Heat loss can occur through conduction, radiation, convection, or a combination of the three. Heat loss is the transfer of heat from the inside of a building to the outside through the fabric of a building. Heat loss figure is often expressed in terms of British Thermal Units (BTU) or kilowatts (kW). Determining the heat loss figure helps you determine the energy you need to keep a room at the desired temperature during cold days. It is important to understand what heat loss constitutes, how you can reduce it and how it will influence your choice of a floor heating system. Subtracting the heat loss figure from your heating system’s heat output will help you determine whether your underfloor heating system is adequate to heat up a room.
Heat loss affects underfloor heating installation. For instance, insulating your home can allow you to use the underfloor heating system as the primary source of heating. You may also choose to use the system alongside other heating systems. When buying an underfloor heating system, it’s important to understand its heat output. You should compare this output to the heat loss to ensure that your system will produce adequate heat. Determining the heat loss in advance will give you confidence in buying a heating system that you are sure will work efficiently after installation. A system’s heat output must be higher than the heat loss for it to provide ample heat to warm a home.
Heat loss is a function of heat transfer rates; it’s expressed in BTUs and kWs. On the other hand, the heat transfer rate is measured in U values. It’s important to determine the heat transfer rates in walls, roofs, and floors. The U value refers to the overall heat transfer coefficient. It portrays the heat transfer efficiency of different parts of a building. If a building is well insulated, it will have a lower U value. On the other hand, buildings with high U values have poor thermal performance, usually due to poor insulation.
The U value matters because it is the basis of energy and carbon reduction standards. The U value of a building determines whether the building falls within the required regulatory standards. When undertaking any building project, attaining regulatory approval is a must using SBEM for commercial and SAP for residential. You need to know the composition and thickness of any part of a building, including floor, wall, or roof, to determine its U value. Other important properties that you should consider are the heat transfer measurement and the conductivity of the building materials. The total heat loss flow rate is the sum of the U values of the individual elements of a building.
Why is Heat Loss Important?
There are several reasons why it is important to determine a building’s heat loss:
- Calculating the heat loss enables you to determine the necessary heating and power requirements to ensure that your building is adequately heated
- Determining the heat loss helps you to know whether your building meets the regulatory approvals
- You will be able to know if it’s possible to meet the comfort levels of a building’s occupants
- You can accurately determine the running costs and energy requirements of a heating system
It’s crucial to ensure that you understand the heat loss of a property or a room before you even install an underfloor heating system. This way, you will purchase a heating system that will meet the heating requirements of your property.
Reducing Heat Loss & Energy Consumption
There are several ways of reducing heat loss and energy consumption to make your home more energy-efficient:
- Reduction of the conduction losses by improving your property’s insulation
- Reduction of convective losses by minimizing air leakage
- Using efficient heating methods to reduce energy consumption
You can minimize heat loss and energy consumption by adding insulation. You should also ensure that there are no gaps in the insulation. Insulation boards come in handy for an underfloor heating system by enhancing a fast heat-up time and reducing heat loss to the subfloor. The good thing about the underfloor heating insulation boards is their ease of insulation. Insulation reduces the heat-up time, meaning that your home will warm up faster, and this saves significant energy and money. For instance, installing insulation on a concrete subfloor could reduce the heat up time from 2.5 hours to 20 minutes.
Choosing the Right Underfloor Heating System
With so many types of underfloor heating systems available in the market, how can you choose the right system for your property? You should always consider the heat loss of a room or a building while choosing an underfloor heating system. If you fail to consider the heat loss, you might end up buying an underfloor heating system that will not heat up a building or a room adequately to enhance the occupants’ comfort. It’s also advisable to consider a building’s insulation and consider whether you should increase the insulation. Underfloor heating systems require a certain level of insulation to minimize heat loss to the subfloor and enhance maximum heat output upwards.
The heat output of an underfloor heating system will vary depending on several factors:
The Size of the Heated Floor Area – the ratio of the heated floor area to the overall room size matters; it might be challenging to heat a room with the floor heating system only if the heated area is smaller than the overall floor area (less than 80 to 90%). However, the heating system might be adequate to heat the room if the room is well insulated. You could invest in an additional heat source in rooms like the bathroom, where the heated floor area is around 50% of the room size due to the fixtures. You can use supplemental heat sources like heated walls and towel rails to achieve the desired temperature.
The Flooring Type – You should consider your flooring type when choosing a heating system. Tile and stone flooring can be heated up to 29-30 degrees Celsius, but wooden flooring can’t be heated to more than 27 degrees Celsius.
The level of insulation – the insulation level will determine how much energy is lost to the subfloor
Your desired air temperature – You should choose a system that will adequately transfer heat into the air
The system’s maximum power – You will need between 65-85W/m² to insulate your home adequately
Some Important Aspects to Take Away:
Here are some important facts that you should understand about underfloor heating:
- If your property has a high heat loss, it will translate to higher energy consumption and costs
- The heat output of your heating system should always be higher than the heat loss of a building or room
- The energy requirements for any project you undertake should always fall within the regulatory requirements
- For an older building, you must be careful to assess the walls, windows, roof, and floors to get the correct U values. For newer buildings, most building materials come with U values and heat loss calculation. When assessing the U value of different elements, you should seek the assistance of a qualified energy assessment engineer.
- You should allow air movement between the inside and the outside of your property. You can achieve this through natural means or through an air handling system in airtight homes
- You should identify a building’s potential heat loss areas. You can use an infrared camera to identify potential areas of heat loss.
If you want to buy an indoor heating system but you aren’t sure whether it will be adequate to heat your home, you should contact Heavenly Heat. We will guide you and help you choose a heating system that will produce adequate heat for your home.