Boilers provide efficient heating for millions of homes in the United States. The residential boiler originated in the late 1700s and has remained an effective way to mitigate winter temperatures ever since. But how do boilers differ from other heating methods, and what are the most important considerations when choosing one for the home? Whether you are getting a new boiler for the first time or replacing your existing one, a look at the key factors of selecting a boiler can help you make the best decision for your household.
What Is a Boiler?
A boiler is a central appliance that produces heat by warming up fluid in a closed vessel or tank. The boiler distributes this heat through a network of pipes to various radiators within the home. In the heating system industry, the two basic types of boilers are steam boilers and hot water boilers. A steam boiler continues to heat until its fluid becomes vapor or steam. In contrast, a hot water boiler keeps its fluid in a perpetually liquid state. An HVAC professional can help you determine whether a steam boiler or a hot water boiler is compatible with the radiators within your home. Both categories of boilers may use various types of fuel sources, including natural gas, propane, electricity, heating oil, or a biodiesel-oil blend. These fuel sources have varying degrees of energy efficiency.
Why Should I Get a New Boiler?
Most homeowners get a new boiler to take advantage of the heating benefits or to replace an existing boiler that has reached the end of its lifespan. Boilers are ideal for heating homes during harsh or drafty winters. These appliances are different from furnaces. For comparison, a furnace works by forcing warm air through the home’s ductwork. A furnace is part of a home’s comprehensive HVAC system and usually shares ductwork with an AC unit for year-round climate control.
In contrast, the sole purpose of a boiler is to provide excellent heating. Boilers provide an even distribution of heat and are helpful for getting through cold seasons. However, they are not as popular for homes in tropical climates that need comprehensive cooling systems instead. Key benefits of boilers include the following:
- Energy efficiency
- Compact design
- Quieter operation
- Better warmth in extreme cold
- Less dust and airborne pollutants
- Sturdy and long-lasting
Boilers are quite durable. According to the U.S. Department of Energy, most boilers have a useful lifespan of 15-20 years. As your boiler ages, however, it may begin to lose its operational efficiency. This can increase the number of maintenance checkups and repairs. If the number of repairs becomes too frequent, it is usually more cost-effective to get a new boiler. Signs that it is time to replace your boiler can include the following:
- Regular breakdowns
- Repairs that exceed the cost of new boiler
- Increased heating bills
- Sudden unusual noises or smells
- Insufficient heating capacity
- Property sale or rental plans
A home services professional can evaluate your appliance and determine whether it is feasible to repair the existing boiler or if you need to install a new one.
What Are the Different Types of Boilers?
In addition to the two main categories of steam boilers and hot water boilers, there are three types or styles of boilers from which to choose. Any type of new boiler you select depends upon the size of your property, the number of home occupants, and your anticipated heating demands. The three primary types of boilers are combi boilers, system boilers, and conventional boilers.
Combi Boilers
A combi boiler is a single, space-efficient heating system that does not require additional tanks or cylinders. Its compact size makes it ideal for smaller properties, and the minimal amount of pipework needed also makes this choice economical. While it can deliver instant heating and hot water on demand, a combi boiler takes this hot water directly from the mainline. This means that the property should have consistently high water pressure. Combi boilers deliver hot water mainly to one tap at a time, making them less ideal for larger properties.
System Boilers
A system boiler is a solid choice for homes with two or more bathrooms and a high demand for heating and hot water. This boiler uses a hot water cylinder and also uses your home mainline.
Conventional Boilers
Conventional boilers are ideal for the largest homes. These boilers are the most traditional type and are also called open-vent boilers, heat-only boilers, or regular boilers. This kind of boiler has a separate cylinder for hot water as well as a cold-water storage tank. Conventional boilers work in homes with multiple floors or levels and will continue to work even if the water pressure is low.
What Are the Energy Efficiency Ratings for Boilers?
The heating and cooling industry ranks boilers with an annual fuel utilization efficiency (AFUE) score. This score indicates the percentage of energy the boiler can convert into heat. Federal regulations require all new boilers to have an AFUE score of at least 80%. Any old pre-existing boilers may have an AFUE rating of 56-70%. High-efficiency and ENERGY STAR-certified boilers can have AFUE ratings of up to 98.5%. These boilers use less power or fuel and may save on energy costs in the long run. A professional technician can help provide guidance on the best boiler for your household.
What Are the Key Features of Boilers?
There are a few additional features to understand before choosing a boiler. Such factors include whether the boiler is a condensing or non-condensing unit and whether it has sealed or non-sealed combustion.
Condensing vs. Non-Condensing Units
All boilers are either condensing or non-condensing units. In the past, non-condensing boilers were the only types available. Non-condensing boilers expel extremely hot exhaust gases of up to 400 degrees Fahrenheit out of the unit’s ventilation chimney, resulting in lost heat energy and reduced efficiency. In contrast, newer condensing boilers can concentrate this water vapor produced in the heating process. According to the Department of Energy, this condensing mechanism can make the unit 10-12% more efficient.
Sealed vs. Non-Sealed Combustion
Boilers conduct either sealed or non-sealed combustion. Most experts prefer sealed units since they are more energy efficient and lower the risk of introducing carbon monoxide (CO) poisoning into your home. Instead of releasing fumes into your house, a sealed combustion unit is closed off and draws air through a pipe that connects it to the outside.
How Do I Choose the Best Boiler?
All factors considered, many homeowners try to select condensing, sealed-combustion boilers that offer a high degree of energy efficiency. Choosing from among combi, system, or conventional boilers depends on the size and number of occupants of your home. For example, small apartments or one-bedroom houses are compatible with the combi boiler type, but multi-level homes are more compatible with conventional boilers instead. Other factors to consider include actual boiler size, fuel or energy source, and existing flue system.
Boiler Size
In addition to boiler type, the industry measures actual boiler size in kilowatts (kW). If the boiler is undersized, it will not work efficiently. But if it is oversized, it could end up costing more to fuel your home. A professional technician can help you determine the right size. For example, small houses with one or two bedrooms can use a boiler that is 24-27 kW, but a large house with over four bedrooms would need a boiler that is 35-42 kW.
Flue System
Flue systems have varying configurations. The boiler you choose must be compatible with the existing flue system in your home. A home services technician can help you make the right choice.
Fuel or Energy Source
Different boilers use various types of fuel. If you have a gas connection, you will need a compatible gas boiler. A technician may also need to install or repair gas connections and safeguard against potential gas leaks. Otherwise, you would need a compatible-fuel boiler or one that uses a power source such as electricity.
Get Help From the Experts Today
A boiler is a top heating solution for making it through cold and bitter winters. Davis & Green provides boiler services for homes in Richmond, VA and surrounding areas. We can answer any questions you have about boiler installation, maintenance, or repairs. In addition to boilers, we can help with gas and electric furnaces or heat pumps. Our technicians offer whole-home rewiring, generator testing, and more. Contact Davis & Green today for all heating needs.
