There are two staple heating systems installed in our households—the radiator or hydronic heating system (boilers) and the forced-air system (furnace). Boilers utilize water to produce heat, while furnaces make use of the air to spread out heat through your house.
A radiator or hydronic heating system typically uses gas, propane, or oil for fuel. In this system, a boiler will heat up the water. This boiled water is then distributed to different pipes and into radiators by the help of zone valves or circulator pumps. When the water cools down, it will be circulated back to the hot water boiler to be reheated.
In contrast, a forced-air system consists of a network of ducts that aids in filtering, heating, and circulating air throughout your house. In this system, the ductwork draws in the cold air and delivers it to the furnace to heat the air up. Like a boiler, a furnace also used electricity, natural gas, or heating oil for fuel.
Installing a forced-air system is a lot more inexpensive than a hot water boiler system. Considering the comparable size and efficiency, the boiler itself and its installation tend to be 2-3 times more costly than a home furnace.
For example, here’s a quick product list guide:
Average gas furnace – 600-1,000 USD
Average gas boiler – 1,500+ USD
Average oil furnace – 1,000-1,600 USD
Average oil boiler – 2,000-5,000 USD
There are other forced-air systems like electric furnaces that cost under 500 USD, but they’re not as efficient as consumers expect them to be. Moreover, when it comes to replacement costs, installing a boiler is still a lot more expensive.
The following is a breakdown of replacement and installment costs you can use:
Average gas furnace replacement cost – 1,200-2,500 USD
Average oil furnace replacement cost – 4,000-5,000 USD
Average new oil boiler installation cost – 3,000-5,000 USD
Average new gas boiler installation cost – 3,500-8,000 USD
Notice that the replacement costs of forced-air systems (furnace) above are lower than the installation of hot water boilers. Also, these prices are estimates for straightforward installments, which don’t require any additional taxing works. However, if you’re not into owning systems, there are boiler rentals that are available online, too.
One of the simplest ways to measure the energy efficiency of most heating systems is through combustion efficiency. It evaluates a system’s efficiency while it is functioning. Specifically, it measures the total amount of useful heat generated per unit (combustion) of fuel (input energy).
In the United States, the energy efficiency of both furnace and boiler is measured by annual fuel utilization efficiency (AFUE). As mandated by the US government, any heating system should have a medium rate AFUE, or at least 78% AFUE rating.
Here’s a round-up of system comparisons, according to efficiency and AFUE ratings:
56-70% – Low
80-83% – Medium
90-98.5% – High
The age of your heating system is another crucial factor to consider when measuring its energy efficiency. Older furnaces or boilers have around 50-65% AFUE rating, as opposed to up to date systems that can be in the 98.5% range.
An energy-efficient heating system utilizes a smaller amount of fuel, which, in turn, brings down carbon dioxide emission levels. This also consequently cuts down pollution output in half. What’s more, since you’re using less fuel to heat at home, it allows you to save money on your monthly energy bills.
Both energy heating systems are about the same, so long as they’re new and highly-efficient models. Recently made furnaces and boilers with advanced features boast over 95% (or so) energy efficiency. If you’re using an older system, it’s recommended to retrofit it to make it more energy-efficient.
The forced-air system, however, can potentially be less efficient, especially in very cold areas. The lower the temperature of a place is, the higher the need for fuel to heat, which eventually becomes more costly.
It also costs more when duct systems are placed in a partially conditioned or unconditioned space, like an attic, basement, or garage. There’s a tendency that the heat generated from the furnace can break free through the duct system. This heat loss, which can be as high as 35%, significantly heightens your heating bills.
On the other hand, when using hydronic systems, you wouldn’t encounter the need for more burning materials even if it’s freezing cold. You only need to have water when using boilers. Heat loss doesn’t take place, too, since you’re not using duct systems. Even so, it’s advised to apply to add zone control on your hot-water system.
In a nutshell, both systems are energy-efficient. To save more money in the future, opt for high-efficiency models of boilers or furnaces. However, when it comes to installation costs, boilers can be more expensive. Either way, it’s advisable to install programmable thermostats.