XL Formula help required- sum a range of cells which meet a specific criteria

I have the following data in XL:

Drive Letter Name Total Cap Free Cap Lun_ID RAID LVL RAID_GRP
C -- 140 38 -- -- --
D DATA 1600 435 50 5 4
L LOG 300 23 30 1/0 3


50:05:08:b2:00:be:de:e2 \\.\Scsi2
50:05:08:b2:00:be:de:e3 \\.\Scsi3

Drive Letter Name Total Cap Free Cap Lun_ID RAID LVL RAID_GRP
C -- 280 99 -- -- --
D DATA2 573 277 191 5 19


50:05:08:b2:00:bf:22:a2 \\.\Scsi2
50:05:08:b2:00:bf:22:a3 \\.\Scsi3

Drive Letter Name Total Cap Free Cap Lun_ID RAID LVL RAID_GRP
C -- 280 242 -- -- --
D DATA 1200 481 200 5 4
L LOG 30 30 31 1/0 3

I want to create a formula which looks at the RAID_GRP column, find anything which matches "4" and sums the values in the Total Cap column. For example, there are two entries for RAID_GRP = 4, where the Total Cap column equals: 1600 + 1200. My formula should thus give me a result of 2800.

If I create another formula where RAID_GRP = "3", then my formula should give me 300 + 30 = 330.

I tried the following dynamic formula:

=SUM(((I14:I42=4)*1)*(E14:E42))

Entered using CTRL-SHFT-ENTER, but I'm getting "#Value" as when it gets to the text parts of a cell, it cannot compute it. Thus, for this formula, I'm getting:

=SUM(({FALSE;TRUE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;FALSE;TRUE;FALSE}*1)*{140;1600;30;0;0;0;0;0;"Total Cap";280;573;0;0;0;0;0;"Total Cap";280;1200;30})

Which then equates to:

=SUM({0;1;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;0;1;0}*{140;1600;30;0;0;0;0;0;"Total Cap";280;573;0;0;0;0;0;"Total Cap";280;1200;30})

....and....

=SUM({0;1600;0;0;0;0;0;0;#VALUE!;0;0;0;0;0;0;0;#VALUE!;0;1200;0})

So, I thus need to "remove" the text values from the equation, unless there is a better way to do this.

I was over-engineering the concept and found this as the answer:

Try: =SUMIF(I1:I21,4,E1:E21)

Where I1:I21 is the RAID_GRP column and E1:E21 the Total Cap column.

This works sweet! Thanks for your help!