In some ways, living in a Passivhaus makes you more in tune with the seasons – and with what what’s going on outside. As we enter into the spring the heat in the sun is increasing, as the angle of the sun is changing. We open the blinds of the sunspace all day and let the sun warm up the house. We haven’t had to put the heating on for weeks and the solar thermal panels are heating our hot water so the only gas we’re using is for cooking. Last night it was freezing again outside but it was 20 degrees in the bedroom – it’s comfortable. Even on a dull day, the house temperature is about 20 degrees/ possibly 19 degrees – but it will still retain the heat – the comfort is in the fabric.
Because the comfort is in the fabric of the house, the temperature will change very slowly. Opening windows in the house after (for example) cooking kippers give a through flow which changes the air but doesn’t affect the house temperature because the heat is in the fabric. For things like strong odours we could use the boost on the MVHR, but opening the windows is just that bit quicker.
Under the microscope
Leeds Met University are still doing ongoing readings and measurements of the house, including: temperatures in five rooms; humidity; meter readings; external temperatures; CO2 levels etc.
So far, they have found that the indoor temperature range is usually within 2 degrees – they were amazed with how stable it is. The Leeds Met team have been finding it useful to get information from occupants as to what’s going on in the house corresponding to fluctuations in their measurements and can ask us what happened on a certain day.
Kate’s birthday party even showed on the Leeds Met graph. We had a party with 11 extra people heating up the house – immediately you can see on the readings that the temperature stayed higher for longer on that day. The Leeds Met team can also see from their readings when we’re away because we’re not adding our body heat to the house, there is a slow decay of temperatures. When we return, the internal temperatures go up. Passive houses work best with people living in them, body heat, cooking, showering, electrical equipment etc, all contribute to the heating.
Geoff & Kate Tunstall, Denby Dale Passivhaus