This is a follow up question to one that I asked here.

I am measuring the total pressure at the registers (all registers are open) with the BMP180 pressure sensor and somehow they don't change very much when the system turns on. Logically, I would expect:

• Static pressure increases since there is more air immediately after the air handler (correct me if I'm wrong on this one)
• Dynamic pressure increases since there is air flowing through the register

So, I can see two reasons why I'm not seeing a difference:

1. The increase in pressure is so small that it is no different from noise at the pressure sensor (3 - 6 Pa noise)
2. There is some fundamental flaw in the pressure sensor such that it is not able to detect the pressure changes in the ducts

Does anyone have a better explanation why there is no change in pressure at the registers?

This is a follow up question to one that I asked here.

I am measuring the total pressure at the registers (all registers are open) with the BMP180 pressure sensor and somehow they don't change very much when the system turns on. Logically, I would expect:

• Static pressure increases since there is more air immediately after the air handler (correct me if I'm wrong on this one)
• Dynamic pressure increases since there is air flowing through the register

So, I can see two reasons why I'm not seeing a difference:

1. The increase in pressure is so small that it is no different from noise at the pressure sensor (3 - 6 Pa noise)
2. There is some fundamental flaw in the pressure sensor such that it is not able to detect the pressure changes in the ducts

Does anyone have a better explanation why there is no change in pressure at the registers?