There is not a statute per se for commercial leases, as maintenance and repair of HVAC units is usually defined under the lease in commercial leasing siutation. (NOTE: the answer would be different for a residential lease under Chapter 118A of the Nevada Revised Statutes). You should have your lease reviewed by a real estate attorney. Usually maintenance of the HVAC Unit is the Tenant's responsibility but replacement of the HVAC is considered a capital improvement for which the Landlord may be responsible since the benefit of a new HVAC unit would inure to future tenants after your two years is up.
Answered on Sep 16th, 2013 at 12:28 PM