How do I add range of cells with text and numbers but only include cells with certain text?

[linnk]

[TABLE="class: grid, width: 160"]
<colgroup><col width="80" span="2" style="width:60pt"> </colgroup><tbody>[TR]
[TD="width: 80"]A[/TD]
[TD="width: 80"]B[/TD]
[/TR]
[TR]
[TD]NA[/TD]
[TD]NA[/TD]
[/TR]
[TR]
[TD]4.6 U[/TD]
[TD]23 U[/TD]
[/TR]
[TR]
[TD]1.5 U[/TD]
[TD]7.5 U[/TD]
[/TR]
[TR]
[TD]4.7 U[/TD]
[TD]24 U[/TD]
[/TR]
[TR]
[TD]52[/TD]
[TD]52[/TD]
[/TR]
[TR]
[TD]280[/TD]
[TD]400[/TD]
[/TR]
[TR]
[TD]84 U[/TD]
[TD]420 UJ[/TD]
[/TR]
[TR]
[TD]NA[/TD]
[TD]NA[/TD]
[/TR]
[TR]
[TD]25 UJ[/TD]
[TD]120 UJ[/TD]
[/TR]
[TR]
[TD]NA[/TD]
[TD]NA[/TD]
[/TR]
[TR]
[TD]3,400 D[/TD]
[TD]3,300 J[/TD]
[/TR]
[TR]
[TD]25 U[/TD]
[TD]120 U[/TD]
[/TR]
[TR]
[TD]5 U[/TD]
[TD]25 U[/TD]
[/TR]
[TR]
[TD]26 U[/TD]
[TD]0.5 U[/TD]
[/TR]
[TR]
[TD]22 U[/TD]
[TD]0.51 U[/TD]
[/TR]
</tbody>[/TABLE]

Above are two scenarios (column A and B). I have a formula that will ignore all text, but what formula will sum the individual columns including only cells containing the letter "U" (U, UJ, UJB etc.)? The array formulas (ctrl+shft+enter) I've been using return #value if the number of digits in a cell change from one column to the next. A formula for a fixed number of digits will not work because the number of digits vary from one column to the next.

for example:
=SUM(IF((RIGHT(B1:B15,1))="U",(--LEFT((IF(B1:B15="",0,B1:B15)),3)),0)) works for Column B but not for Column A and only finds "U". I need it to find any text that includes "U" and work with a variance of number lengths rather than the left 3 digits.

Thanks in advance for your help.

 

[onlyadrafter]

Hello,

=SUM(IF(NOT(ISERROR(FIND("U",A1:A15))),(--LEFT(IF(A1:A15="",0,A1:A15),FIND(" ",A1:A15)))))

this gives 197.8 for Col A and 740.51 for Col B. Are these correct?

This is an array formula, so CTRL + SHIFT + ENTER required.

 

[linnk]

Works beautifully, thanks!