If you have an old furnace or one that’s in disrepair, then you are likely looking for a new high-efficiency furnace that is far superior the units of yesteryear.
In fact, new gas and electric furnaces are not only more efficient but provide cleaner air than ever before and are much easier and cheaper to maintain and repair.
What is a Furnace?
Whether you utilize a gas, electric or oil furnace they all work on the same principle – forced air heating. The furnace generates heat, which is then circulated into the air via fans that transport the hot air through ductwork in the property and through the air vents.
Types of Furnaces:
Gas Furnaces & Propane Furnaces – These operate using a pilot light which ignites a collection of burners within a combustion box. The heat produced through this process is then fed into a heat exchanger, where the heat warms the air to the exact temperature determined by the thermostat settings. The hot air is then transported to your property by the blowers.
The main benefit of a gas furnace is that they tend to have a greater heat payoff to energy input ratio, meaning they are cheaper to run than those that utilize other types of fuel. However, installing a gas furnace initially can be quite an investment as you will require a professional installation and connecting to the main gas supply.
Propane furnaces may be a viable alternative depending on your location, you would need to compare local suppliers with natural gas in order to determine this. Although some people prefer not to utilize propane canisters due to risks associated with storing and using propane gas canisters.
Electric Furnaces – These furnaces are very similar to natural gas furnaces, except instead of a pilot light, an electrically powered ignition generates the heat. The heat, in turn, reaches a heat exchanger consisting of a series of metallic coils. Similar to combustion, the electric current causes the air to warm ready for the blowers to circulate it through the building.
Electric furnaces have the advantage of typically being cheaper than gas, oil and propane units; however, they have a low heat output to energy ratio in comparison to other types of fuel.
Furnaces Vs Boiler – Which one is Best?
Boilers, tanked or tankless water heaters can utilize the same types of fuel that furnaces can – electricity, gas, and oil to produce heat. The key contrast between the two appliances is that boilers use water to transfer heat, while furnaces use air. The furnace uses blowers to transport warm hair throughout the property as a means of heating via ductwork that typically doubles up for use with air conditioning during the summer months too.
The latest water tanks don’t require as much energy input as older storage water tanks. The hot water they produce is transported throughout the home using radiators. A lot of people prefer water tanks since furnaces require ductwork. In addition, water tanks tend to produce a more consistent type of heat that isn’t dry – a common complaint of hot air heating.
Other benefits of water heating tanks include their near silent operation, which is generally more tolerable than furnaces. Since they don’t transfer large amounts of hot throughout your home like furnaces, people don’t often complain about allergens or dust particles being blown around their homes, a terrible situation for those with allergies. You also have more control with boilers, as they allow you to set the temperature of each radiator, meaning you can save money and only heat the rooms you actually use.
So why doesn’t everyone just use water tanks? The issue is that many older homes already have pre-built furnace ductwork, so for many, it makes more sense for them to simply update their existing furnace. This is often more cost-effective than investing in an expensive boiler and all of the required pipework and radiators. However, for those individuals with the budget, greater efficiency and indoor air quality can be attained with a boiler.
How to Choose a Furnace – 4 Factors to Consider:
When on the market for a new furnace there are 4 main features to be aware of – efficiency, brand, performance, and size.
#1. Furnace Efficiency Rating
The efficiency basically measures the amount of energy that ends up heating your home, rather than being wasted in other ways, for instance, thermal energy lost via exhaust fumes. The metric used to determine this is named the Annual Fuel Utilization Efficiency (AFUE) and it’s a measurement of how much fuel your furnace uses that is transferred straight into heat.
For example, a furnace with an AFUE rating of 90% simply means that 90% of the energy used goes onto heat your home, while 10% is lost in other ways, namely exhaust fumes. Today, it’s common to see furnaces with 80% and 90% efficiency ratings. In order to ensure the energy you use ends up being translated to heat always try to choose a furnace with a high AFUE value.
#2. Furnace Performance
Single Stage Furnace – These are furnaces that have two settings – it will operate at full capacity until it reaches the temperature set by your thermostat, after which it will go to the lower setting. This can result in temperature fluctuations and uneven temperatures throughout the property.
Two Stage Furnaces – The heat source or burner in a two stage furnace is able to operate in two different settings, essentially modulating the temperature. For instance, it may burn at 40% capacity or 100% capacity. Two-stage units tend to offer a quieter operation and more even heat distribution since rather than cycles from intense heat and back again; the heat output is more balanced.
Modulating Furnaces – These are the best units in terms of providing even, comfortable heating, instead of rapidly changing their operating temperature, they operate in specific windows. For example, some units operate at 50% capacity and increase it by 5% as the temperature begins to wane – as monitored by your thermostat.
Which is right for you? There’s no doubt that modulating furnaces provide the greatest efficiency ratings, with some achieving around 98%. However, they re expensive in comparison to single and two-stage furnaces, for that reason, you should only consider investing in one if you intend to stay in your property for at least 5 years. This is the amount of time it will take to recuperate the costs and make savings on your heating bills.
#3. Furnace Sizing
Perhaps the most important factor in selecting your furnace is choosing a furnace that is the right size for your property. Using a furnace that is too large can result in uncomfortable temperatures and a sheer waste of energy when you could be heating your home with a smaller model adequately without spending as much on energy. Equally, if your furnace is too small it will never perform its intended goal i.e. heating your home adequately.
When selecting a new furnace many people say to opt for one that is similar or the same size as your old one. However, sometimes this general rule isn’t appropriate:
If your home has since been extended or insulated, you may find the exact size you need has changed due to your heating demands increasing or decreasing.
If you opt for high-efficiency furnace then it’s very likely you won’t need it to be as large as your former one.
Furnace Installation Costs
What is the cost to install a new furnace? This largely depends on the current state of your ductwork and the overall condition of pre-existing infrastructure. Here is a general breakdown of the costs involved:
Initial Furnace Installation – This includes removing your old furnace and making use of the already existing exhaust vent. Typically, the price increases depending on the size of your furnace, current state of your vents and your ductwork. A ballpark figure is anywhere from $1,000 – $2,000, but of course, this can vary tremendously.
Plenum Installation – If your planum is old, needs replacing or your furnace is larger than the one you previously owned then you are going to need to replace it.
Ductwork Repairs – If your ductwork is particular old it’s likely to have holes and leaks that lead to energy wastage. So, in order to ensure your new furnace runs as designed, repairing ductwork will cost around $3-$5 per foot of ductwork.
Thermostat – The type of thermostat you require is largely dictated by the precise model and type of furnace you are using. So if you are utilizing a two-stage furnace instead of a far older model, you are likely to need a thermostat designed especially for it. The latest thermostats are also digital and far superior to manual models.
They allow you to select a precise temperature for certain times of the day and enable you to control and keep tabs on your energy use. The price of a new thermostat can vary tremendously, ranging from $100 to $500 depending on the brand and features you choose.
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.