We put in new complete air conditioning in J Street, does this count as an improvement, because we replaced the old unit?

[HelenC12]

If J Street is your rental or business, yes, installing a new air conditioner is considered an improvement and is depreciated because it adds value to the property. 

Capital improvements that add to the value of your property, prolong its life, or adapt it to new uses must be depreciated over a period of time rather than deducted as a current-year expense. This would include things like:

• Remodels and room additions (including decks and porches)
• New or upgraded landscaping, irrigation, sprinkler system
• Hardscape such as pavement, block or retaining wall, patio
• Fencing
• Swimming pool, spa
• Storm windows, doors
• New roof
• Central vacuum or security system
• Upgraded wiring, plumbing, duct work
• Central heating, AC, humidifier
• New furnace, water heater
• Filtration, soft-water, or septic system
• Built-in appliances
• New flooring or wall-to-wall carpeting
• Upgraded insulation
• Satellite dish