HVAC Load Plus vs testo Smart
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
HVAC Load Plus
Perform detailed heating and cooling load calculations for buildings in the field using your iPhone. Access a vast weather database and construction data to generate comprehensive reports that can be emailed or exported to spreadsheets.
- Detailed heating and cooling load calculations
- 1000+ city weather database
- Extensive construction type data
- Unlimited project creation and storage
- Comprehensive load breakdown reports
- Emailable HTML reports with spreadsheet attachments
- Company information display on reports
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The HVAC Load+ iPhone app allows you to perform detailed heating and cooling block loads for small commercial and residential buildings out in the field by taking advantage of the simplicity and power of the iPhone. It performs heating and cooling block load calculations based upon industry standard calculation methods. The following is just a small sample of the features included in this app: 1. Includes a 1000+ world-wide city weather database 2. Includes data for 100s of construction types for walls, roofs, floors, doors, windows, skylights, ceilings, and more 3. Allows you to create and store an unlimited number of projects. You can also copy existing projects to new projects for easy reuse of data 4. Allows you to specify an unlimited # of opaque types (ie – doors, walls, roofs, floors, ceilings), window types, and skylight types for each building 5. Allows you to view comprehensive cooling and heating load breakdown reports including breakdown by opaque load, window load, skylight load, infiltration load, ventilation load and internal load contributions 6. Opaque inputs include opaque type, opaque construction number, dimensions, and opening areas 7. Window inputs include window type, internal and external shading type, overhang dimensions, window area, and more.. 8. Skylight inputs include skylight type, dimensions, orientation, and more.. 9. Additional input types include # of people, # of bedrooms, ventilation airflow, and more.. 10. Includes the ability to display a comprehensive HTML report that you can email to yourself or others, and it also includes a spreadsheet attachment that you can open in Excel to further massage data on your desktop 11. Includes ability to input your company information to display on the emailed report 12. Includes ability to display units in either English (IP) or Metric (SI). 13. Equipment location services It also includes 2 bonus modules: 1. The "HVAC Equipment Locator" has the same functionality as our stand-alone Locator app. It allows you to input information about all of your HVAC equipment, upload it to a remote web server (at www.carmelsoft.com/EL), and SAFELY share information about it with other technicians within your company. The equipment's GPS coordinates become its globally unique identifier, allowing you to input and retrieve information about it just by standing next to it. 2. The “HVAC Quick Load” module allows you to quickly perform rule-of-thumb heating and cooling load calcs based upon just inputting the building type, square area, and # of people. Please see the description located under the stand-alone "HVAC Quick Load" app for more details about it. The benefits of using this app are: 1. Great for use out in the field. Quickly size heating and cooling equipment, show the client, then email the results back to your office for further analysis. 2. Show off your advanced on-screen reports to clients convincing them you are using cutting-edge technology 3. Save time by inputting information in the field and then returning to your office to perform more in-depth analysis This app was designed by Carmel Software Corporation, a 20-year old software design firm specializing in engineering analysis software applications geared toward engineers, architects, technicians, and home owners. In fact, our software powers the analysis capabilities of major Autodesk software tools such as Revit (The makers of AutoCAD). We will continue to update this app based upon user feedback. Please email us at info@carmelsoft.com for any comments. We also offer training and tutorial videos at: www.carmelsoft.com/HVACLoadPlus.
testo Smart
This app supports measurements for refrigeration, HVAC, and heating systems. It also aids in food safety, frying oil quality, and indoor climate monitoring. Quickly interpret data, create digital reports with photos, and send them via email.
- All-in-one system measurements
- Graphical display of measured values
- Digital PDF/CSV measurement reports
- Email report sharing
- Leak test analysis
- Automatic refrigerant charging
- Indoor air quality monitoring
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- All in one: The testo Smart App supports you with measurements on refrigeration, air conditioning, and heating systems, as well as in ensuring the safety and quality of food and frying oil, and in monitoring indoor climate and storage conditions. - Fast: Graphically descriptive display of measured values, e.g. as a table, for quick interpretation of results. - Efficient: Create digital measurement reports including. photos as PDF/ CSV files on site and send them via e-mail. The testo Smart App is compatible with the following Bluetooth®-enabled measuring instruments from Testo: - Thermal imager testo 860i for smartphones - All Testo Smart Probes - Digital manifolds testo 550s/557s/558s/550i/570s and testo 550/557 - Digital refrigerant scale testo 560i - Vacuum pump testo 565i - Flue gas analyzer testo 300/310 II/310 II EN - Vacuum gauge testo 552 - Clamp meter testo 770-3 - Volume flow hood testo 420 - Compact HVAC measuring instruments - Frying oil tester testo 270 BT - Temperature meter testo 110 Food - Dual purpose IR and penetration thermometer testo 104-IR BT - Data loggers 174 T BT & 174 H BT - Online data loggers testo 160, testo 162 & testo 164 GW Applications with the testo Smart App Refrigeration systems, air conditioning systems and heat pumps, heating systems, indoor air quality: - Leak test: Recording and analysis of the pressure drop curve. - Superheat and subcooling: Automatic determination of condensation and evaporation temperature and calculation of superheat / subcooling. - Target superheat: Automatic calculation of target superheat - Automatic refrigerant charging by weight, by superheat, by subcooling, and by target superheat - Vacuum measurement: Graphical progress display of the measurement with indication of start and differential value Indoor climate monitoring: - Indoor air quality: automatic calculation of the dew point and wet-bulb temperature - Temperature, humidity, lux, UV, pressure, CO2: the right data logger for every application – from a single solution to an online monitoring system" Ventilation systems: - Volume flow: After the intuitive input of the duct cross-section, the app calculates the volume flow fully automatically. - Diffuser measurements: simple parameterisation of the diffuser (dimensions and geometry), comparison of the volume flows of several diffusers when setting up a ventilation system, continuous and multi-point average calculation. Heating systems: - Flue gas measurement: Second screen function in combination with testo 300 - Measurement of gas flow and static gas pressure: Also possible parallel to the flue gas measurement (delta P) - Measurement of flow and return temperatures (delta T) Thermography: - Determining Delta T on heating, refrigeration/air conditioning, and industrial systems - Detecting hot/cold spots - Assessing the risk of mold Food safety: Temperature Control Points (CP/CCP): - Seamless documentation of measured values to fulfill HACCP specifications - Individually definable limit values and measurement comments within the App for each measurement point - Reporting and data export for regulatory requirements and internal quality assurance Frying oil quality: - Seamless documentation of measured values as well as calibration and adjustment of the measurement instrument - Individually definable limit values and measurement comments within the App for each measurement point - Reporting and data export for regulatory requirements and internal quality assurance --------------------------------------------------------- Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://www.testo.com/en/company/privacy-policy-app
Screenshots
Verdict
The clearest difference is price: testo Smart at Free against HVAC Load Plus's $24.99. testo Smart also leads on update cadence (every 2 months vs every 9 months) and ratings volume (170 vs 5). HVAC Load Plus's advantage is review sentiment (60% vs 16%) and iOS requirement (13.0 vs 18.0). On rating, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
testo Smart is free to download; HVAC Load Plus costs $24.99 up front. HVAC Load Plus sells 1 one-off in-app purchase and testo Smart sells 5 in-app purchases, starting at $6.99 per month. Whichever you choose, the download price is not the number that matters.
On the App Store both sit at effectively the same score — 2.8 for HVAC Load Plus against 2.7 for testo Smart. That said, the two scores are not equally well evidenced: testo Smart has 170 ratings behind it against 5, so its average is the more settled of the two. Written reviews are what separate them: 60% of HVAC Load Plus's written reviews are positive against 16% of testo Smart's.
HVAC Load Plus ships an update every 9 months, testo Smart every 2 months. The most recent releases landed on November 1, 2026 and November 4, 2026 respectively.
| Parameter | HVAC Load Plus | testo Smart |
|---|---|---|
| Price | $24.99 | Free — better |
| Rating | 2.8 (5 ratings) — better | 2.7 (170 ratings) |
| Positive reviews | 60.0% of reviews — better | 16.3% of reviews |
| Number of ratings | 5 | 170 — better |
| Update frequency | Every 9 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Paid | Free with in-app purchases — better |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 13.0 — better | 18.0 |
| Further details — not scored | ||
| Size | 18 MB | 195 MB |
| Age rating | +4 | 4+ |
| Developer | Carmel Software Corporation | Testo SE & Co. KGaA |
Customer experience
HVAC Load Plus
testo Smart
Bugs and requests
HVAC Load Plus
Not enough reviews yet to summarise bugs or requests.
testo Smart
Reported bugs
5 issues- App won't connect to devices
- Compatibility issues with newer iOS versions
- Frequent crashes and freezes
- Inability to save favorite refrigerants
- Measurement data not displaying properly
Requested features
7 requests- Add option to toggle Bluetooth discovery
- Improve Bluetooth range
- Add ability to customize colors and graphs
- Improve data export functionality
- Add option to name sensors
Show 2 moreShow fewer
- Improve multi-probe support
- Integrate more features from physical devices
In-app purchases
HVAC Load Plus
- HVAC Equipment Locator$9.99
testo Smart
- Multi-site measurement7 Days trial$6.991 Month
- Air balancing7 Days trial$9.991 Month
- Multi-site measurement$69.901 Year
Show 1 moreShow fewer
- Air balancing$99.901 Year
- Logging digital manifold$44.99
Questions
Is HVAC Load Plus free?
Is testo Smart free?
Which has better reviews, HVAC Load Plus or testo Smart?
Do HVAC Load Plus or testo Smart have ads?
Which is updated more often, HVAC Load Plus or testo Smart?
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