Maximising Efficiency
The most important part of your new low carbon heating system is making sure you are comfortable and that your running costs are kept at a minimum. We will set up your system when we install or commission it and record the settings as part of your handover.
The main influencer of efficiency is how close your flow temperature is to the ground or air temperature (ground source vs air source heat pump). This can be referred to as the source to sink differential if you want to get technical.
It’s pretty straight forward and is the same in every other heat source; energy is required to raise water temperature so raising it faster OR raising it higher (and especially both) requires more input. In the case of a boiler this means burning more gas and with heat pumps it means using more electricity.
So at the most basic, lower temperature equals lower bills, easy right?
Control interface
The best way to achieve low temperature AND optimum comfort is by using a good controller and setting it up to run on weather compensation, in almost all properties weather compensation creates a more comfortable home with lowest running costs.
We will have done this for you during commissioning and recorded the settings, if for any reason the controller has changed from this setup, it could dramatically increase your running costs.
Room Controls
Many people, especially with underfloor heating like to have individual room controls. We suggest that these are still installed as they can protect against overheat but they A. should not be used to control the heat source (except in special circumstances) and B. should be set a little higher than the primary controller. For example we may set the weather compensation to achieve a room temperature of 21°c and the underfloor thermostat to 23°c so that it can help manage overheating from solar gains or secondary heat input. Similarly thermostatic radiator valves should be set to reduce potential overheating but as long as the system is balanced and adequately sized, they should rarely be activated to close.
To Zone or Not to Zone?
Zoning is common in larger buildings and historically was used in commercial properties to save money by only heating the spaces that were being used, the term means adding controls that shut off certain parts of the building while leaving others open. Most commonly this is with valves or pumps but also includes thermostatic radiator valves, improperly used these common valves can cause operational and efficiency problems which we’ll talk about later in this document.
Zoning is still a part of Part L Energy Efficiency requirements and in new build properties still implemented, despite usually making the heat pump (and boiler by the way) cycle more and reduce overall efficiency.
We almost always avoid doing this as the benefits are outweighed by the comfort gains, the intention in Part L (energy efficiency) is that turning off zones should reduce the amount of energy used to heat a building. In reality the “on” zones have to compensate for the “off” zones in most properties which increases the temperature requires to maintain the comfort level.
If the building has better insulation between the zoned spaces (an extension for example) then this may not be an issue and in very large or long houses zoning can still be well utilised to reduce waste.
In most normal 2-5 bed houses it is much cheaper to heat the whole space as one using weather compensation to maintain the lowest flow temperature possible while meeting the comfort levels outlined at design stage.
This simplistic approach means, fewer moving parts (no unnecessary pumps, valves, separation), less to go wrong, lower upfront materials cost and importantly a more open circuit which promotes a low and slow strategy which we have tested over many years to prove is the optimum solution.
For more information on Weather Compensation or Load Compensation - click here
