diff --git a/test/conservation_checker_tests.jl b/test/conservation_checker_tests.jl
index b5bcf1afb1..4a8f3f51df 100644
--- a/test/conservation_checker_tests.jl
+++ b/test/conservation_checker_tests.jl
@@ -25,32 +25,55 @@ struct TestAtmos{I} <: Interfacer.AtmosModelSimulation
     i::I
 end
 name(s::TestAtmos) = "TestAtmos"
+function get_field(s::TestAtmos, ::Val{:F_radiative_TOA})
+    FT = Domains.float_type(Meshes.domain(s.i.space.grid.topology.mesh))
+    ones(s.i.space) .* FT.(200)
+end
+function get_field(s::TestAtmos, ::Val{:energy})
+    FT = Domains.float_type(Meshes.domain(s.i.space.grid.topology.mesh))
+    ones(s.i.space) .* FT.(1e6)
+end
+function get_field(s::TestAtmos, ::Val{:water})
+    FT = Domains.float_type(Meshes.domain(s.i.space.grid.topology.mesh))
+    ones(s.i.space) .* FT.(1)
+end
 
 struct TestOcean{I} <: Interfacer.SurfaceModelSimulation
     i::I
 end
 name(s::TestOcean) = "TestOcean"
+function get_field(s::TestOcean, ::Val{:energy})
+    FT = Domains.float_type(Meshes.domain(s.i.space.grid.topology.mesh))
+    ones(s.i.space) .* FT.(1e6)
+end
+function get_field(s::TestOcean, ::Val{:water})
+    FT = Domains.float_type(Meshes.domain(s.i.space.grid.topology.mesh))
+    ones(s.i.space) .* FT.(0)
+end
+function get_field(s::TestOcean, ::Val{:area_fraction})
+    FT = Domains.float_type(Meshes.domain(s.i.space.grid.topology.mesh))
+    ones(s.i.space) .* FT.(0.25)
+end
 
 struct TestLand{I} <: Interfacer.SurfaceModelSimulation
     i::I
 end
 name(s::TestLand) = "TestLand"
-
+function get_field(s::TestLand, ::Val{:energy})
+    FT = Domains.float_type(Meshes.domain(s.i.space.grid.topology.mesh))
+    ones(s.i.space) .* FT.(0)
+end
+function get_field(s::TestLand, ::Val{:water})
+    FT = Domains.float_type(Meshes.domain(s.i.space.grid.topology.mesh))
+    ones(s.i.space) .* FT.(0)
+end
+function get_field(s::TestLand, ::Val{:area_fraction})
+    FT = Domains.float_type(Meshes.domain(s.i.space.grid.topology.mesh))
+    ones(s.i.space) .* FT.(0.25)
+end
 
 
 for FT in (Float32, Float64)
-    global get_field(s::TestAtmos, ::Val{:F_radiative_TOA}) = ones(s.i.space) .* FT.(200)
-    global get_field(s::TestAtmos, ::Val{:energy}) = ones(s.i.space) .* FT.(1e6)
-    global get_field(s::TestAtmos, ::Val{:water}) = ones(s.i.space) .* FT.(1)
-
-    global get_field(s::TestOcean, ::Val{:energy}) = ones(s.i.space) .* FT.(1e6)
-    global get_field(s::TestOcean, ::Val{:water}) = ones(s.i.space) .* FT.(0)
-    global get_field(s::TestOcean, ::Val{:area_fraction}) = ones(s.i.space) .* FT.(0.25)
-
-    global get_field(s::TestLand, ::Val{:energy}) = ones(s.i.space) .* FT.(0)
-    global get_field(s::TestLand, ::Val{:water}) = ones(s.i.space) .* FT.(0)
-    global get_field(s::TestLand, ::Val{:area_fraction}) = ones(s.i.space) .* FT.(0.25)
-
     @testset "test check_conservation for conservation for FT=$FT" begin
         space = TestHelper.create_space(FT)
 
diff --git a/test/diagnostics_tests.jl b/test/diagnostics_tests.jl
index 4e0a3bd8d4..2ba04fc9c6 100644
--- a/test/diagnostics_tests.jl
+++ b/test/diagnostics_tests.jl
@@ -19,10 +19,9 @@ import ClimaCoupler.Diagnostics:
     post_save,
     save_time_format
 
+get_var(cs::Interfacer.CoupledSimulation, ::Val{:x}) = float_type(cs)(1)
 
 for FT in (Float32, Float64)
-    global get_var(cs::Interfacer.CoupledSimulation, ::Val{:x}) = FT(1)
-
     @testset "init_diagnostics for FT=$FT" begin
         names = (:x, :y)
         space = create_space(FT)
diff --git a/test/flux_calculator_tests.jl b/test/flux_calculator_tests.jl
index 0c89c1e982..d5bab403e7 100644
--- a/test/flux_calculator_tests.jl
+++ b/test/flux_calculator_tests.jl
@@ -110,6 +110,14 @@ function get_thermo_params(sim::TestAtmos)
     TP.ThermodynamicsParameters{FT}(; pairs...)
 end
 
+function get_surface_params(sim::TestAtmos)
+    FT = sim.params.FT
+    toml_dict = CP.create_toml_dict(FT; dict_type = "alias")
+    sf_params = create_parameters(toml_dict, UF.BusingerType())
+    return sf_params
+end
+
+
 # ocean sim object and extensions
 struct TestOcean{M, Y, D, I} <: Interfacer.SurfaceModelSimulation
     model::M
@@ -208,10 +216,6 @@ for FT in (Float32, Float64)
         @test_throws ErrorException calculate_surface_air_density(sim2, coupler_fields.T_sfc)
     end
 
-    toml_dict = CP.create_toml_dict(FT; dict_type = "alias")
-    sf_params = create_parameters(toml_dict, UF.BusingerType())
-    global get_surface_params(::TestAtmos) = sf_params
-
     @testset "calculate correct fluxes: dry for FT=$FT" begin
         surface_scheme_list = (MoninObukhovScheme(), BulkScheme())
         for scheme in surface_scheme_list
@@ -321,7 +325,10 @@ for FT in (Float32, Float64)
     end
 
     @testset "get_surface_params for FT=$FT" begin
-        @test get_surface_params(TestAtmos([], [], [], [])) == sf_params
+        toml_dict = CP.create_toml_dict(FT; dict_type = "alias")
+        sf_params = create_parameters(toml_dict, UF.BusingerType())
+
+        @test get_surface_params(TestAtmos((; FT = FT), [], [], [])) == sf_params
         sim = DummySimulation([], [])
         @test_throws ErrorException(
             "get_surface_params is required to be dispatched on" * Interfacer.name(sim) * ", but no method defined",
diff --git a/test/interfacer_tests.jl b/test/interfacer_tests.jl
index ee6a3f129c..e1f503d0c9 100644
--- a/test/interfacer_tests.jl
+++ b/test/interfacer_tests.jl
@@ -17,16 +17,24 @@ import ClimaCoupler.Interfacer:
     update_field!
 
 # test for a simple generic surface model
-struct DummySimulation <: SeaIceModelSimulation end
-struct DummySimulation2 <: OceanModelSimulation end
-struct DummySimulation3 <: LandModelSimulation end
+struct DummySimulation{S} <: SeaIceModelSimulation
+    space::S
+end
+struct DummySimulation2{S} <: OceanModelSimulation
+    space::S
+end
+struct DummySimulation3{S} <: LandModelSimulation
+    space::S
+end
 
-for FT in (Float32, Float64)
-    boundary_space = TestHelper.create_space(FT)
-    global get_field(::SurfaceModelSimulation, ::Val{:var}) = ones(boundary_space)
-    global get_field(::SurfaceModelSimulation, ::Val{:var_float}) = FT(2)
-    global get_field(::SurfaceModelSimulation, ::Val{:surface_temperature}) = ones(boundary_space) .* FT(300)
+get_field(sim::SurfaceModelSimulation, ::Val{:var}) = ones(sim.space)
+get_field(sim::SurfaceModelSimulation, ::Val{:surface_temperature}) = ones(sim.space) .* FT(300)
+function get_field(sim::SurfaceModelSimulation, ::Val{:var_float})
+    FT = Domains.float_type(Meshes.domain(sim.space.grid.topology.mesh))
+    FT(2)
+end
 
+for FT in (Float32, Float64)
     @testset "test CoupledSim construction, float_type for FT=$FT" begin
         cs = CoupledSimulation{FT}(
             nothing, # comms_ctx
@@ -50,7 +58,8 @@ for FT in (Float32, Float64)
     end
 
     @testset "get_field indexing" begin
-        for sim in (DummySimulation(), DummySimulation2(), DummySimulation3())
+        space = TestHelper.create_space(FT)
+        for sim in (DummySimulation(space), DummySimulation2(space), DummySimulation3(space))
             # field
             colidx = Fields.ColumnIndex{2}((1, 1), 73)
             @test parent(get_field(sim, Val(:var), colidx))[1] == FT(1)
@@ -60,14 +69,14 @@ for FT in (Float32, Float64)
     end
 
     @testset "undefined get_field" begin
-        sim = DummySimulation()
+        space = TestHelper.create_space(FT)
+        sim = DummySimulation(space)
         val = Val(:v)
         @test_throws ErrorException("undefined field $val for " * name(sim)) get_field(sim, val)
     end
 
     # test for a simple generic surface model
     @testset "get_field for a SurfaceStub" begin
-
         toml_dict = CP.create_toml_dict(FT; dict_type = "alias")
         aliases = string.(fieldnames(TDP.ThermodynamicsParameters))
         param_pairs = CP.get_parameter_values!(toml_dict, aliases, "Thermodynamics")