Selecting a new furnace for your home can seem like a pretty overwhelming process. While it is an important decision and many factors have to be considered, overall it’s simply a matter of following the right steps to make the best, most informed choice for your home and family.
Determine the proper size furnace for your home
In order to ensure that you’re heating your home comfortably and without wasting energy or money, it’s essential that your furnace is the right size. Furnace sizes are based on their input rating, which is expressed as BTU/hr, or British Thermal Units per hour. Determining what input rating your home requires is accomplished through a process called load calculation, which is performed by an HVAC professional. Common gas furnace input ratings for homes range from 40 000 to 120 000 BTU/hr.
Select the level of furnace efficiency that is best for your needs and budget
Not only do furnaces come in a range of sizes, they also have different efficiencies. A furnace’s efficiency is determined by how much heat output a unit is able to create relative to how much gas is inputted. A furnace’s efficiency rating is known as its AFUE, or annual fuel utilization efficiency. A unit’s AFUE is expressed as a percentage. To give an example of how AFUE works, if a furnace has an AFUE of 90%, then for every 100 BTUs of natural gas input, the furnace creates 90 BTUs of usable heat. High-efficiency furnaces generally have an AFUE of between 90 and 98%. High-efficiency furnaces are also known as condensing furnaces. These furnaces come equipped with two heat exchangers and a sealed combustion area and are able to extract so much heat from the combustion process that they condense water vapor as they work, hence the name condensing furnaces. High-efficiency furnaces may come with a slightly higher price tag, but they offer significant energy bill savings over lower-efficiency units because they require less gas input. Since we all know what fuel costs are these days, the benefits of a high-efficiency furnace are obvious. Mid-efficiency units have an AFUE of about 80%. These mid-efficiency models are known as non-condensing models, and have only one heat exchanger instead of the condensing models’ two. These units require metal piping to direct combustion byproducts out of the home. Mid-efficiency furnaces have a lower upfront cost, but will undoubtedly make for higher energy bills.
Decide which furnace options you would like
Every home is different and has unique heating needs, which is why furnaces come with a variety of features. Popular features include a variable speed blower motor. A variable speed blower motor is able to more precisely control the flow of heated air throughout the home. Not only are variable speed blower motors typically quieter than a standard blower motor, but they also consume less electricity and enable you to control the temperature and comfort levels in different areas of your home. Another type of furnace you may want to consider is a two-stage furnace, which has two separate gas input rates. The first stage of a two-stage furnace which operates at a lower level and burns less gas, yet heats effectively enough to meet the heating demands of your home on most days. On colder days, the furnace can increase its output by transitioning to the second stage, which burns more gas and creates more heat. An obvious benefit of a two-stage furnace is its efficiency. A two-stage furnace also provides more even heating because it heats continuously at a lower rate instead of stopping and starting at full blast, like single stage furnaces. One of the most advanced furnace options is what’s called a modulating gas furnace. These models generally combine a variable speed blower with a modulating gas valve. Using this technology, the furnace can regulate the amount of fuel burned according to your thermostat setting. Not only will this save fuel and money, but it will maintain your home’s temperature to within 0.5 degrees of your thermostat’s set point. It can be difficult to know which furnace options or features are best, but an HVAC professional can assess your living space and help guide you towards the most efficient and cost-effective selection for your home.
Assess the installation
Once the proper furnace has been selected, all that’s left is to have it installed. Professional furnace installers will be happy to show you around the work they’ve completed and allow you to inspect based on this checklist.
- Check that the air filter is accessible so it can easily be changed.
- Make sure all duct connections at the furnace are sealed to prevent air leakage. In spite of its name, duct tape should not be used for this sealing.
- Does the unit have rubber isolation pads underneath it? This will minimize noise during the furnace’s operation.
- Furthermore, if the unit is located in a basement, it should be on blocks which elevate it at least four inches off the floor.
- You should be able to locate an electrical disconnect device within three feet of the unit.
- When it comes to something as intricate and all-important as a furnace, you want installers who pay attention to detail. Is there any trash or debris left in the installation site?
- A new high-efficiency furnace requires a new digital thermostat. Has that thermostat also been installed?
- To ensure that it works correctly, run the system through a normal cycle. Listen closely for popping noises from the ducts when the fan starts or stops. While some noise is normal and to be expected, popping noises are not.
- The vent pipes should be as short as possible.
- The vent pipes should also be sloped to the furnace at a rate of ¼ inch per four feet.
- There needs to be a shutoff valve for the gas or oil beside the furnace. Is it readily accessible? You should not have to remove an access panel to get to the shutoff valve.