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Better Solutions Using Mobile Devices

Originally published
Originally published: 9/1/2014

Apps are already providing the latest and greatest technologies your technicians have ever known and app development is slowing down no time soon


The use of mobile devices in field service has provided multiple conveniences for HVACR contractors. Tools as basic as GPS locators pinpointing customer homes and businesses, calendars and reminders that help manage appointments and accessible customer contact information are only the beginning of the list of reasons mobile devices have become essential to serving customers and managing operations.

Over the last five years, thanks largely to the always-on connection to the Internet, smartphone and tablet usage has increased in capability and popularity. Their weight, size and ease of use enable them to serve as valuable extensions of technician knowledge and resources — without bulk or complication. 

Mobile devices have grown in importance to field-service operations for another reason as well. Their widespread adoption has given app developers ample reason to continue providing new options for improving the convenience and efficiency of business operations out in the field. More to the point, mobile devices are revolutionizing how your technicians perform their work. 

Benefits of Using Apps

For your technicians, it’s difficult to downplay the multitude of benefits that stem from mobile-device connectivity. Technical knowledge is broadened, questions are easily answered at customer locations and calculations are accurate. In a short time, these devices become as natural to handle as any other tool on the service vehicles — and actually easier by far than bulky reference manuals and other options from yesteryear.

Because your technicians spend the majority of their time out in the field, they use mobile devices more often than their office-based counterparts. By doing so, they can provide seamless office-based functions, turning their access to data and information into a mobile customer service solution and support center. 

Device apps are quick to start and run. With input via a virtual keyboard, they provide instant results with invoicing, and they generate reports onsite for customers with no need to return to the office first. 

When apps are used in conjunction with cloud databases, information can be backed up immediately and shared with others. Apps also save time in terms of data entry, eliminating double entry. Their speed and convenience increase technician professionalism. 

Four Types of Apps

Knowing all their benefits, the questions remain: Which apps are most useful? If technicians are inexperienced with apps, where should they start? These questions are valid for the simple reason that there are thousands of apps available from which to choose.

Choosing wisely begins by an understanding of the different types of apps that can be used in HVACR field service. Most of these will fall into one of four types: 

  • Calculators — Calculator apps allow technicians to perform complex field-based calculations, such as performing peak HVACR load calculations, determining duct sizes or pressure drops and calculating refrigerant charges.
  • Service management — Service management apps allow technicians to be dispatched to jobs, track service maintenance, as well as create proposals, work orders and invoices.
  • Reference — Reference apps are informational apps that replace bulky, printed PDF manuals and books. As with most online reference, these apps are searchable for easy access to desired information. 
  • Controllers — Controllers are apps that allow users to control physical devices using their mobile device (onsite as well as offsite). 

HVACR Load Calculations

The importance of appropriately calculating peak heating and cooling loads is obviously of utmost importance to HVACR system design. The right load calculations are central to equipment selection and duct design and affect construction costs, energy efficiency, comfort, indoor air quality and building durability, among other essentials to the residential or commercial building operation. Mistakes here can be extremely costly to the customer and ultimately to the contractor. As an alternative, apps increase accuracy and reduce the risks associated with load calculation error.

HVACR load calculators allow technicians to enter information about a house or building and calculate the peak cooling and heating requirements. In the past, the work was much slower. Technicians performed these rigorous calculations either by rule-of-thumb (not professional) or back at the office. This took a lot more time. Now, by entering the data and performing all calculations in the field, the technician is able to immediately get a result and recommend a system to a client. 

The formulas within the apps do the calculations, and this information is used to size the HVACR equipment for a building. Technicians have confidence in the system solutions they recommend. Not only that, the next step is assured as well. Reports produced from this software are required to be submitted to a city or state inspector’s office so the tech can receive a permit. This validation process keeps the project moving forward. 

Today, many states and municipalities require Manual-J based HVACR load calculations to be performed prior to pulling a permit to do retrofit work. Before apps were available, HVACR technicians had to manually write down the information about a home or building, return to the office, and perform the load calculations on a desktop computer. Today, using approved Manual-J apps, technicians can do all of this in the field, email the required report and pick up the permit the same day as opposed to waiting days or even a week.

These calculations and all the other formulas that a technician would need to use — including total air flow calculations, air pressure drop calculations, Fahrenheit/Celsius conversions, infiltration and ventilation loads, duct sizing, pipe sizing and psychrometrics — are easily accessible and can be run accurately and quickly. 

Service Management Apps

Service management apps include a wide range of types of apps such as invoicing, estimating, maintenance recording, dispatching, and more. Service management apps are perfect for field-based service people such as HVACR technicians, since these people are often in the field more than they are in the office. Their use of mobile devices to perform their daily work provides them with many of the same efficiencies as any office-based worker. 

Service personnel often rely upon three main functions:

  1. Dispatching, so they know where to go
  2. Project and equipment information, so they know what to fix and can record what they did
  3. Estimating and invoicing, so they can convey to the client how much it will cost and how to pay

Dispatching is tailor-made for mobile use. A dispatcher at the office can use a backend software system to assign jobs to technicians while the technician can open their dispatching software client on their mobile device and instantly see which jobs are to be done and approximate times for each during the day. 

There is no need for technicians to call in to the dispatcher or even drive to the central office each day. Instead, they automatically receive the scheduling information on their device. As an added benefit, mobile devices have GPS so that with the input of the address, they can direct technicians to the location that is being serviced as well as optimize the route if there is flexibility in the order of the service calls. In some cities, traffic information is also available to alert technicians of any delays on roadways. 

Newer types of application are those that allow the technician to view and edit equipment information and share it with other authorized users within the company. This ability provides a good tool for collaborating on recommending systems and addressing issues. 

Technicians can also track all of their equipment location, nameplate and maintenance data along with photos and spec sheets. This information can be synced into the cloud, which allows for backup, administrative management and sharing with other authorized users. These apps are great for communicating with service managers exactly what and when work was completed in real time.

Technicians can customize the app input screens so they can store and view the exact data about building, equipment or maintenance events. These solutions are perfect for performing commissioning and other specialized activities. They allow users to create a specific set of inputs that apply to a company’s workflow then share with other technicians within the company to promote uniformity. 

Technicians can use apps to provide clients with limited access to this information so they can view what was done. Photos can be taken using the mobile device and assigned to the job. Also, specification sheets can be downloaded and viewed. 

Mobile estimating tools are also quite advantageous since they allow the technician to quickly develop an estimate and proposal of how much the job will cost and instantly present a proposal to the homeowner or client and immediately sign off and perform the work. Because tablet devices are so powerful now, they can store lots of data include pricing data on equipment and materials. In addition, some tools tie into online pricing databases for parts.

Reference Apps

Reference apps are a third type of app that allow technicians to, for example, instantly get information about a rooftop unit, how to service it and how to price it. And they’re much easier to handle than bulky reference manuals. 

Technicians need access to many resources as they are out in the field providing service, support and sales. Technician training about products and equipment has always been important, and still is, but now apps shorten the learning time by providing technicians instead with mobile access to the up-to-date, searchable reference material they need when they need it.

While apps can be used on both smartphones and tablets, the upsides and downsides are different at times. Tablets, for example, have larger screens and can be better for viewing drawings and other PDF reference material. Most smartphones with 4G access don’t require Wi-Fi access to use data. However, tablets that don’t come with 4G connectivity can be used to enter data for syncing at a later time. 


Controllers are apps that allow users to control physical devices using their mobile device. For example, many new home thermostats are Wi-Fi-enabled so they can connect to the Internet and be controlled remotely by a mobile device. There are also Wi-Fi-enabled in-home security cameras that can be accessed from mobile devices allowing homeowners to remotely view their home. 

Mobile devices are also “Bluetooth-enabled” meaning they can connect to other measurement devices that also have Bluetooth protocols. For example, a number of Android mobile applications can connect with HVACR pressure-temperature gauges and help calculate the correct superheat or subcool temperature based upon the refrigerant pressure and temperatures. This information is wirelessly communicated from the device to the mobile app. Some apps can also connect with refrigerant scales so your technician knows how much refrigerant is to be released from the tank into the HVACR unit. The scale wirelessly transmits the weight every couple of milliseconds, and the app will sound an alarm when the weight reaches a certain level.

Apps Continue to Improve

Apps are already providing the latest and greatest technologies your technicians have ever known and app development is slowing down no time soon. 

Mobile technology is progressing to a point where users can look into the mobile device camera viewer and view 3D representations of the equipment they are servicing. It almost simulates x-ray vision so the tech can see what is inside the equipment without opening it. This is called augmented reality. Also, high-tech glasses allow users to view information right in front of their eyes about equipment they are servicing.

With thousands of apps already available, HVACR contractors and field service technicians have many options to boost productivity, improve service, increase accuracy and save time — ultimately increasing company profitability. 




Stephen Roth is principal of Carmel Software, a developer of mobile, desktop and web-based software for HVACR and engineering applications. Carmel Software, located in the San Francisco Bay area, has been developing and selling HVACR and other engineering software since 1995. Its software includes mobile, desktop, and web-based software for energy audits, HVAC load calculations, equipment maintenance, duct sizing, pipe sizing, psychrometrics, and much more. For additional information, visit


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