You also have to fashion a pick-up tube that goes down to the bottom of the tank to pick up the liquid. One of the local hardware stores has an assortment of plastic tubing and fittings. See if a store in your area has such things. But by the time you price out everything you need, it might be cheaper to get a whole new sprayer.

The code requirements for fireblocking can be found in the International Residential Code, which is the model code used for one- and two-family dwelling construction throughout most of the US. The code states the following: R602.8 Fireblocking required. Fireblocking shall be provided to cut off all concealed draft openings (both vertical and horizontal) and to form an effective fire barrier between stories, and between a top story and the roof space. Fireblocking shall be provided in wood-frame construction in the following locations. 1. In concealed spaces of stud walls and partitions, including furred spaces and parallel rows of studs or staggered studs; as follows: 1.1. Vertically at the ceiling and floor levels. 1.2. Horizontally at intervals not exceeding 10 feet (3048 mm). 2. At all interconnections between concealed vertical and horizontal spaces such as occur at soffits, drop ceilings and cove ceilings. 3. In concealed spaces between stair stringers at the top and bottom of the run. Enclosed spaces under stairs shall comply with Section R311.2.2. 4. At openings around vents, pipes, ducts, cables and wires at ceiling and floor level, with an approved material to resist the free passage of flame and products of combustion Products that can be used for fireblocking, as tested and certified by the ICC Evaluation Service, include Hilti CF810 Fireblocking foam, Dow Great Stuff (orange) fireblocking foam, and others. When evaluating a product for this application, look at the label to see if it mentions ICC-ES and fireblocking.

jdez you have good ideas but I would hate for guest to use my kids bathroom. We wanted them to have their own private space. That's the reason for two separate toilets. LOL Thank you for loving the layout. I give credit to our inspiration plan! Karenseb- the safe room is actually to conceal my husband gun safe and amno. We don't really have tornado's down here but hurricanes are a different story. Also the stairs go up to the bonus room over the garage. That will be the kids game/ tv space.

Thank you @kaseki and @robertgoulet for your insights and experience. I did some sound test last night (when it's super quiet). At maximum blower speed, I measured 65dB near the control knob both with and without the baffle. That suggests I have more than just baffle hiss at play here. I had a HVAC contractor do the 10'' ducting to roof, but the connection to the hood was made by another appliance installer, which, from what I can tell, did a sloppy job -- I can visually see kinks in the connection point when I look up from under the hood. The LD10 silencer just arrived and I'll have it installed in next few days. Will report back whether/how much it helps.