Today there are many different types of heating systems used to keep homes warm and often, these heating appliances are just one component of a home’s larger HVAC system (heating, ventilation, and cooling).
In combination, this system helps to ensure a comfortable temperature and humidity in the home is maintained, whatever the local climate or time of year.
Although diverse in design and function, the one thing all heating systems do have in common is their ability to harness the thermal energy from their fuel source and release in a way that provides maximum warmth and comfort.
However, the fuels heating systems use, as well as the mechanics behind them are extremely diverse. As a result of this, they all differ in terms of energy efficiency, heat output, heat capacity, installation costs and of course maintenance.
As the name suggests central heating is a specific type of heating system in which the heat is produced in a central location and then circulated to other parts of the property using a distribution system. In the United States, central heat commonly includes gas furnaces, boilers/water tanks, and heat pumps.
In North America, furnaces are the most popular type of central heating system used for home heating. There are many types of furnaces that are categorized by the type of fuel they utilize, this includes gas, electricity, oil, coal and even wood, but natural gas is by far the most common.
As the fuel source and air is ignited within the furnaces combustion chamber, it begins to burn and produce an intense flame. In turn, the heat released from the combustion process is used to heat up a metallic component known as a heat exchanger. Furnace fans then blow cold air through this structure and into the distribution system to deliver the now warm air to the rest of the property.
In terms of energy efficiency, furnaces have seen some substantial improvements in recent years, with newer high-efficiency furnaces achieving more than 90% efficiency. Multiple changes are responsible for these impressive efficiency ratings, including high-static heat exchangers, the use of electronic ignition and vent dampers.
For example, old furnace designs used to release exhaust gases straight out through the chimney or ventilation system, resulting in around 30% heat loss. Yet new models utilize an internal damper that draws a large amount of exhaust gas back into the heat exchanger where it can be re-used.
It achieves this by condensing the water vapor from the exhaust fumes, which releases the heat that can then be put to use. The exhaust fumes are then cool enough to be vented through a plastic pipe.
The following are some of the various common reasons of why a leak may be coming from the top of your water heater:
Also referred to as hydronic heating, water boilers utilize hot water to heat the home, unlike furnaces that use warm air. The most common type of water boiler is natural gas, followed closely by oil, which like furnaces is used to heat a component called the heat exchanger, which in turn heats the water.
The heated water is then delivered to the rest of the house from this central location via a water pump, which pumps the water through copper pipes into radiators or similar structures. As the hot water is transported through the home, the heat is radiated out into the living space and returns back to the boiler to be reheated.
Boiler systems are typically controlled via programmable thermostat, aquastat, and valves that enable the user to change the temperature, timing and flow rate. Features to look out for include limited electrical requirements, and the capacity to provide indirect water heating. In terms of efficiency, high-efficiency models can reach 80%.
Heat pumps are unique in that they provide both heating and cooling as they can essentially operate as a two-way air conditioner. When heating your living space, heat pumps transfer heat from the air outside into your home. In order to cool your home, this process is reversed e.g. heat from inside your home is transferred to the outside.
Heat pumps achieve this with the use of a condenser component (that mimics an evaporator), and a refrigerant (like R-4110A). The condenser can then be switched to apply different levels of pressure to the refrigerant, which in turn determines whether it is in cooling or heating mode.
For example, the condenser can then either place the refrigerant under high pressure resulting in condensation, which releases heat resulting in a warming effect. Or, alternatively, it can place the refrigerant under low pressure, resulting in evaporation, which absorbs heat and results in cooling.
The most common type of heat pump used in the United States is called an Air-source heat pump. These use air from outside as the heat source in winter and heat sink in summer. They are relatively low cost and easy to install.
There are also ground-source heat pumps too, which are less common since they are typically quite expensive and difficult to install. As their name suggests, these ground source heat pumps, get their heat from below the ground. Installation involves boring holes beneath the home or on the surrounding land and installing long copper wires either vertically or horizontally.
As the name implies, direct heat is the type of heat not delivered through a delivery system. Instead, it is released into the living space immediately when switched on and active.
Wood Burning Stoves & Pellet Stoves
Burning firewood can be extremely advantages for those that live in more rural locations with abundant access to firewood. Savings can be even more impressive for individuals who have access to their own land and trees or another cheap supply. Many people find wood stoves appealing due to their warm, homely feel and the energy security they provide.
For instance, if there was a power outage a wood stove would be completely operational. Unfortunately the same can’t be said about the majority of pellet stoves, but they still benefit from the other advantages. Pellet stoves, on the other hand, have lots of automated features including a motorized feeder, so are ideal for those people looking for a lower maintenance alternative.
In recent years, the Environmental Protection Agency has been implementing new rules and regulations on new stoves. This has led to the creation of high-efficiency stoves that are better for the environment and mean you will use less firewood.
Electric Space Heaters
Electric space heaters rarely make financial sense as they are expensive to operate, yet since they are so inexpensive to buy remain a very popular type of heating. In comparison to other types of fuel, it takes a lot of electricity to produce the same heat output. For example, in most cases, a heater that runs off natural gas, oil, and firewood are all cheaper to run in comparison.
Electric space heaters or any other type of electrical resistance heating should only ever be seriously recommended in a few isolated circumstances. For instance, if a person was using temporary accommodation, intermittent use could be seen as reasonable, as the installation of a ventilation and more efficient heating appliance could likely not be justified.
Gas Space Heaters
Gas space heaters come in a wide variety of shapes and sizes including in the form of air blowers and wall-mounted units. They are commonly fueled by propane, natural gas or kerosene and provide a relatively high heat output for zonal heating or the heating of small areas such as single rooms, garages, sheds, and outbuildings.
Gas space heaters remain popular due to their inexpensive cost and portability. Yet their lack of ducting makes them a poor choice for heating medium to large-sized spaces. However, they are certainly useful in a variety of scenarios e.g. where heating a single room or other small space is acceptable.
Gas fireplaces including inserts and traditional masonry style fireplaces remain popular due to their aesthetic appeal. However, they are typically not the most efficient method of home heating, since the majority of the heat produced from the direct combustion of gas is lost up the chimney and into the surrounding masonry.
Exceptions to this rule include gas fireplaces that are well insulated with a firebox, tight-sealed glass door, and chimney dampener. For instance, gas fireplace inserts are much more efficient than standard masonry fireplaces, being able to achieve energy efficiency ratings range from 70 percent to 80 percent.
About the Author
Dave Miller is a HVAC technician with over 10 years in the industry. Dave created HeatTalk with the ambition for it to become a resource for individuals looking for answers, whether they be a layman, student or a professional.