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Hi,

I'm trying to model a representative floor, similar to what is being done here, in question 1305. However, in my model I'm attempting to model radiant floors, without thermal isolation between the slab (like a TABS) concept. Setting to adiabatic isn't ideal, as then the ceiling would not be thermally connected to the radiant floor (I'm experimenting with thermal mass).

In order to capture the heat transfer from the radiant floor to the ceiling of the floor below, I manually surfaced match the two. IE, the boundary condition of the floor is set to the ceiling of the same room.

This seems to create issues. It seems as if the "floor" is no longer recognized as a floor of that zone? I've set the default constructions the same for interior, ground and exterior surfaces.

When I try to run with radiant floor heating, the floors that are "surfaced-matched" to the ceiling are not recognized and I get the critical error:

   ** Severe  ** ZoneHVAC:LowTemperatureRadiant:SurfaceGroup = LOW TEMP RADIANT ELEC SFLOORS does not have any surfaces listed.

As soon as one floor in the zone is set to normal boundary conditions, the simulation runs. Setting to adiabatic seems to work fine too. When I look at the constructions view in SketchUp, everything looks fine.

Any ideas what's causing the issue? I'd upload photos but I don't have enough Karma yet.

Hi,

I'm trying to model a representative floor, similar to what is being done here, in question 1305. However, in my model I'm attempting to model radiant floors, without thermal isolation between the slab (like a TABS) concept. Setting to adiabatic isn't ideal, as then the ceiling would not be thermally connected to the radiant floor (I'm experimenting with thermal mass).

In order to capture the heat transfer from the radiant floor to the ceiling of the floor below, I manually surfaced match the two. IE, the boundary condition of the floor is set to the ceiling of the same room.

This seems to create issues. It seems as if the "floor" is no longer recognized as a floor of that zone? I've set the default constructions the same for interior, ground and exterior surfaces.

When I try to run with radiant floor heating, the floors that are "surfaced-matched" to the ceiling are not recognized and I get the critical error:

   ** Severe  ** ZoneHVAC:LowTemperatureRadiant:SurfaceGroup = LOW TEMP RADIANT ELEC SFLOORS does not have any surfaces listed.

As soon as one floor in the zone is set to normal boundary conditions, the simulation runs. Setting to adiabatic seems to work fine too. When I look at the constructions view in SketchUp, everything looks fine.

Any ideas what's causing the issue? I'd upload photos but I don't have enough Karma yet.

Hi,

I'm trying to model a representative floor, similar to what is being done here, in question 1305. However, in my model I'm attempting to model radiant floors, without thermal isolation between the slab (like a TABS) concept. Setting TABS). Splitting the slab and setting to adiabatic isn't ideal, as then the ceiling would not no longer be thermally connected to the a radiant floor (I'm experimenting with surface, but rather just passive thermal mass). mass.

In order to capture the heat transfer from the radiant floor to the ceiling of the floor below, I tried to manually surfaced match the two. surface-match the floor to the ceiling in each room. IE, the boundary condition of the floor is set to the ceiling of the same room.room.

This seems to create issues. It seems as if the "floor" is no longer recognized as a floor of that zone? then converted to an internal mass object, similar to what happens to walls between spaces in the same thermal zone. I've set the default constructions the same for interior, ground and exterior surfaces. surfaces all to internal source constructions, however once converted this doesn't seem to allow it to function as an internal source surface.

When I try to run with radiant floor heating, the floors that are all the floor in a zone "surfaced-matched" to the ceiling are not recognized and I get the critical error:

   ** Severe  ** ZoneHVAC:LowTemperatureRadiant:SurfaceGroup = LOW TEMP RADIANT ELEC SFLOORS does not have any surfaces listed.

As soon as one floor in the zone is set to a normal boundary condition (Outside) or Adiabatic conditions, the simulation runs. Setting to adiabatic seems to work fine too. When I look at the constructions view in SketchUp, everything looks fine.

Any ideas what's causing the issue? how to simulate a single floor of a TABS building? I'd upload photos but I don't have enough Karma yet.

Hi,

I'm trying to model a representative floor, similar to what is being done here, in question 1305. However, in my model I'm attempting to model radiant floors, without thermal isolation between the slab (like TABS). Splitting the slab and setting to adiabatic isn't ideal, as then the ceiling would no longer be a radiant surface, but rather just passive thermal mass.

In order to capture the heat transfer from the radiant floor to the ceiling of the floor below, I tried to manually surface-match the floor to the ceiling in each room. IE, the boundary condition of the floor is set to the ceiling of the same room.

This seems to create issues. It seems as if the "floor" is then converted to an internal mass object, similar to what happens to walls between spaces in the same thermal zone. I've set the default constructions for interior, ground and exterior surfaces all to internal source constructions, however once converted this doesn't seem to allow it to function as an internal source surface.

When I try to run with all the floor in a zone "surfaced-matched" to the ceiling I get the critical error:

   ** Severe  ** ZoneHVAC:LowTemperatureRadiant:SurfaceGroup = LOW TEMP RADIANT ELEC SFLOORS does not have any surfaces listed.

As soon as one floor in the zone is set to a normal boundary condition (Outside) or Adiabatic conditions, the simulation runs.

Any ideas how to simulate a single floor of a TABS building? I'd upload photos but I don't have enough Karma yet.

Hi,

I'm trying to model a representative floor, similar to what is being done here, in question 1305. However, in my model I'm attempting to model radiant floors, without thermal isolation between the slab (like TABS). Splitting the slab and setting to adiabatic isn't ideal, as then the ceiling would no longer be a radiant surface, but rather just passive thermal mass.

In order to capture the heat transfer from the radiant floor to the ceiling of the floor below, I tried to manually surface-match the floor to the ceiling in each room. IE, the boundary condition of the floor is set to the ceiling of the same room.

This seems to create issues. It seems as if the "floor" is then converted to an internal mass object, similar to what happens to walls between spaces in the same thermal zone. I've set the default constructions for interior, ground and exterior surfaces all to internal source constructions, however once converted this doesn't seem to allow it to function as an internal source surface.

When I try to run with all the floor in a zone "surfaced-matched" to the ceiling I get the critical error:

   ** Severe  ** ZoneHVAC:LowTemperatureRadiant:SurfaceGroup = LOW TEMP RADIANT ELEC SFLOORS does not have any surfaces listed.

As soon as one floor in the zone is set to a normal boundary condition (Outside) or Adiabatic conditions, the simulation runs.

Any ideas how to simulate a single floor of a TABS building? I'd upload photos but I don't have enough Karma yet.

Hi,

I'm trying to model a representative floor, similar to what is being done here, in question 1305. However, in my model I'm attempting to model radiant floors, without thermal isolation between the slab (like TABS). Splitting the slab and setting to adiabatic isn't ideal, as then the ceiling would no longer be a radiant surface, but rather just passive thermal mass.

In order to capture the heat transfer from the radiant floor to the ceiling of the floor below, I tried to manually surface-match the floor to the ceiling in each room. IE, the boundary condition of the floor is set to the ceiling of the same room.

This seems to create issues. It seems as if the "floor" is then converted to an internal mass object, similar to what happens to walls between spaces in the same thermal zone. I've set the default constructions for interior, ground and exterior surfaces all to internal source constructions, however once converted this doesn't seem to allow it to function as an internal source surface.

When I try to run with all the floor in a zone "surfaced-matched" to the ceiling I get the critical error:

   ** Severe  ** ZoneHVAC:LowTemperatureRadiant:SurfaceGroup = LOW TEMP RADIANT ELEC SFLOORS does not have any surfaces listed.

As soon as one floor in the zone is set to a normal boundary condition (Outside) or Adiabatic conditions, the simulation runs.

Any ideas how to simulate a single floor of a TABS building? I'd upload photos but I don't have enough Karma yet.