Tuesday, November 13, 2012

Home Performance Contractor Dreams

The Three Laws of Home Performance Contractor

First Law 
A performance contractor must do no harm through action or in action.

Second Law 
A performance contractor must follow the principles of building science unless they are in conflict with the first law

Third Law 
A performance contractor must protect their own interest unless that protection conflicts with the first and second law.

Oth law

A performance contractor may not harm by inaction or allow harm by action.

For those of you whom have not read the Robot series by Isaac Asimov will not appreciate my total and complete rip off of the three laws of robotics. The Oth Law came later and you cannot promote 3 laws through three books and then simply change to four laws in your next literary endeavor hence the zeroth law which proceeds all but really came later.  By the way the title is also a rip off. I would suggest reading those books rather than my blog  as they are actually interesting

As I have noticed over the years we seem to put many rules on ourselves in performance contracting. As we embark out on our journey to make a difference I wonder if we are hindered by our own rules?

When does do no harm paralyze us to the point where we do nothing at all? Are we so afraid of the results of our actions that we are relegated to inaction?  Have we become robotic that we are unable to break from the confines of our own rules to do the right thing? Have we set the bar so high that we simply gaze up at it and never get over it?

So some of you might wonder how dare I ask these questions and who the hell is Isaac Asimov and those that do know who Isaac is you are probably musing that this guy is no  Asimov but he is somewhat of an….

So I read that we need to rid the world of all atmospheric drafting combustion appliances and cannot recommend anything other than sealed combustion furnaces. That all energy models lie and therefore we are liars. That we cannot seal duct systems because we might reduce the airflow across the coil and cause the system freeze and fail.

This causes me to  ponder at what the hell can we do?

While it appears often the goal is to separate ourselves from the Construction Industry but somehow fail to recognize that that is the industry we are in. I have seen and heard from many how we need strict quality control to promote the integrity of the industry with qualified findings and third party verification. While it might just be that we talk too much and don’t do enough.

Has this fear of never doing anything wrong left us paralyzed and stuck in a quagmire of good intentions?

Tell me if this model would work in the plumbing industry. Customer has a clogged drain. Drain unclogging analyst is called and agrees your drain is clogged. He has 3 immediate solutions
1)      Use a plunger
2)      Use a toilet auger
3)      Use a snake

He then devises three long term solutions
1)      Camera the line for anomalies
2)      Provide a plan for a deep sewer retrofit
3)      Install a zone multi zone flushing kit on your current sewer system
He then further explains there is a rebate for the multi zone flushes kit and after its installation a third party verifier will show up and confirm the multi zone flush kit is installed and working properly

Customer explains he really only wants the line cleared and questions whether you do it or not. You explain that you are a third party drain analyst with certifications as a HIMS Rater which is an acronym for Hydro Industrial Mensa of Sewers  and  if you want to participate in the MZFK or multi zone flush kit program you have to call an MFPC or certified multi flush performance contractor that is participating in WGA or water go away program.  And furthermore in order to qualify for the rebate he needs to have his lines cameraed and receive a bid for a deep sewer retrofit performed by a  SUA or Systems Unclogging Analyst use the flusherator 2000 WGA approved program and that you happen to be both a HIMS and a SUA professional and have the Flusherator 2000 program

Customer again ask if you can unclog the drain You shake your head and smile of course not as a HIMS and SUA you only advise but that you will be extremely happy after the report which tell more about s@#t that you ever imagined! You will upload the information to the WGA database and they will get back to you as to whether or not you have the certification and then you can hire a MFPC. You further explain that this system really does make sense after all as you would certainly not want a MZFK by anybody other than a WGA approved MFPC

I think our system might be a tad bit  over complicated and has way too many acronyms. Our quest for perfection has left us with complicated checks and balances that have left us at the end of the day ineffective. If we are to drive forward in the industry we need to find a balance of what we want to perform and simply the process and get things done.

It might be that this over complication confuses customers and ultimately drives work away from our industry. I think we need to recognize that in any industry there will be good guys and bad guys and we should just focus on getting customers and doing good work.

I think Paul Raymer sums it up best when he asks “How hard can it be? I will now quote the most dynamic quote in modern American history that can save us all.
“Git er done”


Saturday, November 3, 2012

Zoned HVAC Systems and Design Issues

HVAC systems are designed to condition air in our homes. The bigger the home, the bigger the system to condition that air. As system size increases so does the amount of air it moves and energy it uses. There are new modern systems that have modulating speed that the flow increases and decreases depending on load needs. The fan can increase and decrease in speed which is balanced between the return and supply air of the system.

Traditional systems that are installed in many homes have a on or off method.  The thermostat calls for conditioned air and turns on reaches the temature setting of the thermostat and turns off.
In each case modulating and traditional system air flow is key for the units operation. Without proper airflow systems do not work as designed.

While zoned systems can be an excellent choice for energy savings and comfort in homes the design and implementation must be correct for the system to work properly.   The idea is that the system can separate zones and only condition the area that you are in.  As we turn on the thermostat in one zone the unit turns on. We are now only pay to condition the space we are occupying saving energy and money with only one HVAC unit. This saves upfront and operation costs.

When using traditional HVAC Systems for a zoned system, the ducting is inadequate to handle the air flow when only one zone is being called for.  The air being produced now in the unit is causing static pressure to rise in the system.  The air must go somewhere so either the system chokes down because the static pressure air is resisting the air flow out and will compensate by resisting airflow in causing a host of problems or the pressure or flow must be diverted to maintain cfm flow.

There are two strategies for handling this problem in a traditional HVAC systems. One would be to “dump” the supply air into the space of the home into a large area such as a hallway.  The other method will use a “by pass duct” which as the pressure rises the air is diverted to the return via this by pass duct. Here are some reasons that make the bypass duct a poor design in any system

1)      By diverting the conditioned air during the cooling season we are pushing colder air into the return. This makes the coil colder and reduces the efficiency of the system. Our cooling capacity is then significantly reduced
2)      Our air conditioner and heaters are designed to have the supply and return separate. By combining the two in this manner air can be detrimental to proper flow. Air can be described as being lazy; it will follow the path of least resistance. Even if all four zones are open having a large hole to escape into right at the point of the most pressure the unit itself, some air will cheat to the bypass duct and system will not have proper return flow.
3)      By having the colder conditioned air directly to the return end of the system and restricting flow from the supply part of the system we now have risk of the system freezing up or icing up.  

The bypass duct systems have two methods for controlling the bypass air. The dampener for the bypass duct is controlled by either static pressure and or mechanical.

The mechanical is always preferred as it acts in concert with the supply dampeners and as the system calls for more or less air it adjusts it position mechanically. This can be tested and the flow balanced and set.

A static pressure controlled dampener  also known as a barometric controlled dampener works by pressure and balance. As the static pressure builds the dampener opens to the return for the bypass air such as during the operation of one zone.  As the system calls for more air the static pressure drops and so does the dampener closing the air to the return. The dampener needs to be completely level and the weight on the dampener must be adjusted perfectly and tested to ensure that the flow is correct. For proper operation the perfect level and balance must be maintained.

While used as a solution the barometric controlled dampener is difficult to install correctly and for system operation must really be perfect.

I would never recommend a system that combines the return air to the supply air for many reasons that are listed above and if one were installed I would recommend only a mechanical dampener be installed

In conclusion zoned systems can work quite well.  Zoning systems that are designed from the beginning are state of the art and can increase comfort and reduce cost by conditioning only the space you occupy. There are some key components that are lacking in this system to make it state of the art.

1)      A modulating system that can increase and decrease flow depending on demand.
2)      Mechanically dampened supply and return to isolate zones
3)      Separate returns for each zone for proper temperature control