how long does wood stove take to heat up

How long does a Wood Stove take to heat up?

How long does a wood stove take to heat up? To answer this question, I could measure just the heat-up time of my own wood stove for you and give you the numbers. However, that is not the best way to get accurate numbers. Your home is different than mine and therefore your numbers will vary. To find accurate numbers I have collected stove heat-up times from various people around the web and compiled them in this article.

Quick answer: A wood stove takes an hour to heat your home by 5-10F. It takes approximately 3-6 hours depending on the house and insulation to reach the final temperature. If your wood stove is your primary heat source, you should kindle the fire at least 3 hours before you need a comfortable temperature. But if your wood stove is supplementary heat, you can kindle it 1 hour before you need it and be comfortable. Depending on the outside temperature the final temperature is usually around 65F up to 75F.

If you are still interested, how I got to these numbers, keep on reading.

How fast do wood stoves heat up?

To find out how fast (or slow) wood stoves heat up I looked up the heat-up times of stoves of various people online. I found the best data from a discussion on the heating-related hearth forum in a discussion of how long it takes to warm up the house. Of course, different people reported different numbers.

Here’s the data I found. The heat-up speeds (in Fahrenheit per hour) of different houses that use wood stoves are

  • 5F per hour
  • 10F per hour (reported by the same guy, but regarding a different house)
  • 6F per hour
  • 10F per hour
  • up to 20F per hour

As you can see, there’s a broad range from 5F per hour up to 20F an hour. The higher the number, the faster the home heats up.

Of course, the temperatures don’t rise like this infinitely. The heat-up rates listed are first-hour heating rates. They represent the rise in temperature within the first hour after lighting a wood stove. In the proceeding hours, the heat-up rate drops and eventually comes to a halt. This effect is called saturation. The temperature can’t increase after reaching a certain point.

The reason for saturation is that the warmer your house gets, the more heat it will lose through insulation. At a certain point, the heat energy generated by the stove equals the heat energy leaving the house and the temperature can’t increase anymore.

If you want to increase the heating rate or the final temperature to be reached, you have to input more energy by burning more wood.

When to kindle the fire?

Personal philosophy: The time to light the fire should depend on how much you depend on the wood stove to provide you with heat. Is your wood stove your only source of heat? Then light it well in advance before you need it. For example, if you leave the house for work you should light the fire such that when you arrive home, your home is already well heated.

However, if your primary heat source is not the wood stove (for example a central oil heating system), then you do not depend on the wood stove heat. You can then light the fire 1 hour before you need comfortable temperatures. This could be the case if you want a comfortable evening in front of the TV but your home is already heated to a base temperature by your primary heat source.

Wood stove heat-up time factors

The time it takes for a wood stove to heat your home depends on several factors. In the first section, you saw the various temperature increase rates of different people. The rates range from 5F to 20F per hour. Where does this difference come from?

In the following sections, we are looking at the factors that determine how fast your home heats up.

The size of your home

One of the biggest factors is the size of your home. Small houses heat up a lot faster than big houses. Similarly, small saunas heat up faster. And small pots of water boil faster than big ones.

You can increase the time your wood stove needs to heat up, by reducing the effective area to be heated. This is as simple as closing your living room door. With an open door, the effective heating area is your living room plus all rooms connected to it. With a closed door, the effective heating area is just the area of your living room.

Therefore, determine whether you want to heat your whole house or just your living room. You can control where the heat goes by opening and closing the doors and guiding the heat. More often than not you want a warm living room and cool bedrooms. So, closed doors are the best solution.

Outside temperature

The colder it is outside, the greater the heat-up rate of your wood stove. What? Yes! Cold homes increase in temperature much quicker than warm homes. The reason is that they are in an earlier stage of the temperature saturation curve. However, for the same reason, cold homes take longer to reach the final temperature. The colder it is outside, the earlier you should kindle the fire.

Insulation

“We have a poorly insulated house. [Our] wood stove heats the first floor to about 70[F] in a couple of hours.”

mfglickman on hearth.com

Obviously, the heat-up time of a house using a wood stove depends heavily on the insulation. The better insulated a house is, the more heat it retains inside its walls. Poorly insulated homes lose lots of heat energy and therefore need more time to heat up as well as more wood to burn.

Small side fact: Most of the heat is lost through the roof. If your attic is not insulated properly, your home will lose heat. Even if the walls are well insulated.

Insulation is a driving force for home heating. Aside from the source of heat itself, it is the main factor determining how much effort (time, money, energy) you have to put into heating. Upgrading your home’s insulation is oftentimes worth it and will save you money in the long run. And, of course, your wood stove will heat well-insulated walls a lot quicker than poorly insulated walls.

Structure of the house

One user in a heating forum reports living in a house, where half of the house is old and the other half is new

“With our old 40,000 BTU gas insert and the fan on high, I could run it all evening and barely see a change of 2 – 3 degrees after 4 – 6 hours. […] In the newer half, we can drive the temperature from 62F up to 70F in a little over an hour.”

Ashful on hearth.com

Oftentimes, this goes hand in hand with insulation. While insulation determines how much “heat penetrates the walls”, the structure of your home determines “where the warm air goes”. Big, open rooms take longer to heat up than small rooms.

If you have an open fireplace in your home, keep in mind that hot air can leave through the chimney. Also consider air gaps below doors, where cold air can leak through.

Conclusion

For most modern-day uses, 3 hours of heating are enough to warm your home. At the very least, your living room will be cozy and warm, while the rooms in the back (bedrooms, etc.) will be cooler.

If you want instant heat, I recommend looking into infrared space heaters. As soon as you turn on an infrared heater, it produces heat. It has next to no heat-up time. At maximum, it takes 1 minute.

You can check my favorite infrared heater here (click here to view it). Infrared heaters are perfect saviors if you are waiting for your primary heat source to heat up, but you are already shivering and need another source of warmth! Infrared heaters are absolutely worth it for people with cold hands and feet (such as myself)!

About the Author

Daniel Hirsch

Daniel is an electrical engineer, blogger, and author. He studied electrical engineering and information technology and decided to blog about heaters after working in the temperature sensing industry.