## 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

## Flex And Round Duct Sizing Charts CFM (4,6,8,10,12-Inch 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

## kW To BTU Calculator: Convert kW To BTU (+ Chart)

In HVAC, heating and cooling capacity is sometimes expressed in kilowatts (kW). To properly understand how powerful an air conditioner or a furnace is, we need to convert kW to BTU (BTU per hour, to be precise). To simply convert kW to BTU, you can use this handy calculator:   Basically, you just input the … Read more

## SEER Rating Calculator: Easy-To-Use AC Running Costs Estimate

SEER rating should be the No. 1 factor when choosing an air conditioner. Higher SEER rated AC units can save you \$1,000s over the next 10-20 years in electricity bill savings. To see exactly much you can save by choosing an air conditioner with a higher SEER (above the federally mandated minimum of 14 SEER), … Read more

## Meter Cube Per Hour To CFM Conversion (m3/hr to cfm)

Airflow is either measured in meter cube per hour or CFM. CFM or cubic feet per minute is usually the more useful metric. However, specification sheets of some devices like air purifiers may include meter cube per hour (m3/hr) but not CFM. That’s why it’s useful to convert meter cube per hour to CFM. How … 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

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

Watt-hours and amp-hours are both units for electric charge. 1 watt-hour is defined as 1 watt of power expended for 1 hour. 1 amp hour is defined as 1 amp of current expended for 1 hour. How do you convert watt-hours to amp-hours? It is possible to convert watt-hours to amp-hours using the following formula: … Read more

## Watts To Volts Converter (W to V): Calculator + Conversion Chart

If we know the amperage (A), we can easily convert watts to volts. For the W to V conversion, we can use the formula for electric power: P (W) = I (A) * V (V) To calculate volts from watts, we need to rearrange this formula by expressing voltage like this: Volt = Watts / … 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