The Best Thermostat Settings for Two Story Houses

Determining the best thermostat settings for a two story house is an interesting challenge with a number of factors to take into account. For example:

• do you have a thermostat on each level
• do you have individual thermostat controls at each ventilation/heating outlet throughout the house
• where do occupants spend their time at different points of the day

and probably most importantly

• what is your personal preference
• and, what compromises do you need to make to keep everyone in the building relatively happy!

In this post we lay out some of the points to think about, and provide some general rules to optimise your thermostat settings.

So why is finding the correct setting a challenge?

Well, essentially it comes down to three things

1. Physics

Hot air rises, cold air falls. In a two story house it’s difficult to avoid this effect (unless you have well insulated doors and ceilings between the different levels of your house). So however you setup your heating and ventilation system you will always be working with the fact that air is circulating around the house – depending on relative temperatures.

Also, there is an insulation effect. If your roof and walls are well insulated, then the summer heat and winter cold will have less effect on internal temperature – thus making the job of heating/cooling the space easier.

2. Objectives

• Do you want the space cooler than outside, warmer than outside, or neutral? Each scenario potentially requires a different approach.
• Is it enough to manage the temperature where the occupants are, or do you want the temperature managed throughout the house?

3. Zoning

For a two story house you’re going to get better results by splitting the two floors into different zones – each with their own thermostat. This gives you some ability to work with the natural air circulation in the house, rather than fighting it.

With one zone (and one thermostat) you have to accept more differentiation in temperature throughout the house – and you might end up carrying the thermostat around with you to optimise the temperature where you are!

And the solution?

In general, in the colder months, set the thermostat on the lower floor to be a degree or two higher than the setting on the upper floor (if you’ve got three floors, the same principle applies – so you will have three different settings, each one a degree or two lower as you go up through the house). In the warmer months you do the reverse – set the thermostat on the lower floor to be a degree or two lower than the setting on the upper floor.

The actual temperature you set is really a personal preference. Thermostat settings that people use might range from 65 degrees fahrenheit to 75F (18C to 24C) when warming the house in the colder months, and from 72 degrees fahrenheit to 77F (22C to 25C) when cooling the house in the hotter months

The reason for the difference across the seasons?

It’s just a question of managing you heating to optimise the cost of running the system as much as getting the right temperature – so you might accept a slightly warmer than comfortable house in the warmer months (though probably not a colder than comfortable house in the colder months!).

Conclusion

To summarise, there are three general rules for deciding the best thermostat settings for a two story house

Temperature cascades

Remember, hot air rises, cold air falls – so if you set the different levels of your house to slightly higher or lower temperatures (depending on the season) you will make cost effective use of this basic principle

The right temperature for you

Only you and the other people who occupy the space can determine the right temperature in the space. This can take some negotiation and compromise – the temperature guidelines given above are a good baseline to start from

Experiment and learn

As you try out different things and learn about the space you are in you will find the best thermostat settings for you – it really can’t be specified by someone else. Follow the guidelines above to get started, but remember, this is about achieving the right temperature in your house that works for you and your family. It’s not about proving or disproving the theory!