Apparently, the A/C has gone out in one of our units in Bel Air, MD. 

How's that for a lot of hot air with an unexpected conclusion?

., former employer 401k) to a solo 401k are not reported on Form 5498, but rather on Form 5500-EZ, but only if the air market value of the solo 401k exceeds $250K as of the end of the plan year (generally 12/31);When funds are rolled over or transferred from an IRA or 401k to a self-directed IRA, the amount deposited into the self-directed IRA is reported on Form 5498 by the receiving self-directed IRA custodian by May of the year following the rollover/transfer.Rollovers (provided the 60 day rollover window is satisfied) from an IRA to a Solo 401k or self-directed IRA are reported on lines 15a and 15b of Form 1040;Pre-tax IRA contributions on reported on line 32 of Form 1040;Pre-tax solo 401k contributions are reported on line 28 of Form 1040;Roth solo 401k funds are subject to RMDs;A Roth 401k may be transferred to a Roth IRA (Note that from a planning perspective, it may be advantageous to transfer Roth Solo 401k funds to a Roth IRA before turning age 70 ½ in order to escape the Roth RMD requirement applicable to Roth 401k contributions including Roth Solo 401k contributions and earnings.)

Keep in mind if you are thinking about Air BnB, there are only so many permits allowed for each area.

Oops, no air miles ;-(Ali, are you in a rent controlled unit? 

They recommendations air quality inspection to protect us .

I'm a military Veteran with 21 years of active duty service in the United States Air Force. 

Total rents : $1,602Mortgage: $525Taxes: $219Ins: $85 Water/Sewer/Trash: $117Repairs: $160Vacancy (5%) - $80.10 Capex (5%) - $80.10 New roof, newer water heaters, newer furnaces, new central air unit, so capex shouldn't be a big expense for awhile.Numbers will be better when I raise rents but this is current breakdown.

A vapor barrier stops air water vapors from passing thru a material or space. 

I'd look into the possibility of installing heat pumps with electric heating elements for very cold days(one per unit, hopefully, in the units which currently have electric heat) these can be installed in the window much like typical air conditioners and they will function as air conditioners in the summer- some can be installed through the wall.