Just when I thought all of the hacks took the day off:
This is a 700 sq ft middle of the row house with insulation and new doors and windows, you could heat this place with a couple of hair dryers.
We usually do these with a 45k two stage set on first stage only.
This fellow decided 154k btu would work just fine. Return is one 8 inch, supply is two 10 inch flex duct one to a vent in living room, the other is doing the first and second floor via tees nothing is reducing the end of the flex goes through a hole punched in the brick wall termination in a powder room with a 10 by 10 sidewall return on the floor. Just don't stub your toe on these cheese graters.
The floor return is via a side wall grill, the guy looked like he was going to cut a larger hole but decided that might be too much air flow. For some reason the guy could not stop the heater from instantly shutting down on high limit, later with the blower compartment door removed and the door switch bypassed the heater worked good except that the flame was reversed through the burners and incinerated the sensor and hsi wires.
The question from the landlord was "Can we save the heater?", "Sure you just need a 4000 sq ft house to install it in".
I also got a few photos of the plumbing for one of my friends, most of the fitting that were cut in were rubber this include a 4 inch tee and most of the 90's. The best part is the all white plumbing pex, I asked the guy that did the plumbing hackery how he could tell the difference between the hot and cold, he said it didn't matter as all the faucets are one handled!?? Oh, sure? The corrugated hose sticking in a hole on the toilet waste is from the dishwasher. Don't worry the nearest vent stack is only 25 feet away.