HAMT FAQ

The Heat and Moisture Transfer (HAMT) model is a computational tool used in engineering to analyze heat and moisture transfer through building envelopes. It considers factors like temperature gradients, material properties, airflow, and vapor pressure differentials, accurately predicting heat and moisture behavior in building components. It helps assess thermal and moisture performance, preventing issues like condensation and mold growth.

Based on robust theoretical foundations, it employs mathematical equations to simulate heat and moisture movements, aiding in material selection and construction techniques for energy-efficient, sustainable buildings. The HAMT model is crucial for optimizing building designs and enhancing occupant comfort by understanding complex interactions between heat and moisture.

What is the Combined Heat and Moisture Transfer (HAMT) Model?

The HAMT Model is a simulation tool integrated into EnergyPlus for analyzing simultaneous heat and moisture transfer through building components. It accounts for dynamic interactions between heat and moisture.

How does HAMT differ from traditional heat transfer models?

Unlike traditional models focusing solely on heat transfer, HAMT considers both heat and moisture transport, making it suitable for hygrothermal analysis.

What types of building components can HAMT model?

HAMT can model various components like walls, roofs, floors, and windows, considering their thermal and moisture properties. On Speckel, HAMT is only available for walls.

What inputs are required for using the HAMT model?

Inputs include:

Material properties: Thermal conductivity, specific heat, moisture diffusivity, sorption isotherms, etc.
Weather data: Outdoor temperature, humidity, solar radiation, wind speed, etc.
Boundary conditions: Indoor temperature, relative humidity, HVAC operation, etc.
Occupant behavior: Ventilation rates, moisture generation, etc.

Speckel manages as many of these inputs as possible, using tested product data fir material properties, sourcing weather data and generating boundary conditions in line with ASHRAE 160 / AIRAH DA07.

How accurate is the HAMT model in predicting transfer?

Accuracy depends on input quality and model calibration. It can provide reliable predictions when calibrated with real-world data.

Can HAMT simulate transient conditions?

Yes, HAMT can simulate dynamic changes in heat and moisture transfer over time.

How does HAMT handle airflow and convective heat transfer?

HAMT considers airflow and convective heat transfer, incorporating factors like air movement and surface conditions.

What are the limitations of using the HAMT model?

Limitations include complexity in defining material properties accurately and computational resources required for detailed simulations.

Can the HAMT model be coupled with other tools?

Yes, HAMT can be integrated with other simulation tools for comprehensive building performance analysis.