Efficient Lower Casing in Excel VBA

Right now I use the below code to change an entire column to lower case.

I was wondering if there is a more efficient way to do this - I have around 150K rows in my worksheet.

It takes some time to complete and sometimes I get an Out of Memory error.

First Sub

Sub DeletingFl()
Dim ws1 As Worksheet
Dim rng1 As Range
Application.ScreenUpdating = False
Set ws1 = Sheets("Raw Sheet")

ws1.AutoFilterMode = False
Set rng1 = ws1.Range(ws1.[a1], ws1.Cells(Rows.Count, "A").End(xlUp))
rng1.AutoFilter 1, "Florida"
    If rng1.SpecialCells(xlCellTypeVisible).Count > 1 Then
    Set rng1 = rng1.Offset(1, 0).Resize(rng1.Rows.Count - 1)
    rng1.EntireRow.Delete
    End If
ws1.AutoFilterMode = False    
Call DeletingEC
End Sub

Sub DeletingEC()
Dim ws1 As Worksheet    
Dim rng1 As Range
Application.ScreenUpdating = False
Set ws1 = Sheets("Raw Sheet")

ws1.AutoFilterMode = False
Set rng1 = ws1.Range(ws1.[a1], ws1.Cells(Rows.Count, "A").End(xlUp))
rng1.AutoFilter 1, "East Coast"
If rng1.SpecialCells(xlCellTypeVisible).Count > 1 Then
    Set rng1 = rng1.Offset(1, 0).Resize(rng1.Rows.Count - 1)
    rng1.EntireRow.Delete
End If
ws1.AutoFilterMode = False
Worksheets("Raw Sheet").Activate    
Call Concatenating
End Sub

Second Sub

Sub Concatenating()

Columns(1).EntireColumn.Insert
Columns(2).EntireColumn.Copy Destination:=ActiveSheet.Cells(1, 1)

Dim lngLastRow As Long
lngLastRow = Cells(Rows.Count, "A").End(xlUp).Row

    Range("A2:A" & lngLastRow).Formula = "=F2 & ""_"" & G2"
Range("A1").Select
    ActiveCell.FormulaR1C1 = "Title"       
Call LowerCasing
End Sub

Sub Lowercasing()
Dim myArr, LR As Long, i As Long
       LR = Range("A" & Rows.Count).End(xlUp).Row
myArr = Range("A1:A" & LR)
       For i = 1 To UBound(myArr)
              myArr(i, 1) = LCase(myArr(i, 1))
       Next i
Range("A1:A" & LR).Value = myArr
Set ExcelSheet = Nothing
End Sub