procedure can be substantially the same though rotated 90 degrees in all respects a system installed in this manner would not have the benefit of gravity as in the top down system and thus may need to be manually deployed the system would nonetheless function as intended as shown in fig1 in still other embodiments the system 1200 can be completely manually deployed in other words the system 1200 can comprise retention channels 110 and the screen 120 with no enclosure 130 or deployment mechanisms 1020 in this configuration the user can simply install the retention channels 110 on either side of the penetration 1205 and then slide the screen 120 down over the hem rods 105 and into the retention channels 110 the screen 120 can then be secured at the bottom and or the top of the penetration 1205 as desired this configuration can be useful if the subject building is for example a summer home the user can deploy screen 120 over some or all of the external building penetrations at the end of the season the user can then remove the screens 120 at the beginning of the season when reopening the house because there is no hem cord the screens 120 can be stacked and stored flat or rolled up for storage in minimal space in addition because the system is somewhat simplified e g there is no enclosure 130 or deployment mechanisms 1020 the cost of purchasing installing and maintaining the system 1200 is reduced finally the aesthetic impact to the structure is minimized because when removed only the retention channels 110 remain on the building in some embodiments the retention channels 110 can also be removable further reducing aesthetic impact while several possible embodiments.