Most people in Newmarket have a single-stage furnace. This has been the most common option in most homes. But are there any benefits that come with having a furnace that has multi-stage operation? What is a true modulating furnace?
When your furnace has a multi-stage operation, it will have a gas valve that regulates the flow of gas into the burner and the heat exchanger. This is unlike a single-stage operation where gas flows at full 100% capacity whenever the furnace is turned on even to increase the temperatures by a single degree.
With a 2-stage operation furnace that has a thermostat, it starts on the lower heating stage, which is about 60% of full natural gas flow rate capacity. If the operation doesn’t reach the thermostat set-point in about 10 to 16 minutes, the regulator opens to allow full gas flow. The same concept applies in a 3-stage furnace, only that the furnace has three settings: one at 40%, another at 60% and then 100%. As a result of this, the 3-stage furnace can be described as modulating furnaces. They are, however, not true modulating furnaces.
For a true modulating furnace, there are over 40 to 50 settings on the gas valves. These have smaller increments from 30 to 100% opening. A good example of such is the Carrier’s INFINITY 98. This is also the only furnace you will find that can modulate down.
To better understand the difference between all three furnace options, we need to look at a scenario. When using a single-stage furnace and the temperature reading is at 20C, and the furnace is turned off, and you feel cold, you go to the thermostat and set it at 21C. The furnace will light up, and because you have a single-stage furnace, the gas valve will open fully. The furnace will thus be operating at full capacity to raise the temperatures by 1C. It will start getting hot when this happens, and the thermostat may read 23C after the furnace turns off. It will get cooler as the temperatures drop to 21C. The furnace will kick in again to maintain the temperatures at above 21C. The temperature fluctuations are caused by the lack of control over the flow of gas.
If you have a single-stage furnace, you have definitely dealt with these temperature fluctuations. However, using a multi-stage furnace solves this issue by controlling temperature changes with a gradual change.
A single-stage furnace offers less control and thus produces temperature fluctuations. When turned on, the furnace will operate at full capacity even if only a single degree needs to be added. Multi-stage operation, on the other hand, allows you to increase temperatures gradually. The more heating stages a furnace has, the more control you will have in achieving desired temperatures.
With this information in mind, there are two key benefits offered by a multi-stage furnace:
- Tighter control on temperature. This results in gradual temperature changes and also eliminates temperature fluctuations.
- The furnace’s operation is much quieter. This is because the furnace doesn’t have to run at full capacity to maintain the desired temperature. Lower gas flow rate is linked to lower sound because increased pressure inflow is accompanied by vibrations and thus more noise.
Get in touch with us to ask about the technology all Carrier multi-stage furnaces have that ensure tighter temperature control. These furnaces use patented technology known as adaptive logic.
Common Misconception About the Number of Heating Stages and Energy Saving
It is good to note that having more furnace stages doesn’t affect the efficiency and rate of gas consumption. You will still need the same amount of energy to heat the house. When operating at higher stages, it uses more gas within a shorter period. When on the lower stage, the furnace will use the same amount of energy only for a longer period. At the end of the day, the fuel consumption on a single-stage and multi-stage furnace will be the same.