The brass helix is specially designed to activate & balance the wind element of the northwest corner. Place this helix at the northwest corner. This is one of the superb remedies for defects like missing or extended northwest corners, wrong entrance at the northwest, water body at the northwest, etc. Vastu defects of the northwest can be corrected by installing  3 or multiple brass energy helix in a northwest direction. If your main door is at the northwest corner (north side) corner, simply fix this helix above the main door to balance the energy.