Get ahead of the game.
Kick start your HVAC design journey with eleven (11) calculators, five (5) diagrams and three (3) charts
for USD 14.99 only
A chance to be better than others.

Accelerate your design calculations process
Easy-to-use calculators that automate and speed up your repetitive design work.

Get ahead of your friends and colleagues
Gain access to non-beginner design tools that other people don’t have.

Compound your skills and knowledge
Get to know the big picture and compound your skills to stay ahead of the game.
Take your skills to the next level with 11 profound excel calculators.
Many excel calculators are for general purposes but, my excel calculators are tailored for HVAC applications.











A beginner-friendly tool.

Drop down selections and multiple measurement units.
Variations are simplified down to the most relevant few figures in a form of drop down selections to ensure results.


Easy Navigation.
Jumping around calculators has never been so easy. This excel calculator is built with user-experience in mind.

Impressive functionality.

“I am an HVAC professional with 10 years of experience. I have gone through the calculators and I am impressed. I would like to get more knowledge from you.”
Commented by Chandrashekhar from the United Arab Emirates
Buy once, last forever.
All calculators are fully unlocked. So, make it your secret HVAC design tool that you can use for the rest of your HVAC journey.
Fundamentally applicable to everyone.
“I can go back home earlier than my colleagues thanks to those handy calculators.”
– Consulting Engineers
“I’m glad that I found out the pressurization fan was under capacity.”
– Project Engineers
“I bought the calculators for my engineers as a gift. They’re now working independently.”
– Project Managers
“Yes! I don’t have to teach my juniors over and over again. I just give them the calculators.”
– Senior Engineers
“Finally, I don’t have to do design calculations for consultants and project engineers.”
– Sales Engineers
“I pay less for the electricity every month because of excellent HVAC designs.”
– Building Owners

Extra supports
- COP explained with R134a PH diagram
- Typical chilled water system diagram
- Grille sizing CFM quick charts
Great learning doesn’t have to be expensive.
HVAC seminars and courses are expensive. With online technology, great learning no longer expensive. The included COP explanation with PH diagram will change the way you approach the chilled water system.
About the creator.
Yu is the founder and author of aircondlounge. He wrote all the articles on aircondlounge. He combined his more than 7 years of practical HVAC experience and online skills to make the calculators, diagrams and charts in the Design Engineer Starter Pack.

“Many junior engineers don’t get enough guidance from their seniors. Hence, I created the Design Engineer Starter Pack to help kick start their HVAC design journey. I hope that they will eventually design some of the best HVAC systems in the world.”
— Yu Chang Zhen, aircondlounge

Design Engineer Starter Pack
Kick start your HVAC design journey with eleven (11) calculators, five (5) diagrams and three (3) charts
for USD 14.99 only
1% of all proceeds go to fund carbon removal via Stripe.
Technical Specifications
Unit – Primarily SI unit complemented with Imperial unit
Item | Qty | Format | Design Basis |
---|---|---|---|
Chilled Water Pipe Size Calculator | 1 | Excel | Friction Loss < 8 ft; Water Velocity < 10 ft |
Grille Size Calculator | 1 | Excel | Face Velocity; Variable Free Area |
Make-Up Tank Size Calculator | 1 | Excel | Based on Daily Operating Hours |
Pipe Head Loss Calculator | 1 | Excel | Hazen-Williams Equation |
Pressure Rating Calculator | 1 | Excel | Bernoulli’s Equations |
Pressurization Fan Capacity Calculator | 1 | Excel | Minimum 2 Doors or 10% of Total Doors |
Smoke Spill Fan Capacity Calculator | 1 | Excel | Basement Only; Minimum 10 ACH |
Power Cable Size Calculator | 1 | Excel | Current-Carrying Capacity; Voltage Drop |
Cooling Load Calculator | 1 | Excel | ASHRAE GLF and CLTD method |
Duct Size Calculator | 1 | Excel | McQuay Duct Sizer |
Duct Static Pressure Calculator | 1 | Excel | Darcy Friction Loss Equation |
COP Explained with R134a PH Diagrams | 4 | Refrigeration Effect; Power Consumption | |
Grille CFM Charts | 3 | Face Velocity < 500 FPM; Variable Free Area | |
Typical Chilled Water System Diagram | 1 | Southeast Asia Climate |
Frequently Asked Questions
Can I make changes to the calculators?
Yes. The calculators are fully unlocked. You can make any changes as you wish.
Are the calculators applicable to me?
The calculators are created based on methods that are fundamentally applicable to people around the world. They are not dependent on geographic location.
How to use the calculators?
Simply enter your requirement in yellow cells and get the result in blue cells. In addition, you can follow the user guide link in the calculators to learn more.
How to buy?
Click on the buy now button to be directed to SendOwl payment gateway. Enter your name, email address and credit card details to complete the purchase.
When can I get the download link?
Upon payment done, a download link will appear on your screen immediately. In addition, you will also receive an email for payment confirmation including the same download link.
What if I have a problem with the download?
You can contact me by sending an email to [email protected]. I’ll get it sorted out for you.