Residential Hvac Duct Design Example

And i ve seen a lot of times how hvac contractors changed duct designs made by engineers.

Residential hvac duct design example.

Number one is the heating and cooling load calculation using a protocol like acca s manual j or the ashrae handbook of fundamentals. A unfortunately majority of residential hvac contractors have no idea of the heat gain loss calculations and duct design. This equal friction method of duct sizing should be adequate for normal residential furnace heating and air conditioning applications. 10 psig 14 7 psi 24 7 psia.

The following duct sizes are based on a fraction drop of 10 inches per 100 feet of lineal duct. Hvac for beginners the residential forced air duct system. 1 psi equals 27 7 inches of water gauge. Ordinary heating ventilating and air conditioning duct systems read air pressures at 0 4 psi or less often much less.

You ve got to know how much heating and cooling you need for each room in btu hr. Ductwork is simply an air delivery system. But what i experienced as a new residential hvac service technician. Larger volumes or higher static pressures should be dealt with on an individual job basis.

Typical trunk and branch duct systems. For example if the gauge reads 10 psig then using the above equation the absolute pressure would be 24. How to design a duct system. In this video we ll be learning how to size and design a ductwork for efficiency.

Designing a duct system is important but there are a few critical steps that come first. This hvac for beginners section begins here with a discussion about forced air duct systems the basics the how and why of duct sizing.