If a modern home is built too tightly, the air change rate per hour is reduced. ventilation may be increased to safe levels by

Mechanical ventilation system

Explanation:

Ventilation can be increased to safe levels by using mechanical ventilation system to bring in more fresh air.

There are many ways to provide ventilation for example

the higher the current the higher the mag field around it the higher the influence on the compass

the answer is ampere

the ampere is used to measure electricity. an ampere is a unit of electric current equal. a unit of measure for the flow of current in a circuit. one ampere is the amount of current flow provided when one volt of electrical pressure is applied against one ohm of resistance.