jimcatinmi wrote:
If we are not going to run the A/C can we use20amp service safely? I o ly have 20 amp athome a dI use an adapter to run the fridge and lights but what if we need to use the furnace would that be safe?
Yes. You are safe running as you describe, including the furnace.
As to the answers saying you can run your AC, that is technically correct but a very incomplete answer. You could be causing damage to your AC. If the voltage drops below 104, the AC will start accumulating damage. You are not likely to see it but it will likely cause your AC to fail before it's life expectancy.
If you want to run the AC, put in an EMS that can shut off electricity below 104 volts. I have been to a park where my PI EMS saw the electricity drop to 97 and then the PI shut off my electricity. If you do not have an EMS, at least get a Kill-A-Watt to monitor electricity, when you turn on the AC.