Will an 84 year old who has an IRA be penalized for taking $20,000 out to do a home repair?

No - early withdrawal penalties apply only to people under 59-1/2 years of age.

If this is a traditional IRA anyone over age 70-1/2 is REQUIRED to take minimum annual distributions - at age 84 the required minimum distribution is 6.45% of the account value. Income tax will be owed on the portion of the withdrawal attributable to pre-tax contributions and earnings.

If this is from a Roth account that has been in existence at least 5 years the withdrawal is tax free, and there is no mimumum required annuall withdrawal.