FAQ (RSS)
Cooling
What should I expect from my heating/cooling contractor?
How will air balancing solve my problem of rooms with different temperature?

Heating
What should I expect from my heating/cooling contractor?
How will air balancing solve my problem of rooms with different temperature?

Plumbing
What efficiency standard does a dual use residential water heater need?
What is the average lifetime of a gas water heater?
How is FHR and Therms used to compare the efficiency of water heaters?
Who is responsible for the testing and maintenance of the backflow assembly?
Where should a backflow prevention assembly be located?
Who is required to have a backflow prevention assembly?
How is an assembly approved?
What is a backflow assembly?
My property is served with reclaimed water. Do I need backflow protection?
How can backflow be prevented?
What is backflow?
What is backsiphonage?
What causes backflow?
How can I tell if mold in my house is the bad kind?
Can I get a 100% SER™ Rating?
How do I choose the best electric or gas tankless water heater for my home (2300 sq. ft.)?
Are tankless water heaters more efficient?
What is a hot water recirculating system?

DuctWork
What is a duct system?
How well do my ducts work?
How can ducts affect my system performance?
Other contractors have offered to seal my ducts. Isn’t that the same thing?
Do other contractors address duct systems?
How can I be assured the ducts have been renovated properly?
How can ducts affect my system performance?

Carbon Monoxide
What should I do if my monitor goes off?
Where should I place the NSI monitor?
How many monitors should I have in my home?
Why is the NSI 3000 more expensive than the others?
What about the other “detectors” sold at retailers and home centers?
Why do I need a low-level monitor?

General
Why Choose a Certified Contractor?
What is backpressure?
What can I do to control mold?
What causes mold spores to grow?
Why doesn’t every contractor offer this rating system?
Can mold cause health problems?
How long does it take to measure the SER™ of my system?
Is there a problem with customary equipment efficiency ratings?


What should I expect from my heating/cooling contractor?
An NCI-certified contractor will first ask you questions about the system, what you like and don’t like about it, problem areas, air quality concerns, health issues, etc. He should then perform some preliminary testing to determine the condition of your system, the biggest problem areas, and so forth. This is generally performed using several instruments including a manometer which measures your systems pressure, much like a doctor checks blood pressure. He will typically measure the amount of air coming out of each vent with a special instrument called a “Flow Hood.” Other measurements might include temperature, humidity and carbon monoxide testing.


How will air balancing solve my problem of rooms with different temperature?
The airflow through the system is what carries the heating or cooling. By adjusting the volume of airflow, we adjust the amount of heating or cooling a room needs to become comfortable.

What should I expect from my heating/cooling contractor?
An NCI-certified contractor will first ask you questions about the system, what you like and don’t like about it, problem areas, air quality concerns, health issues, etc. He should then perform some preliminary testing to determine the condition of your system, the biggest problem areas, and so forth. This is generally performed using several instruments including a manometer which measures your systems pressure, much like a doctor checks blood pressure. He will typically measure the amount of air coming out of each vent with a special instrument called a “Flow Hood.” Other measurements might include temperature, humidity and carbon monoxide testing.


How will air balancing solve my problem of rooms with different temperature?
The airflow through the system is what carries the heating or cooling. By adjusting the volume of airflow, we adjust the amount of heating or cooling a room needs to become comfortable.

What efficiency standard does a dual use residential water heater need?
For a dual unit, it must meet the efficiency standard requirements of both applications. Your local building department may have additional requirements for such units.

What is the average lifetime of a gas water heater?
The average lifetime of gas water heater is 9 years. The range is 5-14 years.

How is FHR and Therms used to compare the efficiency of water heaters?
The first hour rating (FHR) tells you the number of gallons per hour of hot water. Therms relate to the gas consumption of water heater. When you are shopping for hot water heater, compare the energy factor on the energy guide label. FHR and Therms are not sufficient to calculate the energy factor. Also remember to compare water heaters of equal capacity and FHR.


Who is responsible for the testing and maintenance of the backflow assembly?
It is the sole responsibility of the customer to ensure that the assembly is in satisfactory operating condition at all times. Annual testing is required to stay in compliance. The customer must contact a recognized or licensed Backflow Assembly Tester to perform the test. If any repair work or maintenance is performed on the assembly, a recognized Tester must retest the assembly immediately and submit the test results to the Backflow Prevention Section.

Where should a backflow prevention assembly be located?
Generally, the backflow prevention assembly must be located as close as possible to the water service connection, but must remain on private property. Contact a licensed professional for information on variances.

Who is required to have a backflow prevention assembly?
Federal and State law require that water suppliers protect their water systems from contamination. State regulations exempt single family residences used solely for residential purposes from assembly requirements. However, residences used for other purposes, as well as commercial and industrial customers, may be required to install and maintain backflow prevention assemblies. When a determination is made by health official that the potable water system may be subject to contamination through backflow, a backflow prevention assembly will be required. Tempe Environmental Division makes these decisions on a case by case basis.

How is an assembly approved?
An approved backflow prevention assembly has gone through an approval process at the Foundation for Hydraulic Research and Cross Connection Control at the University of Southern California. This is a two step process consisting of laboraton/tests and a twelve month field test. Only assemblies completing the entire testing procedure are recognized by Tempe Water as approved backflow prevention assemblies.

What is a backflow assembly?
A backflow preventer is an approved, testable assembly which uses valves, in different configurations, to prevent polluted or contaminated water from reversing direction and flowing backward.

My property is served with reclaimed water. Do I need backflow protection?
Yes. Customers receiving reclaimed water must install a Reduced Pressure Assembly (RPA) backflow preventer on all potable water connections, including fire services.

How can backflow be prevented?
Tempe recognizes four methods of backflow prevention:
  • Air Gap
  • Double Check Valve Assembly
  • Reduced Pressure Principal Assembly 
  • Pressure Vacuum Breaker Assembly
     
The Environmental Division will determine which type of protection is required based on the degree of hazard that the property represents to the potable water supply.

What is backflow?
The water distribution system is designed to keep the water flowing from the distribution system to you the customer. However, when hydraulic conditions within the system deviate from the "normal" conditions, water flow can be reversed. When this backflow happens, contaminated water can enter the distribution system.

What is backsiphonage?
When there is a sudden reduction in the water pressure in the distribution system, such as during firefighting or when a water main breaks, water flow can be reversed. This can create a suction effect, drawing the non potable substance into the potable water system.

What causes backflow?
Backflow is possible in two situations, backsiphonage and backpressure.

How can I tell if mold in my house is the bad kind?
It takes a laboratory and a 600X microscope to identify a mold species. Your doctor can run a series of tests to determine your reactions to various molds. Mold identification is usually outside the expertise of your air conditioning contractor and should be performed by a qualified specialist.

Can I get a 100% SER™ Rating?
It has been done before, but it’s very difficult. SER Ratings of 90% or better are frequently achieved. What’s more important is that your system’s efficiency can often be increased by 25% to 50%. The biggest benefit is the increase in comfort that you will enjoy every day by actually getting the heating and cooling you’re paying for!

How do I choose the best electric or gas tankless water heater for my home (2300 sq. ft.)?
Sizing of hot water heaters should be based on the number of occupants and their peak hour water demand and not on the size of the house.

Are tankless water heaters more efficient?
Tankless water heater efficiencies are not addressed by the Federal standards. Check the EREC fact sheet for additional resources.

What is a hot water recirculating system?
A "hot water re-circulating" system usually refers to a domestic hot water system that circulates the heated water through the house continuously so as to eliminate or shorten the delay in hot water reaching the faucet after the user turns it on. These systems are most common in multifamily or large building applications where otherwise the delays would be truly unacceptable. They can be real energy hogs if the pipes aren't well insulated.

What is a duct system?
The duct system is a series of conduits that carry the warm and cool air from your air conditioning and heating equipment into your home and then take it back to the equipment. The ducts also control how much air is delivered to each room. The right amount of air will keep the room temperatures where they need to be. If ducts are damaged, improperly installed or the wrong size, they can cut your system’s ability to heat or cool by more than half on hot or cold days, when you need it the most. Your system may or may not be delivering air evenly Your house probably has a web of ducts weaving through your walls

How well do my ducts work?
Ducts move air, and air is invisible. So to determine if your ducts work or not, air properties must be measured. An NCI certified contractor can measure how much air goes to each room and compare it to how much is needed. He will also take other measurements including temperatures and pressures to determine how well your ducts work. Then your contractor will review the results of the test with you.


How can ducts affect my system performance?
Here’s an example: A 30% return duct leak on a hot or cold day can decrease your heating or cooling capacity more than 50% That may sound extreme, but it’s not an uncommon condition.

Other contractors have offered to seal my ducts. Isn’t that the same thing?
No. While duct sealing is definitely done as part of a renovation, sealing by itself cannot address many of the flaws in a duct system. In many cases, just sealing the duct can make the problem worse, as it could choke down airflow causing equipment failure, major comfort problems. In extreme cases, it has caused back-drafting of flues leading to dangerous carbon monoxide problems.

Do other contractors address duct systems?
Unfortunately few have the knowledge or own the tools and instruments to measure the performance of your duct system. If they can’t measure it, they have no idea how to fix it, or even where to begin. They assume that the ducts are just fine.


How can I be assured the ducts have been renovated properly?
Your Contractor should test and adjust the results of his work when the duct renovation has been completed. This step is called air balancing. Up to just 10 years ago, air balancing was performed only on large commercial buildings. Today you can get this same precision adjustment in your home from an NCI trained and certified contractor. He will provide you with a test report showing the final operating condition of your system compared to how it functioned before the repairs were made. In other words, your contractor will prove that you got what you paid for - in writing!

How can ducts affect my system performance?
Here’s an example: A 30% return duct leak on a hot or cold day can decrease your heating or cooling capacity more than 50% That may sound extreme, but it’s not an uncommon condition.

What should I do if my monitor goes off?
Call your CO-Certified contractor at any level below 70 ppm, unless you have symptoms. CO exposure can cause nausea, severe headache, shortness of breath, chest pain, blurred vision, and dizziness. If you experience these symptoms call 911 and leave the house immediately. Above 70ppm, evacuate immediately. If you have symptoms, call 911 from a neighbors house. Call your utility to turn off the equipment until your COCertified contractor can investigate the source of carbon monoxide.

Where should I place the NSI monitor?
CO is lighter than air.Monitors should be mounted at eye level and no lower. They should be placed in an area with good air circulation. If you have only one monitor it should be placed near the master bedroom. Additional locations include your kitchen, nursery, basement, rooms with fireplaces or gas logs, and near your heating system and/or hot water tank.Your professional installation contractor will determine the best location in your home.

How many monitors should I have in my home?
As with smoke detectors, you should have one monitor installed on every level of your home. Even a singlestory home may need two – one at each end.

Why is the NSI 3000 more expensive than the others?
Accurate, low-level CO detection requires more expensive components & quality control. The NSI 3000 CO monitor uses the same technology and sensors as in professional-grade CO analyzers used by contractors, fire departments, and utilities.And NSI’s unique Continuous Scan™ mode lets you know the monitor is operational 24/7!

What about the other “detectors” sold at retailers and home centers?
Store-bought detectors don’t alarm until unsafe levels of 70 ppm or higher are present at the unit for 3-1/2 hours! By then it may be too late. Plug-in models don’t always allow for proper placement and don’t work during power outages. The NSI 3000 is battery powered for 24/7 protection.

Why do I need a low-level monitor?
The NSI low level monitor senses CO levels as low as 5 ppm (parts per million). Infants, children, elderly, persons with respiratory or heart ailments are provided little or no rotection from deadly CO with standard alarms. Longterm exposure to Low-level CO above 15 ppm can cause illness and even permanent disabilities.

Why Choose a Certified Contractor?
Signature:26af577b7b721f3126f36118cf361c82eb0ea6bc184f9bc4f6998ff8d1f7fdbdWhy chose a NCI certified contractor?

For the same reasons most of us choose:
  • A certified public accountant to do our taxes
  • A certified realtor to sell our houses
  • An AMA-certified doctor to examine and treat us
  • A bar-certified lawyer to represent us in court
  • In all of these professions, the designations come to people who have studied, tested and achieved a level of competence that resulted in receiving a professional designation.
An NCI certified contractor in air diagnostics and balancing, or certified in carbon monoxide and combustion is no different. NCI certified contractors have attended classes, used specialized equipment and are constantly up-to-date on the latest diagnostic and repair techniques in these fields.

An NCI certified technician has passed a recognized testing process which validates his or her understanding of the technology and procedures used in this field. In addition NCI monitors their certified contractors and requires recertification every 2 years.

You might find a qualified uncertified contractor who could diagnose your comfort problem. You might also find someone who knows a lot about law who could represent you in court. The question is; does it make sense?

You can count on us to do your diagnostic and repair work efficiently because our technicians are NCI (National Comfort Institute) certified.


What is backpressure?
Backpressure is created when pressure in a nonpotable system, such as in a recirculating system containing soap, acid, or antifreeze, exceeds that in the potable system that provides make up water to the system. This can force the potable water to reverse its direction of flow through the cross connection. Nonpotable substances can then enter the potable water system.

What can I do to control mold?
Typical household cleaning contains mold growth in visible areas and normal household cleaning products can clean susceptible surfaces including the shower and tub areas, or around sinks. Use exhaust fans after showering. Repair any plumbing or roof leaks. Always clean up spills or flooding immediately and control moisture in basements.


What causes mold spores to grow?
Mold spores are everywhere. They feed on just about anything organic that can rot. But they exist in a dormant state until one missing ingredient is added: Moisture. At 70% relative humidity, it takes 100 days to establish a culture. At 90% humidity mold can establish a culture in 3 days. Moisture is at the root of all mold problems.

Why doesn’t every contractor offer this rating system?
Unfortunately, there are less than 5000 technicians in the world certified to perform this testing. Most contractors simply aren’t willing to invest in the tools and training to provide this valuable service.

Can mold cause health problems?
Many people are unaffected by mold growth. Other people can become ill when exposed to high levels of mold. Consult your physician if you suspect an intolerance to mold.

How long does it take to measure the SER™ of my system?
It depends on the size of your home. Normally, the testing takes between one and two hours. But stay for the show. The testing is clean, informative and entertaining.

Is there a problem with customary equipment efficiency ratings?
It’s important to understand that equipment ratings are only the potential efficiency of that component of the system under perfect conditions. Think of it as trying to rate your car’s mpg based on just testing the motor by itself. Over half of the system’s efficiency depends on the duct system and the field-installation.