A Heating System defines how a building's spaces are heated. The system covers how heating is generated and delivered to spaces. Following is a full list of the current systems options in cove.tool which covers all code baselines and more energy efficiency solutions. To see how each of these systems interacts with specific air and cooling systems refer to the System Types article. This article will cover the following heating system types:
Ground Source Heat Pump
Variable Refrigerant Flow (VRF)
Heating System Types
Gas Boilers produce heat by burning fossil fuel, typically Gas. Heat energy is distributed throughout the building by water and electric pumps are used for the circulation. Gas Boilers are a common and versatile heat source with their main drawback being the the burning of fossil fuels. cove.tool supports Gas Boiler systems with any air system and corresponding independent cooling systems.
Electric Boilers produce heat by electric resistances. Heat energy is distributed throughout the building by water and electric pumps are used for circulation. Electric Boilers are less common than gas currently, however, are just as versatile. The main drawback of electric boilers is the low efficiency of converting electricity directly to heat. cove.tool supports Electric Boiler systems with most air systems and corresponding independent cooling systems.
Electric Resistance produces heat by passing electric currents through resistor elements. Heat is distributed by the power cables themselves the direct point of use as either coils in air handling units (AHU) or elements within spaces such as reheats or electric baseboard elements. Electric resistance heat is the most basic method to produce heat via electricity. Electric Resistance systems are most common in warmer climates where heating requirements are low. The main drawback of electric resistance is the low efficiency of converting electricity directly to heat and safety concerns. cove.tool supports Electric Resistances systems with various air systems and corresponding independent cooling systems. More on Electric Resistance heating on energy.gov
Ground Source Heat Pump
A Ground Source Heat Pump (GSHP) uses the constant temperature of the Earth's crust to exchange heat instead of the air, which temperature varies throughout the day and the year. By utilizing this constant temperature difference the heat pump is able to achieve a higher and more consistent COP than an air source equivalent. Typical GSHP access this constant temperature through boreholes which can range from 100 to 600 feet deep and must be spaced at least 20 feet apart. These boreholes lead to high construction costs that must be offset by energy and cost savings. The heat pump itself can provide heating hot water, chilled water, or both. Like a standard boiler, the heat energy is distributed by water with electric pumps used for circulation. More about GSHP on energy.gov
Air Source Heat Pump
An Air Source Heat Pump (ASHP) uses the outside air to exchange heat with the building. The efficiency of these systems is dependent on the local climate and in some extremely cold climates will not be able to provide heat at all times. These heat pumps are typically located on the roof of a building and may require a large footprint depending on the total load required. Even with these limitations, ASHP is still a great option for electrification as they provide a COP above 1 for heating operation. Like a standard boiler, the heat energy is distributed by water with electric pumps used for circulation. More about ASHP on energy.gov
Variable Refrigerant Flow
Variable Refrigerant Flow (VRF) provides heating and cooling via room units. See this article for details about this unique HVAC solution.
Furnaces are the lowest efficiency option available. Typically these are found in residential or small projects that utilize packaged type equipment. Low installation cost is the primary reason to use a furnace, however with low efficiency (around 80%) and continued to move away from new gas connections they are not recommended.