# Navisizer

> Tool for sizing Navien tankless water heaters and calculating system costs. (iPhone/iPad app by Navien, Inc..)

- Source: https://appshunter.io/ios/app/navisizer/id1327385997 (this page in markdown: same URL + `.md`)
- Developer: [Navien, Inc.](https://appshunter.io/developer/1327385996)
- Category: Productivity
- Price: Free
- Rating: 2.40/5 from 26 App Store ratings · 16 written reviews indexed
- Age rating: 4+
- Requires: iOS 17.2 · 21 MB
- Languages: American English
- Released: 2017-12-26
- Data updated: 2026-06-01
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/navisizer/id1327385997/reviews.md

## What is Navisizer?

NaviSizer is designed to assist with sizing of domestic hot water heating systems with Navien NPE Series tankless water heaters. 

For residential applications, NaviSizer offers system sizing, calculation of operating cost and savings, and provides a comprehensive output to be used as a job spec. 

For commercial applications, NaviSizer uses ASHREA Hunter Curve calculations to size a broad range of applications. Both tankless and tankless with storage solutions are offered along with a comprehensive system spec that can be saved, printed, or emailed.

## Key features

- Residential system sizing
- Operating cost and savings calculation
- Commercial application sizing (ASHRAE Hunter Curve)
- Tankless and tankless with storage solutions
- Comprehensive job specification output
- Save, print, or email system specs

## Recent user reviews (10 of 16)

All indexed reviews: https://appshunter.io/ios/app/navisizer/id1327385997/reviews.md

### 5/5 — Great APP, accurate results

*2022-07-06*

This APP uses real conditions and the Hunter curve to accurately size tankless units for both my residential and commercial projects. I’m quite happy with the results.

### 1/5 — Horrific app

*2022-01-03, version 1.6*

App was clear hastily put together, and has more bugs then a person can count. Don’t waste your time. Just call and bug Navien

### 1/5 — Dysfunctional

*2020-09-09*

Filled out the required fields, but not accepting it.

### 1/5 — Pointless

*2020-08-31, version 1.6*

Clearly a lead generation app that should just be a form on their website.

### 1/5 — Ask a lot and explain nothing

*2020-08-16*

I am a homeowner. I am interested in this product and was hoping this app could connect me to either a licensed retailer or someone qualified to install it. I found neither. When they ask you for different information about your use of water, flow rate, gas bills, etc, they use too many acronyms and don’t explain what they are or how a layman can calculate any of it. They don’t explain the different products either or what the differences are. They need to go back and rethink this app for people who aren’t plumbers or engineers.

### 1/5 — Stupid app.

*2020-07-17*

You can’t even make registration form to work what else you expect to work.

### 2/5 — Canada overlooked?

*2020-05-01, version 1.5*

The tool asks for a postal code or zip code and then proceeds to give a number pad to enter it. Clearly not designed for a postal code which is alphanumeric. Had to put in Washington state to get data and then presumably all the savings estimates are wrong because they assume I am in the states

### 1/5 — Don’t bother

*2020-01-12*

App is terrible. You can’t even enter how many people are in the house it just bugs out. Don’t waste your time.

### 1/5 — Login

*2020-01-09*

Filled out NaviSizer new user form and was blocked by a required fields request. Odd, since all fields were completed. 
I could guess at the sizing of my need. 
It appears the app needs some love. 
Now it requires a Capcha input with no place to input.

### 1/5 — App is terrible

*2020-01-08*

I’m not even sure this is a legit app. Then, who wants to give the name and address of potential customers? I’m sure they would want to approve the sharing of their information.

## Frequently asked questions about Navisizer

### What type of water heaters does Navisizer support?

Navisizer is specifically designed to assist with the sizing of domestic hot water heating systems for Navien NPE Series tankless water heaters. It supports both tankless and tankless with storage solutions.

### Can Navisizer be used for commercial projects?

Yes, Navisizer can be used for commercial applications. It utilizes ASHRAE Hunter Curve calculations to size a broad range of commercial projects, providing a comprehensive system specification.

### What kind of output does Navisizer provide?

Navisizer provides a comprehensive output that can be used as a job specification. This output can be saved, printed, or emailed, making it easy to share project details.

### How does Navisizer help with cost analysis?

For residential applications, Navisizer offers calculations for operating costs and potential savings. This helps users understand the financial implications of different system configurations.

### What is the update frequency for Navisizer?

Navisizer was last updated on April 29, 2024, indicating recent development and maintenance. The current version is 3.

### What devices is Navisizer available on?

Navisizer is available for both iPhone and iPad devices, making it accessible to a wide range of users in the field.

### Does Navisizer have ads?

No, Navisizer does not contain advertisements, providing an uninterrupted user experience.

### What is the user sentiment for Navisizer based on ratings?

Navisizer has an average rating of 2.4 stars from 26 ratings. This suggests that while the app offers useful functionality, there may be areas for improvement in user satisfaction.

## Version history (last 5 releases)

### 3 — 2024-04-29

Added the NHW-AI and NHW-AE units

### 2 — 2022-07-07

We updated all the model lines and improved functionality.

### 1.6 — 2020-07-16

Update to Postal Codes

### 1.5 — 2020-03-11

Updates to how we handle location data and postal codes

### 1.4 — 2018-06-12

Updated Storage Selection

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## More apps by Navien, Inc.

- [Navien](https://appshunter.io/ios/app/navien/id1589126852)

All apps by Navien, Inc.: https://appshunter.io/developer/1327385996

## Related topics

[navien](https://appshunter.io/ios/topics/navien) · [heat2home smokeless ovals review](https://appshunter.io/ios/topics/heat2home-smokeless-ovals-review)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-01.*