welcome to the forums...
#1 It would be very hard to meld a Harman stove (if you loaded it... then left the bottom door open... you would likely see some of those 1/4" walls/top plate buckle or warp and get cherry red... but not melt).
#2 If thats your basement than you have one nice fireplace set up in your basement! so let do some serious cartwheels for that alone!
#3 do you have a blocker plate of some sort sealing the area around where that stove pipe goes through the damper opening in that fireplace? (if not... do it by reading threads about blocker plate options)
#4 i notice that fan on the floor right in front of the stove (this is a VERY fine line to walk because you could be introducing a forced air draft into your stove with that)... this would make your burn times MUCH less and the stove MUCH hotter and a lot of MUCH wasted fuel. (that stove NEEDS a proper working blower on it... if you dont have one....get one!) be very careful how if using that floor fan the direction its facing (at stove will produce a forced draft, away from stove could effect suction from the primary draft) and how you use it, typically id rather see a smaller metal fan way back in the fireplace facing out (if space allows)
#5 the most common problem i see with the Harman (or even on my Crane 404 and many others)... is getting a complete shake down and complete load up! one this stove your likely going to need to play the poke N scrape game (shake it good for a minute, then open bottom door and scrape under the grates, then poke through top door to "settle" the coal bed more, then shake again... then leave bottom open for a min or two to get a nice hot fire... then load it up heaping and as evenly as possible across the entire coal bed... then leave the bottom door open another couple minutes to help burn off volatiles and not loose temps to drastically... then close it down, adjust primary draft knobs/mpd and let her ride for 12-24 hours depending on temps outside (when its 0 degrees none of us are going 24 hour cycles... 12 hour cycles is normal).
#6 I dont see a MPD or a Baro (I know Harman is hellbent that their stoves for some magical reason dont ever need a Baro or MPD in the stove pipe.... THEY ARE WRONG... these are items that are part and parcel to good, true, expert coal burners! learn about them... understand them... utilize them to your benefit!
#7 you can learn to keep that dust/mess to a minimum by searching "reducing ash mess dust" or here is one regarding Harman dust in particular OHHH THE DUST!!!!!
#8 Everyone knows i dont particularly like Harman (my own personal issues)... but if I had a Harmon... yours would be the model Id have!
best wishes to you and we all hope you stay on board with us here as a friend and fellow coal queen!
P.S. you can use the search area at the upper right of screen to search & learn about anything regarding coal burning, coal stoves, YOUR stove, etc... type in "Baro or MPD", "Harman SF 250", "Longer burn times", etc.etc.etc... you can learn for years here and still not know everything (like me