Sensible Cooling Load from Ventilation Air Calculator

Sensible Cooling Load Formula:

\[ Q_s = 1.1 \times VFM \times \Delta T \]

Sensible Cooling Load (W):

1. What is Sensible Cooling Load from Ventilation Air?

Definition: This is the heat that results from temperature differences between outdoor and indoor air due to ventilation.

Purpose: It helps HVAC professionals calculate the cooling capacity needed to maintain comfortable indoor temperatures.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Q_s = 1.1 \times VFM \times \Delta T \]

Where:

\( Q_s \) — Sensible cooling load (Watts)
\( VFM \) — Air ventilation rate (Cubic Feet per Minute)
\( \Delta T \) — Temperature change between outdoor and inside air (°F)
1.1 — Constant combining air density and specific heat

Explanation: The formula calculates the heat energy that must be removed to maintain the desired indoor temperature.

3. Importance of Sensible Cooling Load Calculation

Details: Proper calculation ensures efficient HVAC system sizing, energy savings, and comfortable indoor environments.

4. Using the Calculator

Tips: Enter the air ventilation rate in CFM, temperature difference in °F, and optional tolerance percentage. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the 1.1 constant in the formula?
A: It combines the density of air (0.075 lb/ft³) and specific heat (0.24 BTU/lb-°F), converted to appropriate units.

Q2: How is ventilation rate (CFM) determined?
A: It's based on building codes, occupancy, or air exchange requirements for the space.

Q3: Why include a tolerance percentage?
A: It accounts for measurement uncertainties and provides a safety margin for system design.

Q4: Does this include latent cooling load?
A: No, this calculates only sensible load. Latent load from humidity must be calculated separately.

Q5: What's a typical temperature difference?
A: Depends on climate, but often 20-30°F difference between outdoor and desired indoor temperature.