negawatt logo
... a unit of saved energy


Heating is one of the very important elements in our "healthy home, healthy living" standard. If you are experiencing a cold and hard to heat home or environment then you have probably insufficient or ineffective heating appliances. It is however typical to under heat our homes especially the older ones as the lack of insulation usually cost a lot of energy. Combining heating with insulation and ventilation can change your environment into an effective "healthy home".

Choosing the Right Heating

It might appear to be commonsense that if your home is cold you need to heat it, but that is not necessarily the case at all. Simply adding more heat may not be the best option - insulating and ventilating are often better, not only on the wallet, but for health reasons too. Try and achieve a level of heating that is throughout your home, not just the lounge while still having a cold bedroom, it's easier than you think. Traditionally heating just the lounge may seem financially practical but in fact by adding a little more heat to the colder part of the home can help in balancing the heat throughout the home. Perhaps central heating is what you want and we do strongly advise it but it will have a higher operating cost if you don't address insulation and heat loss fist.

Modern heating appliances although still electric and have the same level of efficiency as there bygone predecessors have become through technology considerably more effective which in term increases there efficiency. Wireless technology has even entered heating appliances which can customize a different heating regime for every room n the home.            

The extent to which you need to heat your home is directly related to two factors:

  • The thermal qualities of the building. The higher your heat losses through walls, ceilings, floors, windows, and doors, the more heat you need to add to maintain a comfortable living environment. High humidity accentuates the ambient temperature - making cold weather feel colder, and hot weather feel hotter. That's why the cold of a Central Otago winter (dry, low humidity) is not as chilling as a clammy Waikato winter's morning (humid). It's also why a sticky mid-summer night (say 24C) in Auckland may be very uncomfortable compared to a hot North Canterbury evening (28C).
  • Removing moisture from you home is often a lot cheaper and more beneficial from a health perspective than adding more heat. Signs that you need to look at a ventilation system are: condensation on windows, mould on ceilings and walls, mouldy/stuffy smells, asthma, general feeling of dampness in the home.

Which is better value: Insulation or Ventilation?

Moisture problems related to low surface temperatures may not be eliminated by increasing ventilation, and those related to high ventilation may not be eliminated by increasing surface temperatures. Understanding which factor dominates - low surface temperature or high moisture content will help in choosing the best strategy.

For example, consider an old, leaky,(draughty) poorly insulated home in winter time, which is suffering from condensation, mold and mildew. Since the house is leaky, it has a very high natural air change that dilutes interior airborne moisture levels and therefore maintains a low interior moisture level. Providing mechanical ventilation in this house by installing a fan with out heat will probably not control interior mold and mildew, since the interior moisture levels are already low. A better strategy would be to increase surface temperatures by insulating the house, thereby reducing relative humidity on surfaces.

House temperatures are dropped when occupants are sleeping and raised to normal levels when awake. However, when temperatures are reduced at night, humidity increases, which can cause mold and mildew to grow on cool surfaces.

Increasing interior temperatures can often control mold and mildew. Unfortunately, this means increasing energy consumption. An appropriate balance must be achieved between reducing energy consumption and avoiding surface moisture problems.

The best and most effective solution maybe the one you have not thought off.

Contact Negawatt for a home audit and advice


04 939 0313

Postal Address

PO Box 38-028
Wellington Mail Centre, NZ

© copyright negawatt ltd. all rights reserved. powered by behind the web