HVAC installer

Boiler Installation: Types, Cost, Tank Sizes, Efficiency & More

When you’re looking to install a boiler, there are a lot of different things you need to understand, if you haven’t already chosen the type that you are looking to have installed. In this extensive article, we’ll give you a much better understanding of what the job of a boiler is, which systems you should choose between, as well as help you choose among the many different types of fuel which will impact which model you will be choosing.

A boiler is a closed system in which a liquid is heated up, and in the United States it is normally called a furnace if the intention is not to boil the fluid. When either the heated water or steam leaves the boiler, it will be used for the intended purpose which may for example be heating using radiators. Boilers are in fact very versatile heating systems.

The history of the boiler can be visited right here.

Water heater versus a boiler

a picture of a water heater

A water heater and a boiler work slightly different ways, although both of them basically work by heating up water. When the water is heated in the water heater, it will traditionally be stored in a tank until it is used in the different. Although there are different types, some that don’t have a tank, they traditionally work very much the same way anyway.

Boilers are generally what is being used for commercial applications due to their increased capacity. They can not only heat water, but they can even heat it so much that it turns into steam with the ability to use it for a range of different things including heating through a central heating system.

What size boiler do we need?

Some people choose to compare a boiler to the engine that sits inside a car. It will be producing the heat that is traveling around the home, but when it comes to choosing the right size, you need to know that an oversized boiler will cost you money on your electric bill, while one that is too small will not be able to generate the amount of heat needed for your house.

For that matter, the size you will need will not only depend on the size of your home, but also the severity of the winters in your area, as well as how well your home is insulated. In the ideal situation you want the boiler to just be able to produce sufficient amounts of heat on the coldest days you could possibly be expecting, although this may be accurately estimate. A lot of the boilers that are currently in homes, have a lot more capacity than that specific house needs, but as energy calculations have gotten more accurate, it is now easier to better discover the correct one with energy conservation in mind.

As a boiler can only produce so much steam, it means that the more radiators you plan on installing, the larger the whole system will need to be, and the more it will cost. A boiler is only one of four parts in the heating system, with the others being the piping with the pumps and valves, the radiators as well as the control system, which traditionally means a thermostat where you can set the temperature.

While you obviously do not want to go freezing in the winter, remember that an oversized boiler will simply add to your bill in the end. As pointed out by Consumer Reports, you should consider proper insulation in attic and walls, adding weather stripping and caulk in areas that may be especially leaky, cleaning your chimney, and set the ceiling fans to spin clockwise allowing them to keep heat down that would otherwise rise. If you have very old windows in your home, you could also consider installing new ones.

Factors to consider

There are some different factors for you to consider before choosing which one to get. Northern Energy and eComfort have gathered a lot of those different factors.

  • The fuel utilization efficiency rating.

Newer units are naturally more efficient than older units, but if you live in a place where the type of fuel that the boiler is using is especially expensive, you will need to be especially sure that your unit’s efficiency is high. The fuel utilization efficiency rating helps tell you how good the unit is at turning fuel into actual heat.

  • Requirements for venting for the different units.

When looking at the different boilers, they will have different requirements for venting. You need to make sure that the venting options where you plan on installing the unit fits with the requirements. Research whether the unit vents through the chimney or the wall.

  • The type of fuel.

Boilers use different kinds of fuel, and if you are hoping to get one that uses gas, then it very much helps to be connected to a gas network. Different types of fuel will also have varying degrees of efficiency, and it’s worth researching too in this whole process.

  • Size

This should come to you as no surprise following our previous section that talked extensively about this very issue. Consider watching this video on the topic too.

  • Climate

If you’re in a region that does not only simply get cold but also a lot of heat, you may be better off looking into having an HVAC system installed instead, as a boiler will only be able to heat and not cool.

  • BTUs

A fancy measure for the total amount of energy required. According to Reference, hot climates require just 20 BTUs per square foot, with the number increasing to 50 BTUs per square foot for cold weather.

Types of boilers

When people speak of the different types of boilers, they generally either speak of fire-tube or water-tube, and the type of fuel that is being used inside the boiler is then another aspect for you to consider.

Additionally, they are categorized into four categories: hot water boiler, steam boiler, high-pressure or low-pressure. We’ll walk you through all the differences for you to get a better understanding.

Different boilers are built to be able to withstand different amounts of pressure, and the MAWP literally stands for the Maximum Allowable Working Pressure. It is measured in pounds per square inch, also known as PSI, while the measure being used to express this is called psig.

While your choice between high or low-pressure, what you will mainly be looking at is the intended use of the boiler, as getting a high-pressure option may be excessive if the job can be done successfully by a low-pressure system.

High-pressure

High-pressure boilers are the ones where steam or other vapor is generated at more than 15 psig pressure, or where water is heated to more than 250°F.

list of high pressure boilers
Picture from Quora

Given the amount of pressure inside these machines, especially the commercial ones, the people caring for them need to use special caution to avoid possibly getting injured, as hot pressurized steam presents significant threats.

The high pressure boilers both have different advantages and disadvantages you should know about, including using less floor space and being economical. All the different parts are also heated evenly, thereby minimizing the risk of overheating. They do have the risk of overheating with an insufficient water flow, and it only works using either liquid or gaseous fuels.

Low-pressure

As opposed to high-pressure boilers, low-pressure ones, produce steam at less than 15 psig.

Fire-tube

In a fire-tube boiler, as the name says, the gases will pass through tubes, and water will be on the outside of the tubes getting heated by the warm gases. It’s a system that is very simply built but on the flip side the system will take a long time to raise the steam pressure, as the system has a large amount of water that needs to be heated before it starts turning water into steam. Check out this video to get a more thorough understanding of the concept.

The fire-tube design is not only older but also a much weaker structure and is not commonly used for high-pressure boilers as a consequence.

Fire tube boiler in a locomotive
Picture from Wikipedia

Water-tube

In a water-tube boiler, on the other hand, it is the water traveling through the tubes where as the combustion gases are on the outside. With this design, they can more quickly both start generating steam, generate more of it as well as adjust to the amount of steam needing to be produced.

This image shows you how a water-tube works.

water-tube boiler
Picture from Wikipedia

Since there is not a large amount of water in the system, the risk of a large catastrophic failure is not nearly as big.

Materials

Types of fuel

There are a range of different models of boilers that will each burn different types of fuel. Consider the type of fuel you wish to use and that the model you have been looking at is the appropriate one for you. For instance, energylogic has made a boiler capable of using waste oil, meaning it can use everything from 5 to 90 weight.

Wood

If you live near a forest and have easy access to firewood you can even cut yourself, this type of fuel may be what you are looking for, since it can be a very affordable option. A good model will also be able to automatically lower the amount of air in-flow, which in turn means that the wood will end up burning for a longer time. The disadvantage on the other hand is, if you don’t have easy access to firewood, this may not be the option you should most seriously consider.

You must also know that not only is the wood bulky, but you will need to manually go out and add it to the boiler whenever it is needed, which could be as often as every day. An outdoor wooden boiler will not take up any living space either, nor will it be a fire hazard. It also does not have any major ecological impact since the wood you are burning is a renewable energy source.

Electric boiler

electric boiler

An electric boiler has other benefits as they can be placed almost anywhere on your property, not needing a separate chimney, nor do they need a gas pipe run to them. They lose very little heat, and their efficiency is therefore almost 100%.

A disadvantage is that the electricity may on the other hand be more expensive than using for example gas, and you owe yourself to find out the difference in operating cost of the two different systems, and that an efficient system might be efficient, it could still run up some serious bills.

An electric boiler may cost $1,500 without the cost of having it installed.

Oil

Oil is a very good, efficient option to go with for fuel. In fact, it is so good that the Department of Ecology came out with a study that says oil is 16% more efficient at heating than natural gas. Modern oil boilers will also having efficiencies in the 85-95% range, which means your heating dollars are spent very carefully, and not a lot goes to waste in the process of heating up your home, and it’s a very safe option to go with as well as being compact in size.

An oil boiler will cost between $1,959 and $3,180 without the cost of having it installed.

Natural gas

Natural gas is another popular type of fuel for boilers that is extremely popular, and as long as you’re connected to the gas supply, there won’t be much you will need to do. An advantage to this system is the fact that you don’t need a big storage tank, which you’d need for oil, for example. During combustion, gas also does not create harmful gases and fumes. As it doesn’t generate soot and dust, it also means that it will last long, although the initial cost of the installation is higher than other solutions, and a gas hookup is obviously a requirement. Popular Mechanics also made this questionnaire to help you decide between your options.

A natural gas boiler may cost between $1,700 and $3,100, which does not include cost of installation.

Coal

A boiler that uses coal has some advantages to it, as well as disadvantages. There’s an abundance of coal, which means there’s still coal for another 300 years. The disadvantage to coal is it emits a lot of green house gases, as you’re using something that has been dug down in the earth for thousands of years, and the mining of coal is not exactly a pretty one, leaving the coal mined areas looking bad after it’s been extracted. While coal is widely available, its production also includes a lot of harmful byproducts, like mercury, sulfur dioxide, selenium, and arsenic.

Biomass

Biomass, to start off with, is material derived from living organisms, which can be plants for example. Getting a biomass boiler is considered an environmentally friendly choice since the fuel has a low environmental impact. If you’re very socially conscious, this might be the option you have been looking for. With bio mass being considered carbon neutral, you can sleep well at night, although you might want to consider if this is an economical option in the place you live. This option also comes with  the downside that it will be needing more maintenance than other options will.

Pellets

pellets that are burning

As with wood, this is a very environmentally friendly option to go with and can in fact be fed automatically into the boiler according to Green Match. At the same time, as these pellets are usually produced locally, this will be good for the local economy as a consequence. Pellet distribution also costs less than that of wood chips, and efficiency rating of about 80%. As pellets are bulkier than oil, you will also need more storage space to keep the pellets, although in terms of cost per unit of energy, heating oil and propane are more expensive solutions.

It will also be sweet to hear that there are many government incentive programs to lower the cost of installing a wooden pellet boiler in your home.

Cost of Installing a Boiler

The typical cost range for installing a boiler will be between  $3,300 and $7,500, depending on you getting the best quotes from contractors. What you need to know is that by getting a high-efficiency model, you may be spending a little more to start off with, but this in turn will turn into cost savings over time.

When you’re replacing a boiler, here is why there’s significant cost to installing a new one.

  • The new tank will need to be tested when it comes to potential leaks or other problems to make sure everything is working correctly.
  • Replacing the tank will also add to the cost.
  • Soil tests must be done to ensure that the previous tank did not have any nasty leaks in the ground, and if a cleanup is necessary, this can add $2,000 to $10,000 to the cost of the endeavor.

Boiler Manufacturers

Here’s a list of boiler manufacturers that have certified Energy Star models for you to choose between. This list was originally posted on House Energy. If you have any additions feel free to send us a message so we can add it to the list.