Heating & Hot Water

Click on the question to display the answers.

Heating and Hot Water

  1. What temperature should I supply my heating and hot water at?

    • Heating Temperature: (30 - 55°C)

      According to the latest Part L1A and B (section 8 of Domestic Heating Compliance Guide 2006):

      • 45 - 55°C for radiators
      • 35 - 40°C for under floor
      • 30 - 35°C for fan convectors/fan coils

      Sanitary Hot Water Temperature: (45 - 50°C)

      WRAS (Water Regulation Advisory Scheme) (Schedule 2, Section 8 page 8.9)guidelines state that hot water needs to be stored above 60°C and distributed at no less than 55°C to prevent microbial growth (legionella). However, in recommendations it states that " hot water should be distributed less than 50°C " to avoid risk of scolding.

      Altherma controls has a built in weekly sanitation mode (legionella) it can not be overridden. You can select when it occurs (day of the week and time of the day) and temperature of sanitation (60 - 80°C).

      Daikin Altherma is unique as it allows you to set different water temperatures for heating and sanitary hot water, (e.g heating at 30 - 55°C and hot water at 50°C).

      Heating emitters:

      Fan coil / Convector
      Temperature 30-35°C

      Most efficient      		 Under Floor
      Temperature 35-40°C

      2nd Most efficient      		 Radiator
      Temperature 45-55°C

      3rd Most efficient

      Note: The lower the temperature:

      • The more efficient the boiler (any Gas, Oil, Heat Pump)
      • The more comfortable the heating temperature
      • The less danger from scolding (heating or hotwater)
      • The less losses from distribution pipes + sanitary hot water tank

      Sanitary Hot Water:

  2. Can the Daikin Altherma heat pump system provide heating and hot water at the same time?

    • Yes, Daikin Altherma comes complete with full controls, allowing you to have heating only, hot water only or heating and hot water.

  3. Can I get more than 55°C out of my refrigerant cycle (heat pump), as some claim?

    • Yes you can, but Space Air/DAIKIN would not recommend this as using the heat pump only (without additional auxiliary heating) to produce higher temperatures would result in higher pressures, causing a reduction of life expectancy and efficiency.

      Please Note:

      • Refer to Q1 (Heating & Hot Water section) and Q3 (Regulations)
      • The higher the water temperature set the less energy efficient any boiler would be (Gas, Oil or Heat Pump)

      Daikin Altherma works up to 55°C with a life expectancy of over 15 years with spare parts availability of more than 10 years.

  4. Is under floor heating more efficient in terms of energy consumption than a radiator system or fan convector?

    • No, as the efficiency of any boiler (Gas, Oil or HP) the heart of any heating system depends on the water temperature it supplies. The lower the temperature the more efficient it operates and less energy it consumes. Refer to Heating & Hot Water Q1.

      It recommends temperature for different heat emitters based on comfort + safety + efficiency temperatures relating to capital cost factors. Looking at these recommendations fan convectors / fan coils are the lowest hence the boiler system will be most efficient.

      Note: You can select radiators working at 40°C which would be as efficient as under floor, however, the dimensions might not be acceptable. However there are low compact temperature radiators that will be more practical.

      The factors that affect the heat emitter is the:

      • Amount of heat required
      • The water temperature
      • The flow

      The above will decide the surface area the emitter needs to be.