Duct Velocity Calculator (Air Velocity = Airflow / Duct Cross-Section)

In HVAC, it’s sometimes useful to calculate the velocity of air in the ducts. All central air conditioners, for example, require ductwork with the specified size of ducts and airflow (measured in CFM). To calculate the speed of air in the ducts, we use a duct velocity calculation (you can find the calculator below). Let’s … Read more

HVAC Duct Sizing Chart (50-3,050 CFM Duct Charts)

Nobody can properly size the ductworks without a duct sizing chart. HVAC duct sizing chart answers one simple question: “What size should my ducts be?” The dimensions of ducts (be it flex, metal, round, or rectangular) determines the airflow (measured in CFM). Example: How many CFM does a 6-inch duct have? A rectangular 6×6-inch duct … Read more

BTU Calculator: How BTU Is Calculated DIY? (With 8.5% Accuracy)

Calculating BTU doesn’t have to be difficult. If you correctly measure the square footage and know the room/home layout, you can calculate the BTU requirements for any air conditioner or heating unit (with under 8.5% accuracy). You can do it yourself using the simple 3-step guide described further on. BTU or British Thermal Unit is … Read more

Amp Hours To Watt Hours Conversion (Ah To Wh): Calculator + Chart

To calculate watts-hours from amp-hours, we need to use the following formula: Watt-hours = Amp-hours * Volts As we can see, amp-hours multiplied by voltage equals watt hours. Using this equation, we can accurately convert watt-hours from amp-hours. You can find the Ah to Wh calculator here:   We have also used the calculator to … Read more

Convert Amps To Watts (A to W): Simple Calculator (+ Conversion Chart)

Amperes (A), volts (V), and watts (W) are the 3 basic electrical units, connecting electrical current, voltage, and power. Every electric device – from air conditioners to washing machines and generators – includes them in their specification sheets.  One of the most common questions here is this: How to convert amps to watts? To convert … Read more