House Thermal Mass Works in Summer Too

House temperature ranges diagram

My house at Manilla, NSW, is in a climate with temperatures that are extreme, but comfortable on the average. To reduce extreme temperatures indoors, the house contains more than a hundred tonnes of thermal mass within a shell of insulation.
The “thermal mass” is the materials, such as bricks, stones, concrete, earth or water, that have high thermal capacity (See Notes below): they take in and give out a lot of heat.
Many people, who can see that having thermal mass inside a house will help to keep it warm in winter, think that the thermal mass will make it hard to keep the house cool in summer. They see many brick and brick-veneer houses in which thermal mass is exposed to the intense heat of the summer sun. In that case, thermal mass material does no good.

In this graph, I have used my last twelve months of temperature data to show the benefit of well-insulated thermal mass in summer as well as in winter.
Outdoor temperature in this year went as low as minus 4.0° Celsius and as high as plus 43.7°: a range of 47.7°. Continue reading

Cool, cloudy, wet October 2010

The daily weather logWeather log October 2010 Manilla

 

October days were very cool: no days went above 30°, when usually seven days do, and the 16th, at 14.2°, was 13° below normal. The following night (the only frost) was 10° below normal. A day earlier, overcast skies brought an extremely narrow daily temperature range (2.3°) on the 15th.
Rain fell on 8 days. The highest reading was 20.4 mm on the 4th.

Comparing October monthsClimate October 2010 Manilla

 

The mean daily maximum temperature (24.2°) was the lowest for October on this 12-year record. The mean daily mean temperature (17.7°) was low, but the mean daily minimum temperature (11.2°) was normal. The mean daily temperature range (13.1°) was a record low value.
Mean subsoil temperature was remarkably low: 17.4° against a 12-year October mean of 19.4°. The month ended with subsoil temperature (then 18.8°) trailing 22 days later than its usual date.
There were more cloudy mornings (58%) than in any October on this record. The mean early morning Dew Point (9.6°) was also high.
The rainfall of 85.4 mm is in the 80th percentile for October, far above the long-term average of 58 mm. Totals for groups of months up to six months are now all above the median, as is the thirty-year total.


Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Temperatures, including subsoil at 750 mm, and other data are from 3 Monash Street, Manilla.

Cool days in August 2010

The daily weather logWeather log August 2010 Manilla

August had no extremes. Only four days exceeded 20° (usually thirteen days), and only ten nights were frosty (usually fifteen). The subsoil temperature failed to rise during the month, ending at 13.5°, which is 1.0° cooler than normal.

Rain fell on 13 days, an August record for the decade, but the highest reading was only 10 mm.

Comparing August monthsClimate August 2010 Manilla

The mean daily maximum temperature (26.5°) was the lowest for November on this 12-year record. The mean daily temperature range (12.4°) was (with November 2008) a record low value.

Mean subsoil temperature (20.4°) was the lowest since November 1999. The month ended with subsoil temperature (then 22.2°) trailing only 10 days later than its usual date. It had begun the month 22 days late.
There were more cloudy mornings (53%) than in any November on this record.
The rainfall of 105.4 mm is in the 84th percentile for November, far above the long-term average of 67 mm. Totals for groups of months up to 15 months are now all above the median, as is the thirty-year total.


Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Temperatures, including subsoil at 750 mm, and other data are from 3 Monash Street, Manilla.

Autumn 2008 was dry and cool

Weather log autumn 2008

The daily weather log

Temperatures were about normal in mid-March and again during parts of May. Otherwise they were low. The daily temperature range was generally higher than usual, but was less on rainy days.
There were nine mild frosts, which is near the average.
Humidity was very low in early April and early May.
There were 13 rain days, which is normal. They were mainly in late April and mid-May, for a very low total of 37 mm. April the 24th was the wettest day, with 12.8 mm.
Cloud varied a lot from day to day. Clear skies were common in March.

Comparing autumn seasons

This autumn was very cool: mean daily mean temperature and minimum temperature are the lowest in the ten year record. Mean daily maximum temperature was lower in 2003, which is one of three autumns sharing the next coolest mean temperature.
This autumn’s very cool nights (8.2°) caused the largest daily temperature range on the graph (16.9°), similar to the 16.8° of 2005. Both came with very low rainfall,
Autumn humidity seems to have decreased through the decade, with this autumn’s Dew Point of 6.4° the lowest.
This graph includes some very dry autumns. Autumn 2005 was the 7th driest on record, in the 6th percentile for autumn rainfall. This autumn was similar, in the 7th percentile. Autumn 2002 was in the 18th percentile, as that year’s drought had not fully developed. By contrast, autumn 2003 and 2007 were wet, in the 72nd and 75th percentiles.
(Contrary to the forecast, this autumn was dry. It was one of twelve autumns on record that had less than one fifth of the preceding summer’s rainfall. Three of the twelve were 2005, 2006, and 2008. This is amazing: something that usually happens one year in ten happened three years in four! Another three of the twelve were 1971, 1973, and 1976. At that time it was three years in six.)
At 26% cloudy mornings, this autumn was normal.

Climate autumn 2008

Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Dew Point values before August 2005 are from Tamworth Airport 6 am data supplied by the Bureau of Meteorology. Temperatures, including subsoil at 750 mm, and other data are from 3 Monash Street, Manilla.