Re: Earth-House

[Jeff Thornton <thornton@xxxxxxxxxxxx>]

I thought I would take a minute and address the confusion on the TESS 
ground models and their availability to TRNSYS users.  We are introducing a 
brand new library for TRNSYS version 16 (due early next year) that includes 
the following models:

1) Slab on Grade (Type 56 mode) : A 3-D Soil Conduction model (finite 
difference approach) that calculates the heat transfer through the slab and 
the resulting thermal impact on the ground beneath/near the slab.  This 
version takes as input the inside surface temperature of the slab (provided 
by Type 56) and the U-value of the slab and calculates the outer slab 
(slab/soil boundary) temperature which is passed back to Type 56 as the 
boundary temperature.  This model allows the user to choose between three 
modes for the surface condition (for the soil/air interface beyond the 
slab); surface temperature provided as an input, surface temperature based 
on long-term average surface temperatures, or surface temperature 
calculated from an energy balance on the soil surface.

2) Slab on Grade (Simple Zone Mode):  This model is very similar to the 
first model, except the user provides the zone temperature (above the 
slab), convection coefficient, incident radiation, surface absorptance and 
surface emittance in order to calculate the surface temperature of the 
slab.  This model is intended to be used with the simpler building zone 
models that calculate the zone temperature and not the wall/floor surface 
temperatures.

3) Basement Model (Type 56 mode): A 3-D Soil Conduction model (finite 
difference approach) that calculates the heat transfer from 5 sides (4 
walls and the floor) of a buried rectangular structure and the resulting 
thermal impact on the ground beneath/near the basement.  This version takes 
as input the inside surface temperatures of the 5 surfaces (provided by 
Type 56) and the U-value of the surfaces and calculates the outer surface 
(surface/soil boundary) temperatures which are passed back to Type 56 as 
the boundary temperatures.  This model allows the user to choose between 
three modes for the surface condition (for the soil/air interface beyond 
the basement); surface temperature provided as an input, surface 
temperature based on long-term average surface temperatures, or surface 
temperature calculated from an energy balance on the soil surface.

4) Basement Model (Simple Zone Mode):  This model is very similar to the 
third model, except the user provides the zone temperature, convection 
coefficients, incident radiation, surface absorptances and surface 
emittances in order to calculate the surface temperature of the 
walls/floor.  This model is intended to be used with the simpler building 
zone models that calculate the zone temperature and not the wall/floor 
surface temperatures.

5) Slab on Grade with Buried Pipes (Type 56 mode); A 3-D Soil Conduction 
model (finite difference approach) that calculates the heat transfer 
through the slab and the resulting thermal impact on the ground 
beneath/near the slab.  The user must define a floor in Type 56 that 
contains all layers above the slab material (carpeting, tile, etc) or 
define a fictitious infinitely thin (negligible resistance) layer.  The 
slab model then takes the temperature at the top of the floor (and the 
floor U-value) and calculates the temperature at the bottom of the floor 
(and on top of the slab) which is passed back to Type 56 as the boundary 
temperature.  This model allows the user to choose between three modes for 
the surface condition (for the soil/air interface beyond the slab); surface 
temperature provided as an input, surface temperature based on long-term 
average surface temperatures, or surface temperature calculated from an 
energy balance on the soil surface.  The model also allows the user to 
simulate systems where a heated or cooled fluid is circulated through the 
slab (and/or soil) via multiple embedded pipes.  The user specifies the 
path(s) through the slab/soil nodes, the fluid inlet conditions, and piping 
parameters and the model calculates the slab temperatures, outlet fluid 
conditions, thermal storage in the soil and slab and all relevant heat 
transfers.

6) Slab on Grade with Buried Pipes (Type 56 mode); This model is very 
similar to the third model, except the user provides the zone temperature, 
convection coefficients, incident radiation, surface absorptances and 
surface emittances in order to calculate the surface temperature of the 
walls/floor.  This model is intended to be used with the simpler building 
zone models that calculate the zone temperature and not the wall/floor 
surface temperatures.

7 and 8)  Like 3 and 4, but with the buried pipes found in models 5 and 6.

9) Buried pipe wrapper:  This model interacts with the Type 31 pipe 
(through the surface temperature) and calculates the heat transfer through 
the use of a 2-D (radial and axial but not circumferential) finite 
difference scheme.

10-13) Buried tank models:  These models are intended to operate with the 
TESS tank models (although they could be used with any tank model) and 
provide calculations for a fluid storage tank that is buried within the 
earth (cylindrical, spherical, rectangular parallelpiped).


The first 6 models are currently available for purchase and include full 
technical documentation, IISiBat proformas, example projects, and source 
code.  The remaining 7 models are currently not available (the models are 
done but the documentation is not) and will be added to the 6 currently 
available models to form the new TESS ground conduction library for TRNSYS 
Version 16 and the 2nd edition of our TESS libraries.

For those interested users (please e-mail or call us) , we can provide a 
list of the parameters/inputs/outputs/derivatives for the selected model 
but will not provide the technical description manual until purchase, as 
this manual contains all the working algorithms and equations used to 
develop the model.

I sincerely hope this e-mail has cleared up some of the confusion and not 
added to it....

Jeff