Can two 120V outlets be converted to one 240V for stacked washer dryer combo?
Your unit already has a 240V dryer plug. Guaranteed.
An all-electric townhouse built in 1982 WILL have a 240V electric dryer plug in the laundry room.  Period, fullstop, end of subject.  You just haven't found it yet.
While you're searching, also search for a gas line.  That would be very surprising in a development that is all electric, because usually the whole point of going all-electric in a condo complex is to avoid even having to bring gas onto the property!   For instance my friend has an all-electric house, the entire square mile does not have gas lines.
I suspect you'll find no gas line.  If so, it is impossible for the building to receive an occupancy permit without a 240V dryer socket in the laundry area.  It MUST be there.
The longshot
Which makes no sense, because if the last guy did this, there'd be no way to dry clothes!!!!
Now, you know what the common 120V dual receptacle looks like.   Maybe you've also seen &quot;single&quot; 120V receptacles with a round socket instead of oval.  Each of those fits in a space we call a &quot;gang&quot; (no idea why).
If you're seeing two of those next to each other (say, 4 sockets, or 2 singles next to each other, or a duplex and a single) in a &quot;2-gang&quot; space with a basically square cover plate... then it's remotely possible that somebody hijacked the 240V dryer plug and replaced it with dual 120V circuits.
The hint is that a 240V dryer socket normally takes a 2-gang space.
Conversion in that direction is possible (240 to dual 120s).  And if that &quot;240 -&gt; dual-120&quot; conversion was done, it can be un-done.
Other than that, conversion in the other direction is not possible: you can't take any random pair of 120V circuits and turn them into a 240V circuit.
This all seems highly improbable... but as Sherlock Holmes says, when you eliminate the impossible (the townhouse not having any dryer power), what remains no matter how improbable must be the truth.