An emergency fund is for the money you set aside in a savings account for unexpected costs you may face when losing a job, boiler breaks, a medical necessity, or pet surgery. The sinking fund is for saving money for a known purpose you expect to purchase in the future. Typically, your sinking fund is for a specific planned amount.
Please make a list of sinking fund categories, break them down into more specific items. Then determine the target amounts for each. Name your sinking fund by its discreet type. Some funds may have higher amounts and longer timeframes.
You can open an FDIC-insured saving account for each type or have one large sinking fund named sub-accounts. Keep in mind that the sinking funds are separate from your emergency fund and savings accounts. The type of accounts you should look for should be readily accessible and liquid, similar to the account you use for an emergency fund.