Welcome to the Rural Energy "E" Glossary Terms!

A ratio calculated by dividing the cooling capacity in Btu’s per hour (Btuh) by the power input in watts at any given set of rating conditions, expressed in Btuh per watt (Btuh/watt). EER & SEER can not be compared equally. Air source equipment is rated by SEER and geothermal equipment is rated by EER. EER changes with the inside and outside conditions, falling as the temperature difference between inside and outside gets larger.

The measure of how effectively a heating system converts energy input into useful heat output, typically expressed as a percentage.

The measure of how effectively an oil heater converts fuel into heat energy, typically expressed as a percentage.

A heating and cooling system that uses electricity to transfer heat between indoor and outdoor environments, providing efficient heating and cooling year-round.

A heating system that uses electric resistance cables or heating mats installed beneath flooring or within walls or ceilings to radiate heat into a room.

A certification program by the U.S. Environmental Protection Agency (EPA) that identifies energy-efficient heating and cooling equipment meeting specific performance criteria.

Troubleshooting codes on Toyotomi heaters

A component in heat pump systems that absorbs heat from indoor air or refrigerant, causing liquid refrigerant to evaporate into a gas for efficient heat transfer.

Exhaust refers to the byproducts of combustion, such as gases, smoke, and particulate matter, that are expelled from a heating appliance through a venting system. Proper exhaust ventilation is essential for removing these combustion byproducts from the indoor environment, ensuring safe and efficient operation of the heating appliance while maintaining indoor air quality.

A flexible joint or connector used in piping systems to accommodate thermal expansion and contraction, preventing damage to components in heating systems.

A vessel used in hydronic heating systems to accommodate the expansion and contraction of water due to temperature changes, preventing pressure buildup.