Boilers

How to get best value from your existing system – and lock in the savings when you upgrade. 

Top improvements to save costs and carbon

Technical Guide: Boiler tuning [pdf 407KB] [PDF, 407 KB]

  • Check and monitor the excess air.
  • Check for insulation damage and leaks.
  • In solid fuel combustion systems, check fuel is distributed evenly on the bed.
  • In liquid or gaseous fuel combustion systems, check the flame patterns are correct.
  • Make sure heat transfer surfaces are clean, or can be cleaned easily and often.
  • Review boiler set points to minimise short cycling.
  • Modify boiler sequencing to ensure the most appropriate boiler is matched to the demand.

New systems and upgrades – lock in the savings

Opportunities with fuel switching

High temperature electric heat pumps are the way to go if your temperatures needs are up to 100°C (or 120°C in some instances). They’re highly efficient, commercially available, and use New Zealand’s low carbon electricity.

For higher temperatures, the best option depends on your energy use profile.

  • Biomass is a viable alternative if your energy use is relatively stable. It can replace coal or be used as a co-firing option.
  • Electro-boilers may suit if you have peaking energy use. They’re convenient, low capital, low maintenance investments, with the downside of having a higher energy costs.
  • Mixed options can work for energy uses with a strong regular base (provided by a biomass boiler) and some peaking (provided by an electro-boiler). This helps you find the best economic balance between capital cost and energy cost.

Economiser options

If flue gases are above 120°C, investigate opportunities to fit an economiser.

Pre-heating combustion air

Combustion air is low temperature, so can be pre-heated by almost any waste heat stream. Pre-heating combustion air increases your boiler efficiency.