@catusmc wrote:
How can I determine this for previous years. In my case, 2021.
If you installed an efficient appliance in 2021, the credit can only be claimed on your 2021 tax return, using the rules in place at the time. In 2021, there was a lifetime cap on all credits for energy efficient improvements of $500. If you had not exceeded the cap by 2021, the credit was 10% of cost plus installation, with a maximum of $50 for any advanced main air circulating fan; $150 for any qualified natural gas, propane, or oil furnace or hot water boiler; and $300 for any item of energy efficient building property (which includes the air conditioner unit). So the maximum credit for installing an efficient system could be as much as $500, but each component (fan, furnace and a/c) must meet its own individual standard, and you can't have exceeded the lifetime cap in a prior year.
For 2021, the efficiency standard was
• An electric heat pump water heater that yields a Uniform Energy Factor of at least 2.2 in the standard Department of Energy test procedure.
• An electric heat pump that achieves the highest efficiency tier established by the Consortium for Energy Efficiency (CEE) as in effect on January 1, 2009.
• A central air conditioner that achieves the highest efficiency tier that has been established by the CEE as in effect on January 1, 2009.
• A natural gas, propane, or oil water heater that has a Uniform Energy Factor of at least 0.82 or a thermal efficiency of at least 90%.
You would have to check with the manufacturer, or the CEEE web site, or your product instruction manuals, to determine if it met the required efficiency standard.
