The late 19th century saw the development of mechanical refrigeration systems, primarily used in industrial settings like breweries and meatpacking plants. These early systems were large, expensive, and often relied on hazardous refrigerants like ammonia.

The early 20th century brought advancements in refrigeration technology that led to the development of smaller, more efficient, and safer refrigeration units suitable for commercial and residential use. These advancements made refrigeration more accessible to a wider range of businesses and households.

The mid-20th century witnessed the expansion of refrigerated transport and distribution networks, enabling the widespread movement of perishable foods across long distances. This development was crucial for ensuring a consistent supply of fresh produce and other perishable goods to consumers nationwide.

Throughout her career, Pennington actively engaged with the advances in refrigeration technology. Her research focused on optimizing refrigeration practices for food preservation, developing standards for refrigerated transport, and promoting the adoption of refrigeration technologies in the food industry. Her expertise was essential in bridging the gap between technological innovation and practical application.