How to Calculate Heat Loss in a House

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How to Calculate Heat Loss in a House

Adding a radiant floor heating system to your home is a worthwhile investment. Not only will radiant flooring allow you to better utilize your space and feel more comfortable in the room, but it also will allow you enjoy significant, long-term cost savings. If you are interested in adding radiant floors to your home, then it is important to work closely with your contactor and decide on the right system for you at this time.

Your contractor may recommend having a home energy audit performed, in which a trained professional would conduct home heat loss calculations in order to determine how much heat is escaping from your room. Knowing the results of the heat loss equation will allow you and your contractor to choose a radiant flooring system that will effectively and efficiently heat the room of your choosing.

What is Heat Loss?

Heat loss is a calculation that measures the amount of heat energy that is transferred to the outside of a building through a surface or material. Most commonly, experts focus on calculating heat loss through a wall. A heat loss calculation will typically be measured in either BTUs or kW. Essentially, the heat loss through walls calculation identifies how much energy is required to keep a room or space at a desired temperature on the coldest possible day. It is important to know how to calculate heat loss through a wall, as this will tell you what type of heating system you need in order to efficiently heat your room to a comfortable temperature.

How to Calculate Heat Loss 

There are several steps that you, your contractor or your energy auditor need to take in order to calculate heat loss through wall. These steps include:

  • Identify the design temperature of your home. Keeping in mind that the heat loss equation is designed to help you understand how much energy it will take to heat your home on the coldest possible day, it’s important to know what the design temperature is inside your home. The design temperature is the difference between your preferred indoor temperature and the average coldest possible temperature in your local area. The design temperature, which is a very simply calculation to perform, is measured as Delta T. 
  • Determine the surface area of the room that you intend to heat. The actual size of the room that you are going to be working in plays a major role in determining its heat loss. When calculating heat loss through a wall, you will want to calculate the surface area by using the total length of an exterior wall and the height of that same wall. Eliminate the size of any windows or doors along that wall when calculating the surface area of the room. You will want to configure the surface area of doors and windows separately to complete the calculation.
  • Calculate both the R-value and U-value of your room. The R-value and U-value of the room help you to calculate heat loss through wall while keeping in mind the impact that insulation has on the room. A room with insulation in the wall will have a higher R-value than one without adequate insulation. You must first calculate your R-value, and then you can use that number to determine the U-value of the room.
  •  Determine the surface heat loss. The surface heat loss identifies how much heat is being lost through a wall as a result of doors and windows along the exterior wall. The surface heat loss can be calculated by determining the U-value of the doors and windows along that wall. Their U-values can be used as part of the heat loss equation in order to determine your total heat loss through a wall. 
  • Calculate the amount of air infiltration heat loss. Air infiltration heat loss is a separate figure that will identify the amount of heat that is being lost through small cracks, joints and caulk around the windows and doors on an exterior wall. Air infiltration heat loss may seem minor and insignificant, but it can actually have a major impact on the total heat loss in a given room. Air infiltration heat loss can be a fluid figure, however, as it is impacted by the wind speed and temperature changes in a room. There is a specific formula that can be used in order to determine air infiltration heat loss.
  • Use a heat loss formula to determine total heat loss. Once you have determined all of the various figures and calculations that are included as part of the heat loss equation, you can identify what the total heat loss is within your room. In order to begin calculating heat loss through a wall, you will need to add together the losses (in BTUs) from all walls, windows, doors and ceilings within the room. The final figure will tell you how much energy is required in order to consistently maintain your desired room temperature.

Using Home Heat Loss Calculations to Choose the Best Radiant Floors For Your Home

At Green Wave Distribution, we work closely with our clients to determine the best radiant floor solution for their homes. Not only do we consider the size of the space and the purpose for the room, but we also calculate heat loss through a wall in order to determine the best settings and configurations for the radiant flooring system. 

Our radiant flooring system stands apart from the competition, largely because of its innovative features, which include:

  • Self-regulating carbon polymer heating technology. This thin, flexible and durable technology prevents the system from overheating.
  • Low-voltage powered technology, which also improves the safety of the entire system.
  • Even heat distribution. Our flooring system will heat your room quickly and evenly, and prevent heat loss from occurring. 
  • Environmentally-friendly materials. All components of our system are designed with recycled material, and they are landfill biodegradable.

For more information about the importance of the BTU heat loss calculation and to learn more about the radiant flooring system that will be right for your home, contact us today.

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