Adding extra insulation?

[chlinthi]

Hey all.

I have a Jay Feather 213EXP. I recently spent 1/2 a day tearing behind cabinets to get to all the water lines to insulate them with some pipe insulation to cut down on the water pump 'hammering' noise. In the process of doing this I noticed a lot of dead space behind the cabinets and wonder if anyone has thought of adding regular insulation material here to help reduce heat loss, etc. I'm not sure what type of insulation I should look for when shopping at Home Depot or Lowe's though. If anyone has experience doing this, please share your BKM's.

Thanks,

-Chip