What evidence should change your sizing decision?
| Evidence | How to use it |
|---|---|
| HVAC model and electrical data | Identify the equipment being evaluated |
| Soft-starter compatibility confirmation | Establish that the proposed combination is supported |
| Recorded startup before and after installation | Compare the same system under documented conditions |
| Generator model, fuel and output | Check the power source actually proposed |
| Other loads during the start | Avoid mistaking an isolated demonstration for a whole-home test |
Micro-Air’s generator-sizing guidance explicitly says its estimates vary with manufacturer and model family and assumes no other significant household loads during compressor startup. Its chart is not a promise that the same generator will operate the rest of your home simultaneously. Micro-Air sizing guidance.
Questions for the HVAC contractor
Ask whether the exact compressor and control system support the proposed device, whether the installation affects any applicable warranty terms, and what documentation will be supplied after commissioning. Have the contractor identify the device model and installation instructions in the quote.
Ask for the measured conditions as well as the result: supply source, other operating loads, measurement method and whether the compressor restarted successfully. This guide does not supply an assumed percentage reduction because we have not measured your installation.
A comparison worksheet
| Record | Before | After |
|---|---|---|
| HVAC model | Enter exact model | Same equipment or explain change |
| Starting measurement and units | Contractor measurement | Contractor measurement |
| Other active loads | List | List |
| Power source | Utility or exact generator | Utility or exact generator |
| Successful repeated starts | Record conditions | Record conditions |
Do not substitute nameplate locked-rotor amps for an observed start without the contractor explaining the distinction. Read the central-air sizing guide for the broader equipment assessment.
When should you compare another solution?
If the documented combination still does not meet the backup plan, compare a different generator or load management. Obtain a quote that states which cooling loads will run and what else can operate with them. The generator size calculator can organize the household load list, but final compatibility and starting performance require professional confirmation.