Upon arrival I spoke with receptionist and she informed me that front area was cold last night and into this morning. Found both thermostats in front reading 69, set for 72. Went to roof and found both units 1 and 2 operating at max capacity. Found normal heat rise on both systems. Checked gas pressures and found them to be in spec. Kept running systems and checked specs twice afterwards and found them to be identical so it doesn’t appear that either unit is faulting, just not keeping up. Verified all economizers are closed and not pulling in outdoor air. Units are heating as much as they can. Systems are all now 22 years old. Customer may want to get an estimate to see if they need to increase the unit size(s).