Wednesday Words ~ fridge

Why is there a D in "fridge" but not in "refrigerator"?  What I found when I googled was no help:

fridge \'frij\ = a refrigerator
Merriam-Webster says, "The first known use of fridge was in 1926."

What about refrigerator?

refrigerator \ri-'fri-jə-ˌrā-tər\ = something that refrigerates
Merriam-Webster says, "The first known use of refrigerator was in 1611."

What about "frigid"?  It has a D in it.

frigid \'fri-jəd\ = intensely cold
Merriam-Webster says, "The first known use of frigid was in 1619."

English is so weird.  We know these common words, but put them together in one sentence and it CAN be a bit funny.  Here's my single sentence using all three of these words:

It's the frigid air inside a refrigerator that makes a fridge useful, right?

Do you ever wonder about common words we use every day?  This time, it isn't so much the words that are odd, but the spelling of one of them.  And nowhere have I found why that extra D is in the spelling of "fridge."  Let's try again, googling "etymology of fridge":

Fridge is a shortened and altered form of refrigerator, 1926, an unusual way of word-formation in English; perhaps influenced by Frigidaire (1919), name of a popular early brand of self-contained automatically operated iceless refrigerator (Frigidaire Corporation, Detroit, Michigan, U.S.), a name suggesting Latin frigidarium "a cooling room in a bath."  Frigerator as a colloquial shortening is attested by 1886.

I found that paragraph here.  Interestingly, just above this was an ad for a "22 cubit foot 36-inch width counter depth French door refrigerator" for $1,749.50.  Apparently the advertising world thinks anyone looking up "fridge" must be in the market to buy one.