Anonymous wrote:We have high velocity ac, unit is on the roof. Pulls in air, cools it, and pushes it down throughout our house.

Unit is outside on the roof because there's room for it there, not so it can pull in outside air. I really, really doubt it does. It would have to do a huge amount of extra work dehumidifying the outside air.

Anonymous wrote:

Anonymous wrote:Our 1920s Rowhouse had gaps between houses above the ceiling and plaster wall where beams overlap. This was visible when we took down the ceilings. This was a significant cause of smoke penetration into our house when the neighbor had a bad fire - our beams were blackened from traveling soot rather than actual flames.

That being said, not sure the actual risk when we have ceilings in place. Not very likely and we don't share active ventilation systems such as AC, which draws air from outside.

Are you sure about that?

We have high velocity ac, unit is on the roof. Pulls in air, cools it, and pushes it down throughout our house.

No they don’t. Firewalls between units and no shared ventilation.

Generally no, but I'm sure there are some weird exceptions out there. On my list of covid danger points it ranks about the same walking down the sidewalk outside with no one around.

Anonymous wrote:Our 1920s Rowhouse had gaps between houses above the ceiling and plaster wall where beams overlap. This was visible when we took down the ceilings. This was a significant cause of smoke penetration into our house when the neighbor had a bad fire - our beams were blackened from traveling soot rather than actual flames.

That being said, not sure the actual risk when we have ceilings in place. Not very likely and we don't share active ventilation systems such as AC, which draws air from outside.

Are you sure about that?

Our 1920s Rowhouse had gaps between houses above the ceiling and plaster wall where beams overlap. This was visible when we took down the ceilings. This was a significant cause of smoke penetration into our house when the neighbor had a bad fire - our beams were blackened from traveling soot rather than actual flames.

That being said, not sure the actual risk when we have ceilings in place. Not very likely and we don't share active ventilation systems such as AC, which draws air from outside.

Technically no, we have our own HVAC and duct system with a cinder block dividing wall. However, my (Asian) neighbors cook a lot and I can frequently smell Asian food in our basement at night, so it gets in somehow.

Absolutely not.

For example, our townhouses have wood-burning fireplaces. I never have smoke smell in my house when my neighbor is using theirs.

Fire breaks between houses. No shared A/C or vents.

Depends on how they are constructed. Mine, which is older, does not. We have a cement block firewall between the units, including all the way up to the roofline. No crossing of any air inside the units.

Asking for covid purposes, obviously.