@Inna R
Because they are both required at the same time for installation, add the two costs and enter the total, 16K as a fixed asset.
The fixed asset should be a sub account of the fixed asset building account and it uses the same depreciation schedule as the rental property but posts its depreciation to its own account. ie...
123 some street
>> land
>> building
>> >> accumulated depreciation building
>> heat pump
>> >> accumulated depreciation heat pump
at tax time talk to the tax accountant about bonus depreciation if you still want to try to take as much of it as you can as an expense as opposed to using annual depreciation
