Low-Temperature Heating Systems
Low-temperature heating systems are where all domestic heating systems should be.
It's what's required if we are to install more heat pumps but also has huge benefits to gas boiler installations.
What is a low-temperature Heating System?
A heating system that is designed to meet desired temperatures by using a cooler system water to maintain higher efficencys and the other benefits that come with it.
So rather than having 70°c radiators, your radiators could be 25°c to 55°c yet still give comfort and even improve it.
Low-temperature heating systems typically don't exceed 35-55°c for space heating. This is absolutely achievable for most UK heating systems.
There are 3 ways of achieving a low-temperature heating system. Increased emitter (radiator) sizes, increased insulation, and low-temperature controls. These will all work individually but the best way to get your temperature as low as possible would be to do these altogether.
However, the most important and easy part is to set up and use modulating controls such as weather compensation or load compensation properly.
What this creates and the benefits are :
Comfort at Lower Room Temperatures
There is more radiant heat in each room creating a much warmer environment throughout, you also won't be using your own body heat to warm objects around you as hot goes to cold. this also creates cleaner safer air in the property as the hot air convects air though the property which could be carrying all sorts of allergens
A radiator with more convected heat will heat the air to above comfort temperature. As this cools the air will drop down the other side of the room, and objects like sofas and beds can disrupt this current.
The nature of high temperature, on/off heating is that the radiator also pulses. The room will overshoot the selected room temperature, then undershoot before the heating then kick back in.
A lower temperature system can minimise this 'over and undershooting' effect, and even simply match the heat input from the system, to the heat required to have a nice comfortable steady room.
All this means comfort can be found at lower temperatures and turning the stat down results directly in fuel bills saved.
Improved COP for Heat Pumps
There is more efficiency to be gained from running heat pumps at a lower temperature.
A heat pump running radiators at 55oc could use 40% more electricity than a system at 40°c. And we all know how much electricity costs.
This is to do with the temperature/pressure relationship heat pumps rely on. That is the higher the refrigerant gas pressure, the higher the temperature of that refrigerant gas.
Smaller radiators, or a call for a higher temperature for hot water demand, will mean the compressor has to drive harder to increase the fridge gas temperature. Even a small increase in pressure results in disproportionately higher use of power
