# Ventilation effect

1. Feb 15, 2006

### TSN79

I want to calculate how much effect in Watts a ventilation system brings into a room. Will it be correct to use the following equation for this:

$$\dot Q = \dot V \cdot 0,335 \cdot \left( {T_A - T_O } \right)$$

where 0,335 is actually the Cp of air derived from ${{1005} \over {3600}} \cdot 1,2$
TA is the temperature the air enters the room with, and TO is the outside temp.

If the air enters the room with a lower temp than the room, how can the energy needed to heat up this air to room temp be taken into account?

2. Feb 16, 2006

### minger

I would think that should work, however, check your units. On the left you have watts, or J/s, on the right you have (m^3/s)(J/kgK)(K) giving you...well not what your looking for. I'm pretty sure you need to change your volume flow to mass flow.