Maximizing Energy Savings: Will Precooling and Preheating Save Money for You?

Adelaide households can potentially save on energy costs by shifting heating and cooling times, if they have solar panels or are on a time-of-day tariff.
Precooling and preheating are frequently discussed online, but many articles lack the detailed information needed to determine if these methods are suitable for you. Continue reading to find out if they will work for your home.
For most Adelaide households, heating is the largest energy user with cooling often a close second. By shifting when you heat and cool, you may be able to have a significant impact on your energy costs, if you have solar panels or are on a time-of-day tariff. The idea is to start using your reverse cycle air conditioner when you are either generating electricity from your solar panels or are on a shoulder or off-peak tariff, rather than during peak tariff times.
One of the reasons this can work is that getting a home up to temperature, or cooling it down uses more energy than just keeping it at a constant temperature.
However, whether there is any benefit depends on several factors:

1. Size of Your Solar System relative to the Size of Your Air Conditioner(s):

The size of your solar system relative to your air conditioner's energy draw is crucial. If your solar panels generate enough electricity to cover the energy consumption of your air conditioner, you can save a lot on your energy bills. For example if you have a large ducted system (say 13kW or more) and average sized solar panels (say 6.5kW) you are less likely to save money, by trying to load shift your air conditioning. However, you may be able to cool the home down (or warm it up) so it is ready for you when you get home. (typically allow 20-30 minutes).

2. Daily Schedule:

Your daily routine plays a significant role. The times you get up in the morning and return home from work or school in the afternoon or evening will determine whether preheating or precooling your home will benefit you. (But remember if you are turning it on in the middle or late afternoon, your solar energy generated will already be dropping.)

3. Thermal Efficiency and Thermal Mass of Your Home:

1.  If your home is well-insulated and energy-efficient, you will retain the heat or cool air for longer periods, maximizing the benefits of precooling or preheating. On the other hand, if your home is like a leaky sieve, you will lose the energy quickly, and the benefits will be minimal, or potentially increase energy costs.
2. Thermal mass is the ability to store heat. If the home won’t store heat, then there is no point in trying to precool or preheat. Thermal mass generally means a concrete slab floor or cavity brick construction. 
3. Basically, if the house will remain cool or warm for the best part of a day, in spite of outside conditions then the thermal efficiency and thermal mass are adequate. Note that sometimes part of the house retains heat while another part doesn’t, in which case it may be worth precooling/preheating part of the house but not all of it.

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Rules of thumb:

Energy Auditing

By understanding these factors and making informed decisions, you can potentially save money on your energy bills while maintaining a comfortable home environment.

If you are considering precooling or preheating your home to save on energy costs, it may be worth getting a Low Energy Home energy audit which will specifically address whether this strategy will be beneficial for you. The advice given will increase the benefit of precooling or preheating. It will also help you save energy costs and increase comfort, so is cost justified anyway.

I guarantee I can identify cost effective savings, that pay for the assessment, or the assessment is free.

To find out more contact us.