General

Location

Address

Address for the Project - used to pick Weather Station.

Latitude

Latitude coordinate: Latitude is a geographic coordinate specifying the north-south position of a point on Earth's surface, measured in degrees (0° to 90°) north or south of the Equator.

Longitude

Longitude coordinate: Longitude is the measurement of distance in degrees, minutes, and seconds east or west of the prime median (0°), which runs through Greenwich, England.

Weather Station

Picks the closest Weather Station to the Address provided in the Nearest tab. Users may search for specific Weather Stations in the All tab.

Elevation

Elevation of the Weather Station A.O.D (Above Ordnance Datum) when the Location is updated but may be overridden to reflect starting level of the Ground Floor - the slab level in respect to A.O.D.

Building Orientation is edited in Floor Plan mode. Select Edit Orientation to go to Floor Plan mode.

Heat Gain

Overview

h2x utilizes EnergyPlus which uses the Heat Balance Method (HBM), which is the ASHRAE-endorsed approach to cooling load calculation.

External Summer Temp

Highest temperature outside based on the Weather Station selected under Location and Design Day Percentile.

External Humidity

Highest humidity outside based on the Weather Station selected under Location and Design Day Percentile.

Design Day Percentile

Select a severity percentile (e.g., 0.4%, 2%, 5%, or 10%).

Ensure you click Refresh to apply changes after inputting/editing the percentile.

h2x runs 24 separate simulations: one for each month of the year, run twice per month under two different ASHRAE design day conditions. The first condition uses the peak dry-bulb temperature for that month (DB => MCWB) and captures the peak sensible cooling load. The second uses the peak wet-bulb temperature (WB => MCDB) and captures the peak latent load. Each simulation models a full 24-hour profile, where the outdoor dry-bulb temperature follows a sinusoidal diurnal curve peaking in the mid-afternoon, and solar radiation follows the ASHRAE Tau 2017 clear-sky model for that month's date and location. EnergyPlus runs warmup days repeating the 24-hour profile until zone temperatures converge before simulating the actual design day.

Relative Humidity (Internal Moisture)

Relative Humidity (Internal Moisture) is a measure of how much water vapor is currently in the air compared to the maximum amount of water vapor the air could possibly hold at that specific temperature.

60% is an industry standard default value, but may be overridden.

Spare Capacity

Add a percentage to allow extra heat gain , providing a buffer for unforeseen conditions (e.g., 10% additional capacity).

Heat Loss

External Winter Temperature

Based on your Project's Address, this defines the Temperature used for heat loss calculations.

Ensure to click Refresh after inputting/editing the address.

Percentile

Select a severity percentile (e.g., 99%, 99.6%, or 100%).

Ensure you click Refresh to apply changes after inputting/editing the percentile.

Base Temperature

This sets the baseline for calculating heating degree days, which affects the energy calculations.

Ground Temperature

The Ground Temperature is used to calculate the heat loss through the bottom floor.

Adjacent Winter Temperature

Set this if there’s a neighboring, non-external space.

When you select a wall to be Party Wall in the design, it will use this temperature rather than the External Temperature.

Spare Capacity

Add a percentage to allow extra heat loss , providing a buffer for unforeseen conditions (e.g., 10% additional capacity).

Thermal Bridging Coefficient

Defines the heat transfer rate through construction parts prone to thermal bridging, like studs.

This number will increase heat loss and heat gain through Materials as a percentage.

Common

Lower Level Room Visibility

Set the Transparency level for rooms below the active level, making it easier to view layouts during design.