In winter, heating consumes the biggest chunk of household energy. Generating heat in an affordable, effective and sustainable way is not straight forward.
Some possible preferences in relation to your heating/cooling system could be:
- a building that is comfortable whilst ‘running free’ most of the time
- one or more spaces or whole of home can be made comfortable to suit usage
- easy to make comfortable after arriving home
- night-time comfort
- easy to use, economical and unobtrusive
- low capital cost
- deliver comfort for people with varying comfort requirements
- a warm focal point
- environmentally friendly
- low maintenance
- low peak demand
How much heating you require can depend on things such as climate, thermal performance, draughts and micro climate.
The better the thermal performance of a home, the less heating energy will be needed, along with potentially very different kinds of heating equipment. Insulated walls, ceilings, floors and advanced glazing are closer to room temperature than outside air, which means a small capacity heater can quickly provide excellent comfort. So thermally efficient homes typically need less intervention and management in winter.
Heat can be generated using gas, electricity, wood and solar energy
Reverse cycle heating/cooling
Resistive electric heating-fans and radiators
Wood and Pellet heating
Once we have produced the heat, it needs to be distributed to where it’s needed.
- locate a heater in each area that requires heating
- use heat-shifting ducts
- install ducted air or hydronic heating
- install in-floor heating
- use a combination of the above
- use local heating, blankets etc to ‘top up’ individual comfort
Single room heat delivery within efficient homes require smaller amounts of heat to warm up.
Ducted delivery of heat can have quite high distribution losses.
Hydronic heating can also lose large amounts of heat through its pipes.
Turning heat into comfort
This happens within the context of the building’s thermal performance.
The main options for providing heat to a space are:
- forced convection: a fan blowing warm air
- natural convection: a warm service heats air that rises naturally and warms the room
- radiant heating: a warm or hot surface radiates heat directly to objects and people exposed to it
- a combination of these: e.g. a hydronic panel will provide convected and radiant heat, as will a heated floor
- personal comfort provided by insulating clothes, blankets etc
- shifting of warm air to where it is more useful, e.g. with a heat shifting duct or ceiling fan
(originally published in ReNew Issue 127, written by Allan Pears)