A 75,000 BTU heater can heat a room of between 1,900 and 3,700 square feet in a cold climate if there is little to no insulation. In more temperate climates the heater fares better, heating an uninsulated room of any size from 2,400 to 4,600 square feet.
Regardless of the logic you follow, the 30-year mark is at or close to the maximum lifespan you should expect from your furnace. Even though furnaces can last 30 years or beyond, most experts recommend that you start shopping for a new furnace when your existing unit is 15 years old.
between 15 and 20 years
On average, a residential furnace will last between 15 and 20 years. This time frame is dependent on installation quality, maintenance needs, proper repairs, and regular cleanings.
For example, a 300 square foot room typically requires 7,000 BTUs to maintain a comfortable temperature, while a 1,000 square foot room requires 18,000 BTUs.
To heat a 2,000 square foot home, you will need approximately 40,000 BTU’s of heating power.
Typically your furnace is centrally located in the home. It is usually located in an area such as a utility closet (by a cold air return), garage, attic, basement, or crawlspace; in the case of a heat-pump (a dual-system) it will be located outside of the home.
First and foremost, furnaces should be placed on rubber pads to minimize the noise they make. Then, if they happen to be located in the basement, they should be propped up on blocks or something else that keeps them at least four inches off the floor in case the basement floods.
While most HVAC companies will recommend a specific brand or type of AC unit, homeowners who source and install their own have the ultimate control over the process. If you find a brand that you like but your local HVAC place does not carry it, you can go DIY and still get the specific product that you want.
“Heat Pumps are not suitable for old buildings”
The heating control system can set to provide more gentle heat for longer periods than a gas boiler, which is typically set to give short bursts of high temperature for brief periods.
The World Health Organization (WHO) recommends indoor temperatures of at least 64°F (you can drop that down to 62°F at night if you’re really looking to save on your heating bill). But if you have infants, sick or elderly people in your household, then it’s recommended that you keep the thermostat set at 70°F.