smart valve 1 has a 4 pin Molex plug that attaches to the top or side of the control. This 4 pin plug houses 4 wires: a 24V hot, 24V common, electronic fan timer output, and a 24V input from the pressure switch (see diagram below). You should find 24V present between the 24V hot and common at all times when power is applied to the furnace. With a call for heat, the blower control will energize the induced draft blower, which will close the pressure switch. When the normally open pressure switch closes, 24V will be introduced to the pressure switch wire at the valve. This allows the furnace to attempt to light the pilot. After ignition has occurred, the valve will send a 24V signal back out on the EFT terminal to energize the blower motor.

If the pilot light will not light, verify voltage to the pressure switch terminal and the 24V hot terminal. Check for voltage to the igniter with the igniter plug still attached to the valve. If the pilot will light but not the main burners, check flame sense to the valve. Verify that the pilot tubing is securely attached
to the valve.

Jeff Rosenblum
Technical Support
16 Years Industry Experience
Cell (330) 962-2491

Combustion Testing and Why It’s Important

As you may have noticed, there has been a slight chill in the air. Sorry to be the bearer of bad news, but you all know what that means… furnace season is upon us. With the furnaces starting to be put into service, we need to be certain that they are operating safely. The annual tune up just isn’t complete without a combustion test.

Why is it so important to test the combustion of the equipment? Well, without testing, we cannot tell the homeowner that the furnace is safe at the time of service. Above anything, we want to be sure that the homeowner feels comfortable that their equipment is safe and efficient.

There is no better tool than a Combustion Analyzer. With the analyzer, we can test CO, CO2, O2 flue temperature, draft and several others. The tests can also help in diagnosing a bad
heat exchanger. The homeowner trusts us as technicians to be able to detect whether their furnace is functioning correctly and that it is safe to operate, and based on the readings taken with the combustion analyzer, we can do our part in making a homeowner feel safe, which is one of the best things we can do.

Jeff Rosenblum
Technical Support
16 Years Industry Experience
Cell (330) 962-2491

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