TSI Alnor

TSI Inc. is a global leader and innovator in several precision test and measurement markets including aerosol science, air flow, chemical analysis, indoor air quality, fluid dynamics, biohazard detection, and scrap metal sorting and plastics identification. TSI has been granted over 50 patents and its engineers are dedicated to producing the best, and sometimes only, instruments of their kind. TSI is highly committed to participation in standards committees and societies and manufactures and tests all their products to rigorous standards provided by these various organizations by including an NIST certification with almost all of their products. TSI has a dedicated team worldwide involved with bringing customers superior testing solutions as well as bringing advanced data collection technology to industries that will have a lasting impact on the future of the world.

A vital component of the modern workplace is an HVAC system that makes the building space both comfortable for everyone inside and runs efficiently, making for energy cost savings and savings on potential repair and maintenance costs. To ensure the proper functioning of this system in the building envelope, technicians use the process known as testing, adjusting, and balancing – or TAB for short. It is crucial in the commissioning of an HVAC system that technicians use the correct equipment and receive proper training to execute the tests and do balancing correctly. Training will be up to the contractors performing the work, but we are going to take a look at the wide range of powerful instruments made by TSI Alnor for HVAC commissioning.

The most common and useful tool for TAB work is known as a balometer or air capture hood. You can also call it an air flow hood or air balancing hood and other such names. We'll use them all interchangeably here. Just know it refers to the same set of tools, primarily with TSI products to the TSI EBT731 Balometer Capture Hood. Balometer Alnor (which is now merged with TSI as TSI Alnor) in the 1980s and refers to an air capture hood instrument, but has become synonymous with it. Many people now just say "balometer" to refer to this instrument. Loosely speaking, an air capture hood is used to measure air flow and volume from different diffusers and into return registers to ensure proper function and efficiency of the HVAC system. It is critical that instruments for air capture TAB work be both accurate and well made. TSI is essentially industry standard in this regard. All TSI capture hoods come standard with NIST certifications so you know that the instrument is calibrated to give accurate readings and can prove it to the customer or governing body in charge. TSI air flow hoods are also built to be rugged and durable. Ask your average technician in the TAB field which instrument is best and you'll most likely hear "TSI Alnor EBT731".

Now, as to the process itself, the air balancing hood is one tool in an arsenal that should also include manometers, anemometers, thermometers, and psychrometers. Air balance testing is both a science and an art and will require much knowledge and experience. One reason accuracy is so important, and why we recommend the TSI EBT731 Balometer, is that by the nature of TAB work (which involves the movement of various amounts of heat through the air) readings can vary at a register within seconds. Now, a properly functioning system shouldn't fluctuate too rapidly, but you need to know what you're looking for. If you've purchased a super accurate instrument like the TSI EBT731, your readings will be trustworthy, and you either take an average or stick with the highest reading for safety's sake. Constant testing and patience are the names of the game here. Training is essential in this regard, but so are tools that get the job done right.

To describe the testing procedure very briefly, the system that you're working on will be designed with specific flow and volume standards for maximum efficiency and will be stated by the manufacturer. Adjusting grilles at the register and flow and volume at the diffusers will allow you to balance the airflow of the entire system to meet the standards set down by the designer of the system. Once those standards are met, the system will be running as efficiently as possible. The adjusting part is where the art comes in, as every adjustment will affect the whole system.

The purpose of the air flow hood design is to create a seal around the vent so that the instrument can read a complete "picture" of the volume and flow coming from said vent. An air flow capture hood basically funnels all the air down into the measurement meter at its base. The digital meter will then give readings that you can use to check the performance of the system against the known efficiency standards. While this process is simple in concept, it takes training, experience, and patience to get it done in the field and there are no shortcuts to proper work. That's why you need precision instruments like the TSI air flow balometers we've discussed here. Take our word for it, this is lucrative work if done right, and you will always be happy to have bought top-of-the-line air flow balometers and get trained and educated in the TAB field. The equipment pays for itself very quickly, and you don't want to skimp out and do lousy testing with inferior equipment. Next, we'll take a look specifically at low flow testing environments and the tools for them.

TSI air capture hoods can also be used in residential and light commercial testing and balancing using the TSI Alnor 6200 LoFlo Balometer Capture Hood. Typically, in the past, TAB has been limited to the commercial HVAC field. But there is now a growing demand for airflow efficiency in residential and office applications that is creating a growing market for technicians and contractors who can perform this specialized testing for homeowners and office managers. Now the challenges that technicians face when branching out into light commercial and residential work are two-fold. First, the majority of hoods are made for commercial applications, as we discussed above, simply meaning that they are too big. The second is that the commercial airflow balometers are made to measure much higher volume and flow coming from the AC system.

To address the first issue of size, TSI Alnor has created the 6200 LoFlo Capture Hood with a standard 16" x 16" hood fabric at only 8" tall. This design makes it easy to reach by hand into smaller areas where a large hood cannot be used and also helps to more accurately measure the smaller grilles and diffusers present in the residential building envelope. The TSI 6200 Balometer also comes in two other standard sizes: the TSI 6200D LoFlo Capture Hood which has a wider hood fabric at 2ft x 2ft but still the short height of 8" and the TSI 6200F which features the same smaller opening of 16" x 16" but an extended height of 18". The base testing unit is the same with all of the models, so the variety of hood fabric sizes may also be purchased as separate accessories, making the TSI 6200 a very versatile testing instrument. This feature is practically essential in residential testing, as the register sizes and shapes vary widely in homes, and the technician will need to select the best hood fabric for each peculiar register. This selection is easily made, and the additional hood fabrics are not too costly, especially considering that customers concerned with an efficient home AC and airflow system are a lucrative market for your HVAC services. Also, a neat feature of the TSI 6200 is that for work on very small registers, the base unit can be used without a hood, since it is made with an enclosed circular design.

To address the second common problem faced by the residential and light commercial TAB contractor, TSI Alnor has designed the 6200 models' onboard airflow meter to measure with precise accuracy at low airflow levels, specifically the 10 to 500cfm range that you'll encounter in smaller buildings, including homes. The 6200 capture hood can measure with high accuracy (within 5cfm) at this especially low range.

Couple the design benefits we just discussed with an easy to use physical design at just 6 pounds with the hood, and you've got a laboratory quality, calibrated, precision instrument that is the perfect solution for residential and light commercial TAB technicians.

Next up, we'll take a look at TSI's selection of rotating vane anemometers.

Rotating Vane Anemometers are exciting and highly useful tools for measuring airflow in situations that are not suitable for a flow hood. Let's spend a little time on the background of these devices, and then we'll have a quick look at two of the best models available form TSI Alnor.

Generally speaking, an anemometer is any device that measures airspeed. The name is derived from the Greek word anemos, meaning "wind". So anemometer just means "wind meter." Simple enough! Now, a rotating vane anemometer is very similar in principle and design to a windmill. Airflow impinges on the vane, which is designed in the same shape as a windmill and causes it to rotate. The automatic or digital type of rotating vane meters, like the ones made by TSI and most any other meter that you'd encounter in the modern field, takes an average of different velocities of points across the diameter of the vane. Technically, you don't need to know this part, since the meter will do it automatically. Still, it can be done through manual calculation, and sometimes it's just cool to know and understand the fantastic mathematical feats that our devices can perform. Additionally, since a rotating vane anemometer is mechanical in nature, readings are inherently dampened and thus do not jump around like some digital meters. Less fluctuation allows for more accurate analysis in the field.

Application-wise, rotating vanes are useful in a number of diverse applications. We're primarily focused on the HVAC capabilities here, but it is interesting to note that there are applications in the food industry, laboratory, and even computer cooling racks. You could definitely come up with a lot of ways to contract out your services in a variety of industries using this type of meter. With regard to HVAC, there are a couple of obvious applications. You can use these meters in large open areas, in which you can do an averaging traverse, to get a sense of airflow in the entire space. Alternatively, you can take measurements at each point to find pockets that may be getting too much or too little airflow. Another is in measuring hard-to-reach, small diffusers and registers. This often requires an extension pole, which can be purchased as an accessory. If the vent is larger than a few times the anemometer's diameter, you may need to average using the traverse method. However, many small registers can often be measured directly.

Digital Rotating Vane Anemometers are the most prevalent type of meter in this class on today's job-site. These digital meters have much less friction than analog meters since the rotations are being read by an optical sensor (a Hall effect sensor). Since there is little mechanical friction, these digital meters can be accurate down to rather low airflow speeds like 50ft/min. Now, strictly speaking, what a digital anemometer measures directly is simply air velocity (and also temperature). You will need to enter the vent's or grille's dimensions (or a predefined rectangular or round size) to get an accurate airflow measurement. This technique is simple enough to do with little training, and the meter will do the calculations automatically once dimensions are input. Do note, though, that if the total air stream is smaller than the head of the Rotating Vane, measurements will be inaccurate and that this is an application more suited to the use of a thermo-anemometer.

Two excellent rotating vane anemometers offered by TSI Alnor are the Alnor RVA801 and the. The RVA801 is a simple but powerful all-in-one meter that uses basic push-button operation for accurate velocity readings and flow calculations in the range of 50–6000 ft/min. The rotating vane head is 4 inches in diameter, and it swivels so that you can always see the display screen when taking your measurements. And like almost all TSI Alnor instruments, the RVA801 comes standard with a NIST calibration so that you can be sure you are meeting the requirements of even the toughest regulated jobs.

A slight step up from the RVA801 is the TSI VelociCalc 5725. This unit has the meter separate from the vane, and a cable connects them. There are two significant advantages to picking up this meter. The first is that it is designed with a sweep mode so that you can quickly get an average velocity or volume measurement of a large surface area. There are also many additional sampling features that you can use that we won't cover here. The biggest benefit of getting the TSI 5725 is its ability to do data-logging. It might be obvious, but it's a considerable time and accuracy savings to be able to store all your measurements on the device. Additionally, the meter includes a USB cable and logging software to make it a snap to export all your results to your computer. If you're working in a larger building envelope with lots of measurement points, this capability is simply a must.

There you have it, a quick rundown of Rotating Vane Anemometers.