Wellington and Manawatu Home Heating

There are many methods of heating homes and buildings. In Wellington and the lower half of the north island we have strong winds often and the wind chill factor means we need to keep our homes warm and insulate more than other parts of New Zealand.  Many of our older buildings are nothing more that a timber frame with weathboards.  This is a far from what is used overseas where buildings are 300mm thick stone and triple glazed windows with 200mm of wall insulation. Its no wonder we are cold and our power bills are high.

To Heat or Insulate

The cost of energy is increasing continually.  Is it cheaper to heat a building or insulate it well and have low heating costs?

This depends on whether it is cheap to insulate it and how long you can stay in the building to get a reasonable pay back period. If you will only be in a building a year or two it is not cheaper to insulate it unless that value can be got back when you leave.

These days insulation is required for new buildings. In the past buildings were not insulated. A typical pre 1980′s house has no insulation in the walls or ceiling. No double glazing or under floor insulation. This is astonishing to people from the Northern Hemisphere where in some countries windows are triple insulated. This is because historically energy was cheap.

Energy Increases

This all changed with the oil shocks of the 1970′s and the restrictions on building new power generating dams in New Zealand.  Energy costs have risen massively. In additon the gas utilities are now owned by the electric companies.

As energy rises dis-proportional to insulation costs it makes it cheaper to insulate.

Some buildings are hard to heat

For example 1900′s houses with no insulation, high stud, sash windows, no building paper, doors which are not close fitting, open fire places, louver type windows. These old homes can take massive amounts of energy and not have much impact impact on inside temperature. So how did they stay warm in the early years? Simple put on another layer of clothes. Stay in one room with the wood fire and then go to bed.  This is not acceptable today. Building owners want to be able to walk around with normal clothes and interact with others.

So what options do owners of old homes have. Well just three.

1. Do what they used to do above.

2. Insulate and achieve warm homes that are cheaper to heat.

or

3. Pay lots of money to  energy companies. The energy companies just love central heating in old homes particularly ones that are not insulated.

It is cheaper long term to retain the heat you have or redistribute it with ducting. For example taking heat from the kitchen or sunny lounge room or family room that contains the wood burner is cheaper than generating the heat in that room. How ever for spot heat in a bedroom a radiant electric heater will do.

Staying Long Term in  Building

Insulate all walls and ceilings. Double glaze the windows. PVC frames on doors and windows are even better. If using aluminium window frames powder coat them instead of anodizing. Powder coating has a greater effect of insulation than anodizing, but PVC is better.

General Tips

1. Only heat the rooms you are in and central heating is not good for that.
2. If you insist on central heating, install dampers to cut off parts of the house not being used.
3. Its a lot cheaper to insulate a centrally heated house. Ceilings and walls. Just do it. Double glaze all the large windows.
4. Use radiant heat.  You will feel it straight away.
5. Don’t use slow heaters such as oil heaters or wall convectors. By the time all the room is heated you have probably left the room or gone to work.  Keeping rooms warm for a long time allows huge heat loss. Spot heat is better.
6. Remove all louvered windows.
7. Ensure wooden windows are tight fitting or replace them.
8. Replace sash windows with PVC or new wooden versions.
9. Put thermostats on all heaters.
10. Turn heating off 30 minutes before going to bed.
11. Flame effect heaters are not for heating. They are decorative and expensive to run.
12. If using gas heating try getting heaters over 90% efficient.
13. If building a house put more windows on the sunny side and less on the south side. Always double glaze. Some new homes that are well insulated can get away with 2kw of heating in winter.
14. Windows that have lots of condensation have large heat loss. Double glaze and use a de-humidifier instead.

Heating Costs Verses Insulation

$500 per month heating x 6 months = $3000.00

3 years x annual heating costs $3000 = $9000.00 This is a lot of insulation and double glazing

You should easily pay for insulation in 5 or 6 years.

And the cost of energy just goes up much faster than inflation.

You get a better return on investment on insulating an un-insulated house than money in the bank.

 

Commercial Buildings – Large spaces

Radiant heat usually best particularly for open spaces where there are large openings such as roller doors  that are often open. Eg warehouses, restaurants, large retails stores.

Office spaces – heat pump often works as well as radiant and maybe cheaper.