Residential Hvac Duct Design Example

How to design a duct system.

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. Larger volumes or higher static pressures should be dealt with on an individual job basis. And i ve seen a lot of times how hvac contractors changed duct designs made by engineers. In this video we ll be learning how to size and design a ductwork for efficiency.

Typical trunk and branch duct systems. Designing a duct system is important but there are a few critical steps that come first. But what i experienced as a new residential hvac service technician. For example if the gauge reads 10 psig then using the above equation the absolute pressure would be 24.

That is really shocking. 10 psig 14 7 psi 24 7 psia. 1 psi equals 27 7 inches of water gauge. You ve got to know how much heating and cooling you need for each room in btu hr.

They don t do it and don t care. Ordinary heating ventilating and air conditioning duct systems read air pressures at 0 4 psi or less often much less. A unfortunately majority of residential hvac contractors have no idea of the heat gain loss calculations and duct design. Hvac for beginners the residential forced air duct system.

This equal friction method of duct sizing should be adequate for normal residential furnace heating and air conditioning applications. This hvac for beginners section begins here with a discussion about forced air duct systems the basics the how and why of duct sizing.