# Encyclopedia

.Thermal mass (Cth, also called thermal capacitance or heat capacity) is the capacity of a body to store heat.^ THERMAL MASS The thermal mass of the house is a measure of its capacity to store and regulate internal heat.

^ The thermal mass > stores > the heat to be radiated later.
• [BLDG-SIM] Thermal mass walls 25 September 2009 9:53 UTC www.gard.com [Source type: FILTERED WITH BAYES]
• [BLDG-SIM] Thermal mass walls 25 September 2009 9:53 UTC www.gard.com [Source type: FILTERED WITH BAYES]

^ GBlist: thermal mass / time constants / "diurnal heat capacity" .
• GBlist: thermal mass / time constants / "diurnal heat capacity" 25 September 2009 9:53 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

It is typically measured in units of J/°C or J/K (which are equivalent). .If the body consists of a homogeneous material with sufficiently known physical properties, the thermal mass is simply the mass of material present times the specific heat capacity of that material.^ "Thermal Mass" refers to the ability of a material to retain heat.
• Thermal Mass - Radiant Floor Heating - The Concrete Network 25 September 2009 9:53 UTC www.concretenetwork.com [Source type: General]

^ The time delay due to the thermal mass is known as a time lag.
• | Thermal Mass | Ecotect 25 September 2009 9:53 UTC ecotect.com [Source type: FILTERED WITH BAYES]

^ Both heat capacity and conductivity give rise to what is known as the thermal mass effect.
• | Thermal Mass | Ecotect 25 September 2009 9:53 UTC ecotect.com [Source type: FILTERED WITH BAYES]

.For bodies made of many materials, the sum of heat capacities for their pure components may be used in the calculation, or in some cases (as for a whole animal, for example) the number may simply be measured for the entire body in question, directly.^ To do that we need to calculate component and > total mass, then the heat storage capacity by using the specific heat for > each.
• GBlist: thermal mass / time constants / "diurnal heat capacity" 25 September 2009 9:53 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ I use a 50lt converted s/s keg for my mashing,the heated water is added to the cold keg and I calculate the mash in temp using promash.The thermal mass is set at 0.
• HOMEBREW Digest #3746 Thu 27 September 2001 25 September 2009 9:53 UTC hbd.org [Source type: FILTERED WITH BAYES]

^ Typical thermal mass materials include concrete, brick, masonry, tile and mortar, water, and rock or other materials with high heat capacity.
• Energy Glossary - Letter T 25 September 2009 9:53 UTC www.energy.ca.gov [Source type: Reference]

.As an extensive property, heat capacity is characteristic of an object; its corresponding bulk property is specific heat capacity, expressed in terms of a mass or number of moles or some other measure of the amount of material, which must be multiplied by similar units to give the heat capacity of the entire body of material.^ It does not give a measurement of storing thermal heat in mass.

^ Specific heat Specific heat of the material.
• Simulate mass in thermal systems - Simulink 25 September 2009 9:53 UTC www.mathworks.com [Source type: Academic]

^ Specific heat is the amount of heat a material can hold per unit of mass.
• | Thermal Mass | Ecotect 25 September 2009 9:53 UTC ecotect.com [Source type: FILTERED WITH BAYES]

.Thus the heat capacity can be equivalently calculated as the product of the mass m of the body and the specific heat capacity c for the material, or the product of the number of moles of molecules present n and the molar specific heat capacity $\bar c$.^ Specific heat Specific heat of the material.
• Simulate mass in thermal systems - Simulink 25 September 2009 9:53 UTC www.mathworks.com [Source type: Academic]

^ Specific heat is the amount of heat a material can hold per unit of mass.
• | Thermal Mass | Ecotect WIKI 25 September 2009 9:53 UTC squ1.org [Source type: FILTERED WITH BAYES]
• | Thermal Mass | Ecotect 25 September 2009 9:53 UTC ecotect.com [Source type: FILTERED WITH BAYES]

^ The property is characterized by mass of the material and its specific heat.
• Simulate mass in thermal systems - Simulink 25 September 2009 9:53 UTC www.mathworks.com [Source type: Academic]

.For discussion of why the heat storage abilities of pure substances vary, see factors that affect specific heat capacity.^ This creates a large storage capacity for heat.
• Trombe Wall 25 September 2009 9:53 UTC www.eebt.org [Source type: FILTERED WITH BAYES]

^ The ASHRAE "Red Book" for design and analysis of passive solar buildings has a companion update volume (supplement) that contains discussion of diurnal heat capacity and why it is important for good performance in passive solar buildings.
• GBlist: thermal mass / time constants / "diurnal heat capacity" 25 September 2009 9:53 UTC www.ibiblio.org [Source type: FILTERED WITH BAYES]

^ Water has one of the highest heat capacities at around 4.2 kJ/kg°K, while most building materials vary from around 0.8 to 1.3 kJ/kg°K. Another property of a material, as discussed in the thermal resistance topic, is its conductivity or the ease with which heat can travel through it.
• | Thermal Mass | Ecotect WIKI 25 September 2009 9:53 UTC squ1.org [Source type: FILTERED WITH BAYES]
• | Thermal Mass | Ecotect 25 September 2009 9:53 UTC ecotect.com [Source type: FILTERED WITH BAYES]

.Thermal mass as a concept is most frequently applied in the field of building design.^ Green Building magazine : THERMAL MASS .

^ Making the most of thermal mass.
• Abstracts: A limited vision of our future. Making the most of thermal mass. Dazed young, professionals stumble blindly, trying to work out what Part 3 is 25 September 2009 9:53 UTC www.faqs.org [Source type: Academic]

^ The use of thermal mass can do much to simplify the design of buildings and their services.
• A changing climate for thermal mass - Modern Building Services 25 September 2009 9:53 UTC www.modbs.co.uk [Source type: FILTERED WITH BAYES]

.In this context, thermal mass provides "inertia" against temperature fluctuations, sometimes known as the thermal flywheel effect.^ This is sometimes called the thermal flywheel effect because, like a flywheel, the thermal mass can store and even out fluctuations in temperature.

^ This is also an important aspect of the thermal mass effect.
• | Thermal Mass | Ecotect WIKI 25 September 2009 9:53 UTC squ1.org [Source type: FILTERED WITH BAYES]
• | Thermal Mass | Ecotect 25 September 2009 9:53 UTC ecotect.com [Source type: FILTERED WITH BAYES]

^ M. Blanks on October 30, 1999 at 01:10:40: The use of masonry in hot climates provides the benefit of thermal mass.
• Re: Efficiency, Thermal Mass, & Insulation... 25 September 2009 9:53 UTC www.cmpconline.org [Source type: Reference]

[1] .For example, when outside temperatures are fluctuating throughout the day, a large thermal mass within the insulated portion of a house can serve to "flatten out" the daily temperature fluctuations, since the thermal mass will absorb heat when the surroundings are hotter than the mass, and give heat back when the surroundings are cooler.^ If the thermal mass is large, the thermal response will be slow.
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

^ It does not give a measurement of storing thermal heat in mass.

^ Water's thermal mass gives off its heat to the air as it's cooling.
• How to Save Home Energy Using Thermal Mass | eHow.com 25 September 2009 9:53 UTC www.ehow.com [Source type: General]

.This is distinct from a material's insulative value, which reduces a building's thermal conductivity, allowing it to be heated or cooled relatively separate from the outside, or even just retain the occupants' body heat longer.^ This dramatically reduces heating and cooling costs.

^ "Thermal Mass" refers to the ability of a material to retain heat.
• Thermal Mass - Radiant Floor Heating - The Concrete Network 25 September 2009 9:53 UTC www.concretenetwork.com [Source type: General]

^ The heating or cooling requirements can be reduced when a building is unoccupied or when occupants are asleep.
• Energy Glossary - Letter T 25 September 2009 9:53 UTC www.energy.ca.gov [Source type: Reference]

.Thermal mass may also be used for bodies of water, machines or machine parts, living things, or any other structure or body in engineering or biology.^ Many things can act as thermal mass in the greenhouse, including wood, soil in raised beds, concrete, block, or brick foundations, or even the floor of the greenhouse.
• What is thermal mass? - 25 September 2009 9:53 UTC faq.gardenweb.com [Source type: General]

^ Thermal mass materials have the ability to conduct and store energy, both heat and cold, and to release that energy back into the living space when it's needed.
• Solar Thermal Mass 25 September 2009 9:53 UTC www.epsea.org [Source type: FILTERED WITH BAYES]

^ Common materials used as a thermal mass include adobe, mud, stones, or even tanks of water.

.The term "heat capacity" is more commonly used.^ Water can store far more heat for a given mass than any other commonly available material.
• What is thermal mass? - 25 September 2009 9:53 UTC faq.gardenweb.com [Source type: General]

^ THERMAL POWER PLANT -- any stationary or floating electrical generating facility using any source of thermal energy, with a generating capacity of 50 megawatts or more, and any facilities appurtenant thereto.
• Energy Glossary - Letter T 25 September 2009 9:53 UTC www.energy.ca.gov [Source type: Reference]

^ (Heat capacity Is the technical term for thermal mass.
• Welcome to DesertBlock.com 25 September 2009 9:53 UTC www.desertblock.com [Source type: FILTERED WITH BAYES]

## Basic equation

The equation relating heat energy to thermal mass is:
$Q = C_\mathrm{th} \Delta T\,$
where .Q is the heat energy transferred, Cth is the thermal mass of the body, and ΔT is the change in temperature.^ An object with higher thermal mass can hold more heat energy.
• Smart Homes: Materials with a high thermal mass can help your house stay warmer 25 September 2009 9:53 UTC www.seattlepi.com [Source type: General]

^ Sunlight is absorbed by the collector and the heat transferred to the thermal mass.

^ Thermal mass is an energy store.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

For example, if 250 J of heat energy is added to a copper gear with a thermal mass of 38.46 J/°C, its temperature will rise by 6.50 °C.

## Thermal mass in buildings

.Thermal mass is effective in improving building comfort in any place that experiences these types of daily temperature fluctuations—both in winter as well as in summer.^ A high thermal mass will reduce fluctuations in internal temperature during the summer.

^ Green Building magazine : THERMAL MASS .

^ Thermal Mass Controversy in the building world.
• Thermal Mass - Associated Content - Topic - associatedcontent.com 25 September 2009 9:53 UTC www.associatedcontent.com [Source type: General]

.When used well and combined with passive solar design, thermal mass can play an important role in major reductions to energy use in active heating and cooling systems.^ Water's thermal mass gives off its heat to the air as it's cooling.
• How to Save Home Energy Using Thermal Mass | eHow.com 25 September 2009 9:53 UTC www.ehow.com [Source type: General]

^ Passive solar heating systems rely on interior thermal mass.
• Welcome to DesertBlock.com 25 September 2009 9:53 UTC www.desertblock.com [Source type: FILTERED WITH BAYES]

^ Designs lacking thermal mass are simply not able to store passive solar energy properly.
• Sustainable design, passive solar house HTM holistic housing consultation packages for the earthhome do-it-yourselfer. 25 September 2009 9:53 UTC www.thenaturalhome.com [Source type: General]

### Properties required for good thermal mass

Ideal materials for thermal mass are those materials that have:
.Any solid, liquid, or gas that has mass will have some thermal mass.^ Thermal mass is simply a solid or liquid material that will absorb and store warmth and coolness until it is needed.

^ However, trying to compare insulation R-factors to thermal mass retention is somewhat like trying to compare the efficiency of electric cars to gas powered autos.
• Hurricane proof, disaster proof, Earth sheltered homes that are environmentallyfriendly. 25 September 2009 9:53 UTC www.formworksbuilding.com [Source type: FILTERED WITH BAYES]

^ Thermal mass is shown as solid black and speckled areas.
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

.A common misconception is that only concrete or earth soil has thermal mass; even air has thermal mass (although very little.^ They have very low thermal masses.
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

^ Very low thermal mass .
• Imerys Kiln Furniture - Bone China 25 September 2009 9:53 UTC www.ikf-solutions.com [Source type: General]

^ Too much thermal mass is very bad.

)
.A table of volumetric heat capacity for building materials is available here, but note that their definition of thermal mass is slightly different.^ Table 6 : Volumetric heat capacity of different materials .
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

^ The volumetric heat capacity referring to 1 m 3 volume describes the materials well.
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

^ Definition of thermal mass .
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

[2]

### Use of thermal mass in different climates

.The correct use and application of thermal mass is dependent on the prevailing climate in a district.^ Thermal mass is only beneficial to the internal climate under varying internal and external conditions due to the storage capacity (time lag) of the building fabric.
• [BLDG-SIM] Thermal mass walls 25 September 2009 9:53 UTC www.gard.com [Source type: FILTERED WITH BAYES]

^ There are a number of situations where thermal mass could either not be useful at all or even increase energy use.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

^ Back Issues » 2007 » October A changing climate for thermal mass Published: October 2007 .
• A changing climate for thermal mass - Modern Building Services 25 September 2009 9:53 UTC www.modbs.co.uk [Source type: FILTERED WITH BAYES]

#### Temperate and cold temperate climates

.Thermal mass is ideally placed within the building and situated where it still can be exposed to winter sunlight (via windows) but insulated from heat loss.^ I have not adjusted insulation or thermal mass.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

^ Green Building magazine : THERMAL MASS .

^ Thermal Mass Controversy in the building world.
• Thermal Mass - Associated Content - Topic - associatedcontent.com 25 September 2009 9:53 UTC www.associatedcontent.com [Source type: General]

.The thermal mass is warmed passively by the sun or additionally by internal heating systems during the day.^ Passive solar heating systems rely on interior thermal mass.
• Welcome to DesertBlock.com 25 September 2009 9:53 UTC www.desertblock.com [Source type: FILTERED WITH BAYES]

^ Most passive solar homes have large areas of south facing glazing that allows the suns energy to enter the space and then typically store this within some kind of thermal mass.
• Trombe Wall 25 September 2009 9:53 UTC www.eebt.org [Source type: FILTERED WITH BAYES]

^ Thermal mass materials have the ability to conduct and store energy, both heat and cold, and to release that energy back into the living space when it's needed.
• Solar Thermal Mass 25 September 2009 9:53 UTC www.epsea.org [Source type: FILTERED WITH BAYES]

.Heat stored in the mass is then released back into the interior during the night.^ Then during the night this heat is slowly released into the rooms.

^ At night the heat is released.
• Welcome to DesertBlock.com 25 September 2009 9:53 UTC www.desertblock.com [Source type: FILTERED WITH BAYES]

^ "As well as cooler internal temperatures, these benefits also include reduced heating bills in the winter as instead of purging the day-time heat gains with night-time air, the stored heat is allowed to radiate back into the building".
• The Concrete Centre explain thermal mass: News from The Concrete Centre 25 September 2009 9:53 UTC www.buildingtalk.com [Source type: FILTERED WITH BAYES]

.It is essential that it be used in conjunction with the standard principles of passive solar design.^ You may remember that it was explained in the previous article in April that passive solar heating is defined as using the house itself as a solar collector.

^ We are stuck with the houses weve already got, which meet solar principles by accident rather than design.

^ What is the most cost effective, ecologically sound, completely sustainable, easy to convert, non-electric, zero-energy, radiant passive solar design concept?
• Sustainable design, passive solar house HTM holistic housing consultation packages for the earthhome do-it-yourselfer. 25 September 2009 9:53 UTC www.thenaturalhome.com [Source type: General]

.Any form of thermal mass can be used.^ We modeled the Siegel house with and without the thermal mass of the rock wall in order to compare the differences in energy use between the two cases.
• The Siegel House - Rock Wall Thermal Mass 25 September 2009 9:53 UTC www.arch.ced.berkeley.edu [Source type: FILTERED WITH BAYES]

^ In very cold and sub-polar regions, buildings are usually highly insulated with very little exposed thermal mass, even if it is used for structural reasons.
• | Thermal Mass | Ecotect WIKI 25 September 2009 9:53 UTC squ1.org [Source type: FILTERED WITH BAYES]
• | Thermal Mass | Ecotect 25 September 2009 9:53 UTC ecotect.com [Source type: FILTERED WITH BAYES]

^ The thermal mass would actually be sand used in conjunction with a solar pool heater along the north wall.
• thermal mass - Greenhouses & Garden Structures Forum - GardenWeb 25 September 2009 9:53 UTC forums2.gardenweb.com [Source type: General]

.A concrete slab foundation either left exposed or covered with conductive materials e.g.^ The Termodeck approach to exploiting thermal mass is pass air through the cores of exposed, hollowcore concrete slabs before it enters the space.
• A changing climate for thermal mass - Modern Building Services 25 September 2009 9:53 UTC www.modbs.co.uk [Source type: FILTERED WITH BAYES]

^ Materials such as ceramic floor tiles or brick make better choices for covering a direct gain slab.
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

tiles; is one easy solution. .Another novel method is to place the masonry facade of a timber-framed house on the inside ('reverse-brick veneer').^ I plan to document the construction of both the bread oven and rumford fireplace on my timber frame house blog.
• Massie Oven 25 September 2009 9:53 UTC www.rumford.com [Source type: General]

.Thermal mass in this situation is best applied over a large area rather than in large volumes or thicknesses.^ If the thermal mass is large, the thermal response will be slow.
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

^ Volume of the thermal mass in [m3].

^ Most passive solar homes have large areas of south facing glazing that allows the suns energy to enter the space and then typically store this within some kind of thermal mass.
• Trombe Wall 25 September 2009 9:53 UTC www.eebt.org [Source type: FILTERED WITH BAYES]

7.5–10 cm (3-4") is often adequate.
.Since the most important source of heat is from the sun, the ratio of glazing to thermal mass is an important factor to consider.^ This is also an important aspect of the thermal mass effect.
• | Thermal Mass | Ecotect 25 September 2009 9:53 UTC ecotect.com [Source type: FILTERED WITH BAYES]

^ Thermal mass materials have the ability to conduct and store energy, both heat and cold, and to release that energy back into the living space when it's needed.
• Solar Thermal Mass 25 September 2009 9:53 UTC www.epsea.org [Source type: FILTERED WITH BAYES]

^ Adequate thermal mass will store enough heat indoors during the day to prevent the backup resistance heat from running when outside temperatures drop at night.
• How to Save Home Energy Using Thermal Mass | eHow.com 25 September 2009 9:53 UTC www.ehow.com [Source type: General]

Various formulas have been devised to determine this.[3] .As a general rule, additional solar-exposed thermal mass needs to applied in a ratio from 6-8:1 for any area of north facing (Southern Hemisphere)(south facing, Northern Hemisphere) glazing above 7% of the total floor area.^ How much thermal mass do i need!?
• How much thermal mass do i need!? - Greenhouses & Garden Structures Forum - GardenWeb 25 September 2009 9:53 UTC forums2.gardenweb.com [Source type: General]

^ General principles about thermal mass .
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

^ In the northern hemisphere most of its windows are facing the south (in the southern hemisphere its windows face north).
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

e.g. a .200 m2 house with 20 m2 of north facing glazing has 10% of glazing by total floor area; 6 m2 of that glazing will require additional thermal mass.^ Tile flooring adds additional thermal mass to the room.
• Smart Homes: Materials with a high thermal mass can help your house stay warmer 25 September 2009 9:53 UTC www.seattlepi.com [Source type: General]

^ Be careful to avoid South facing houses with large areas of glazing on the North side.

^ We were unable to confirm our hypothesis that the rock wall is functioning as an effective thermal mass in the Siegel house.
• The Siegel House - Rock Wall Thermal Mass 25 September 2009 9:53 UTC www.arch.ced.berkeley.edu [Source type: FILTERED WITH BAYES]

.Therefore, 36-48 m2 of solar-exposed thermal mass is required.^ In conventional high-R construction, AAC blocks have a place, but if you want a truly sustainable design passive solar home, choose high thermal mass.
• Sustainable design, passive solar house HTM holistic housing consultation packages for the earthhome do-it-yourselfer. 25 September 2009 9:53 UTC www.thenaturalhome.com [Source type: General]

^ The thermal mass would actually be sand used in conjunction with a solar pool heater along the north wall.
• thermal mass - Greenhouses & Garden Structures Forum - GardenWeb 25 September 2009 9:53 UTC forums2.gardenweb.com [Source type: General]

^ In other words it is necessary to understand the effects of insulation and thermal mass and the addition of energy into the housing envelop, either from solar or other sources.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

The exact requirements vary from climate to climate.

#### Hot, arid climates (e.g. desert)

.This is a classical use of thermal mass.^ I use a 50lt converted s/s keg for my mashing,the heated water is added to the cold keg and I calculate the mash in temp using promash.The thermal mass is set at 0.
• HOMEBREW Digest #3746 Thu 27 September 2001 25 September 2009 9:53 UTC hbd.org [Source type: FILTERED WITH BAYES]

^ There are a number of situations where thermal mass could either not be useful at all or even increase energy use.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

^ In very cold and sub-polar regions, buildings are usually highly insulated with very little exposed thermal mass, even if it is used for structural reasons.
• | Thermal Mass | Ecotect 25 September 2009 9:53 UTC ecotect.com [Source type: FILTERED WITH BAYES]

.Examples include adobe or rammed earth houses.^ Then I decided to > read about other types of natural construction and have since read 20 plus, > (every) book on the subject, including stone houses, adobe, rammed > earth,cob, earthship, etc.etc.
• GSBN: Digest for 6/25/03 25 September 2009 9:53 UTC greenbuilder.com [Source type: General]

^ Then > I decided to read about other types of natural construction and have > since read 20 plus, (every) book on the subject, including stone > houses, adobe, rammed earth,cob, earthship, etc.etc.
• GSBN: Digest for 6/25/03 25 September 2009 9:53 UTC greenbuilder.com [Source type: General]

^ Then I decided to read about other types of natural construction and have since read 20 plus, (every) book on the subject, including stone houses, adobe, rammed earth,cob, earthship, etc.etc.
• Re: GSBN:Ask the Experts 25 September 2009 9:53 UTC greenbuilder.com [Source type: General]
• GSBN: Digest for 6/25/03 25 September 2009 9:53 UTC greenbuilder.com [Source type: General]

Its function is highly dependent on marked diurnal temperature variations. .The wall predominantly acts to retard heat flow from the exterior to the interior during the day.^ In the summer months, interior masonry can be "precooled" by nighttime ventilation of the building to better absorb heat and cool the building during the day For non-architectural inquiries, click here .
• Welcome to DesertBlock.com 25 September 2009 9:53 UTC www.desertblock.com [Source type: FILTERED WITH BAYES]

^ The wall is left uninsulated so that the heat from the sunspace can be conducted through to the interior of the house.
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

^ Figure 2 - A comparison of hourly heat flow in a small space with increasing thickness of masonry wall (from 10mm to 200mm).
• | Thermal Mass | Ecotect WIKI 25 September 2009 9:53 UTC squ1.org [Source type: FILTERED WITH BAYES]

.The high volumetric heat capacity and thickness prevents heat from reaching the inner surface.^ If the sunlight from the clerestory first strikes high in the space, then the wall surface should be light in color to diffuse the light and heat downwards into the space.
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

^ The volumetric heat capacity referring to 1 m 3 volume describes the materials well.
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

^ The heat capacity of a room or a building is then calculated by multiplying the heat capacity of each element by its total surface area in contact with the internal air.
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

.When temperatures fall at night, the walls re-radiate the heat back into the night sky.^ If the sunlight from the clerestory first strikes high in the space, then the wall surface should be light in color to diffuse the light and heat downwards into the space.
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

^ H ot zone The ideal place for hot rooms is in the very centre of the house, with no external walls so that the heat can radiate out into the rest of the house.

^ The ancients also gained great insights into the potential of architecture to modify the sun's shadow and radiant heat.
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

.In this application it is important for such walls to be massive to prevent the ingress of heat into the interior.^ THERMAL BREAK (thermal barrier) -- An element of low heat conductivity placed in such a way as to reduce or prevent the flow of heat.
• Energy Glossary - Letter T 25 September 2009 9:53 UTC www.energy.ca.gov [Source type: Reference]

^ If the sunlight from the clerestory first strikes high in the space, then the wall surface should be light in color to diffuse the light and heat downwards into the space.
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

^ H ot zone The ideal place for hot rooms is in the very centre of the house, with no external walls so that the heat can radiate out into the rest of the house.

#### .Hot humid climates (e.g.^ The "best" approach depends on many factors: Climate: temperature, relative humidity and wind (since I know this is a hot-dry climate, I won't even get into the discussion of relative humidity... Re: GSBN:Ask the Experts 25 September 2009 9:53 UTC greenbuilder.com [Source type: General] GSBN: Digest for 6/25/03 25 September 2009 9:53 UTC greenbuilder.com [Source type: General] sub-tropical and tropical)

.The use of thermal mass is the most challenging in this environment where night temperatures remain elevated.^ In a structure, building materials with high thermal mass, such as concrete, brick, or tile, can absorb heat during the day and release it slowly back into the building at night, helping to keep interior temperatures constant.
• Definition of Thermal mass - Blue Egg Glossary 25 September 2009 9:53 UTC www.blueegg.com [Source type: General]

^ I use a 50lt converted s/s keg for my mashing,the heated water is added to the cold keg and I calculate the mash in temp using promash.The thermal mass is set at 0.
• HOMEBREW Digest #3746 Thu 27 September 2001 25 September 2009 9:53 UTC hbd.org [Source type: FILTERED WITH BAYES]

^ There are a number of situations where thermal mass could either not be useful at all or even increase energy use.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

Its use is primarily as a temporary heat sink. However, it needs to be strategically located to prevent overheating. .It should be placed in an area that is not directly exposed to solar gain and also allow adequate ventilation at night to carry away stored energy without increasing internal temperatures any further.^ Night ventilation is then used to purge heat stored in the slabs, and is relatively effective as the diurnal temperature swing in the UK is rarely less than 5 K — the minimum temperature difference needed to get a worthwhile level of heat flow in and out of the concrete.
• A changing climate for thermal mass - Modern Building Services 25 September 2009 9:53 UTC www.modbs.co.uk [Source type: FILTERED WITH BAYES]

^ This is because energy heat from the thermal mass can flow directly to the outside of the house instead of having to heat the internal air first.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

^ WORKING WITH THE SUN The contribution of the sun to a houses internal heat is called the solar gain.

.If to be used at all it should be used in judicious amounts and again not in large thicknesses.^ This can be used as a rule of thumb in common structures with the caveat that if there is an insulation layer in the first 10 cm, only the thickness up to the insulation layer should be considered.
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

### Materials commonly used for thermal mass

• Water. .Water has the highest volumetric heat capacity of all commonly used material.^ Table 6 : Volumetric heat capacity of different materials .
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

^ The volumetric heat capacity referring to 1 m 3 volume describes the materials well.
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

^ Water has one of the highest heat capacities at around 4.2 kJ/kg°K, while most building materials vary from around 0.8 to 1.3 kJ/kg°K. Another property of a material, as discussed in the thermal resistance topic, is its conductivity or the ease with which heat can travel through it.
• | Thermal Mass | Ecotect WIKI 25 September 2009 9:53 UTC squ1.org [Source type: FILTERED WITH BAYES]
• | Thermal Mass | Ecotect 25 September 2009 9:53 UTC ecotect.com [Source type: FILTERED WITH BAYES]

.Typically, it is placed in large container(s), acrylic tubes for example, in an area with direct sunlight.^ Being in direct sunlight is always best, but solar storage tubes perform a subtle sunroom cooling in the shade, too.
• Sustainable design, passive solar house HTM holistic housing consultation packages for the earthhome do-it-yourselfer. 25 September 2009 9:53 UTC www.thenaturalhome.com [Source type: General]

.It may also be used to saturate other types material such as soil to increase heat capacity.
• Adobe brick or mudbrick.^ Typical thermal mass materials include concrete, brick, masonry, tile and mortar, water, and rock or other materials with high heat capacity.
• Energy Glossary - Letter T 25 September 2009 9:53 UTC www.energy.ca.gov [Source type: Reference]

^ Salvaged materials effectively have no embodied energy other than transport and should be used whenever possible.

^ Table 6 : Volumetric heat capacity of different materials .
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

• Earth, mud, and sod. .Dirt's heat capacity depends on its density, moisture content, particle shape, temperature, and composition.^ Concrete and masonry, with their high heat capacity and density but moderate thermal conductivity offers a good balance.
• The Concrete Centre explain thermal mass: News from The Concrete Centre 25 September 2009 9:53 UTC www.buildingtalk.com [Source type: FILTERED WITH BAYES]

^ Storage rooms need to be kept dry but heat, light, and thermal capacity are of little concern, though the preference is for constant cool temperatures.

^ The specific heat capacity of most building materials is around 0,8-1 kJ/kgK. Wood has a higher heat capacity of 1,6-3 kJ/kgK, but has a relatively low density.
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

.Early settlers to Nebraska built houses with thick walls made of dirt and sod because wood, stone, and other building materials were scarce.^ Using strawbales for a permanent interior wall building material has endless problems, though: .
• Sustainable design, passive solar house HTM holistic housing consultation packages for the earthhome do-it-yourselfer. 25 September 2009 9:53 UTC www.thenaturalhome.com [Source type: General]

^ Strawbales would make fine insulation wrapped around an HTM, but don't use them for the walls' actual building material.
• Sustainable design, passive solar house HTM holistic housing consultation packages for the earthhome do-it-yourselfer. 25 September 2009 9:53 UTC www.thenaturalhome.com [Source type: General]

^ (Note that it would not be possible to have a closed house with zero insulation as all material has some insulative effect and also the air layer immediately adjacent to the wall material also has an insulative effect.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

.The extreme thickness of the walls provided some insulation, but mainly served as thermal mass, absorbing heat during the day and releasing it during the night.^ I have not adjusted insulation or thermal mass.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

^ That's the principle of thermal mass-the ability of a material to absorb and retain heat.
• Definition of Thermal mass - Blue Egg Glossary 25 September 2009 9:53 UTC www.blueegg.com [Source type: General]

^ In a structure, building materials with high thermal mass, such as concrete, brick, or tile, can absorb heat during the day and release it slowly back into the building at night, helping to keep interior temperatures constant.
• Definition of Thermal mass - Blue Egg Glossary 25 September 2009 9:53 UTC www.blueegg.com [Source type: General]

.Nowadays, people sometimes use earth sheltering around their homes for the same effect.^ At the same time the use of air-conditioning in the UK is growing by around 8% each year.
• A changing climate for thermal mass - Modern Building Services 25 September 2009 9:53 UTC www.modbs.co.uk [Source type: FILTERED WITH BAYES]

^ The powerful suction created by escaping warm air is called the stack effect, or sometimes the chimney effect because it is the same process that draws smoke up a chimney or smokestack.

.In earth sheltering, the thermal mass comes not only from the walls of the building, but from the surrounding earth that is in physical contact with the building.^ Green Building magazine : THERMAL MASS .

^ Thermal Mass Controversy in the building world.
• Thermal Mass - Associated Content - Topic - associatedcontent.com 25 September 2009 9:53 UTC www.associatedcontent.com [Source type: General]

^ Only one problem,the rest is usually 2c to high so I allow for this.If I set the thermal mass higher it predicts a higher mash in temp.
• HOMEBREW Digest #3746 Thu 27 September 2001 25 September 2009 9:53 UTC hbd.org [Source type: FILTERED WITH BAYES]

.This provides a fairly constant, moderating temperature that reduces heat flow through the adjacent wall.
• Rammed earth.^ The electronics senses this temperature reduction and adds additional power in order to maintain a constant dT. The amount of power delivered to the heated element, therefore, is just proportional to the mass flow rate.
• THERMAL MASS FLOW METER MF200 FLOW METER KR;10127102 products 25 September 2009 9:53 UTC www.alibaba.com [Source type: General]

^ For a construction material to provide a useful level of thermal mass it must have a high specific heat storage capacity, be of high density and have moderate thermal conductivity so that heat conduction is roughly in synchronisation with the daily heat flow in and out of the building.
• The Concrete Centre explain thermal mass: News from The Concrete Centre 25 September 2009 9:53 UTC www.buildingtalk.com [Source type: FILTERED WITH BAYES]

^ THERMAL BREAK (thermal barrier) -- An element of low heat conductivity placed in such a way as to reduce or prevent the flow of heat.
• Energy Glossary - Letter T 25 September 2009 9:53 UTC www.energy.ca.gov [Source type: Reference]

.Rammed earth provides excellent thermal mass because of its high density, and the high specific heat capacity of the soil used in its construction.
• Natural rocks and stones.^ Timber has a high heat capacity but a low thermal conductivity.
• The Concrete Centre explain thermal mass: News from The Concrete Centre 25 September 2009 9:53 UTC www.buildingtalk.com [Source type: FILTERED WITH BAYES]

^ Brick, concrete and stone have a high thermal capacity and are the main contributors to the thermal mass of a house.

^ For a construction material to provide a useful level of thermal mass it must have a high specific heat storage capacity, be of high density and have moderate thermal conductivity so that heat conduction is roughly in synchronisation with the daily heat flow in and out of the building.
• The Concrete Centre explain thermal mass: News from The Concrete Centre 25 September 2009 9:53 UTC www.buildingtalk.com [Source type: FILTERED WITH BAYES]

.See Stonemasonry.
• Concrete, clay bricks and other forms of masonry.^ Typical thermal mass materials include concrete, brick, masonry, tile and mortar, water, and rock or other materials with high heat capacity.
• Energy Glossary - Letter T 25 September 2009 9:53 UTC www.energy.ca.gov [Source type: Reference]

The thermal conductivity of concrete depends on its composition and curing technique. .Concretes with stones are more thermally conductive than concretes with ash, perlite, fibers, and other insulating aggregates.
• Insulating concrete forms are commonly used to provide thermal mass to building structures.^ I have not adjusted insulation or thermal mass.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

^ The use of thermal mass can do much to simplify the design of buildings and their services.
• A changing climate for thermal mass - Modern Building Services 25 September 2009 9:53 UTC www.modbs.co.uk [Source type: FILTERED WITH BAYES]

^ Green Building magazine : THERMAL MASS .

.Insulating Concrete Forms or ICF provide the specific heat capacity and mass of concrete.^ Empty cores are normally filled with concrete, sand or other material for additional thermal mass - there is no good reason to leave cores empty or filled with insulation.
• Sustainable design, passive solar house HTM holistic housing consultation packages for the earthhome do-it-yourselfer. 25 September 2009 9:53 UTC www.thenaturalhome.com [Source type: General]

^ Even concrete walls without any solar exposure are useful as thermal mass, so yes, I would recommend putting the insulation on the outside of the wall.
• Thermal Mass and Energy Storage: Questions and Answers related to the book Living Homes 25 September 2009 9:53 UTC www.hollowtop.com [Source type: General]

^ Rooms that need to be heated occasionally, such as a spare bedroom, perform better with a low thermal capacity with insulation on the inside of the room.

.Thermal Inertia of the structure is very high because the mass is insulated on both sides.
• Log is used as a building material to create the exterior, and perhaps also the interior, walls of homes.^ They have very low thermal masses.
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

^ Using strawbales for a permanent interior wall building material has endless problems, though: .
• Sustainable design, passive solar house HTM holistic housing consultation packages for the earthhome do-it-yourselfer. 25 September 2009 9:53 UTC www.thenaturalhome.com [Source type: General]

^ High thermal mass building materials allow the heating and cooling effect to be stored within the home's walls and floor (radiant).
• Sustainable design, passive solar house HTM holistic housing consultation packages for the earthhome do-it-yourselfer. 25 September 2009 9:53 UTC www.thenaturalhome.com [Source type: General]

.Log homes differ from some other construction materials listed above because solid wood has both moderate R-value (insulation) and also significant thermal mass.^ It is important to recognise that all materials have a thermal mass of some kind.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

^ I have not adjusted insulation or thermal mass.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

^ All material has some insulating effect.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

.In contrast, water, earth, rocks, and concrete all have low R-values.^ Materials such as strawbales, rubber tires, wood, carpet, logs, ICFs, autoclaved aerated concrete and drywall, all effectively resist heat loss ("R" value) , but they have very low energy storage capabilities (K value).
• Sustainable design, passive solar house HTM holistic housing consultation packages for the earthhome do-it-yourselfer. 25 September 2009 9:53 UTC www.thenaturalhome.com [Source type: General]

^ Presenting all four design elements (Earth, Air, Fire & Water) in every area is optimal.
• Sustainable design, passive solar house HTM holistic housing consultation packages for the earthhome do-it-yourselfer. 25 September 2009 9:53 UTC www.thenaturalhome.com [Source type: General]

[4]

### Seasonal energy storage

.If enough mass is used it can create a seasonal advantage.^ Another possibility to create thermal mass is the use of phase change materials.
• New4Old WP4, 4.1: technical guidelines for building designers 25 September 2009 9:53 UTC www.new4old.eu [Source type: FILTERED WITH BAYES]

^ (It may be possible to use high thermal mass in tropical or subtropical areas provided the overnight temperature got to a low enough level to provide useful coolness.
• EnergyEfficient House Design 25 September 2009 9:53 UTC home.vicnet.net.au [Source type: FILTERED WITH BAYES]

.That is it can heat in the winter and cool in the summer.^ The basic principle of sustainable, passive solar heating/cooling is that the house AND the ground around it stores heat all summer and releases it all winter.
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

^ Figure 4b: Two-story sunspace: winter, sunspace cut off from the house (Section A); winter, sunspace helps heat both stories of the house (SectionB); summer, sunspace helps cool booth stories (SectionC).
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

^ The longest wall of the house should ideally be facing due (solar) south to receive the maximum winter and minimum summer heat gains.
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

.This is sometimes called "Passive annual heat storage or PAHS". The PAHS system has been successfully used at 7000 ft.^ For example, if only 10 percent of homes in the U.S. used solar water-heating systems, we would avoid 8.4 million metric tons of carbon emissions each year.
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

^ We are not merely talking about storing heat for a few days here, this is seasonal passive solar heat storage with no "moving parts" .
• Sustainable design, passive solar house HTM holistic housing consultation packages for the earthhome do-it-yourselfer. 25 September 2009 9:53 UTC www.thenaturalhome.com [Source type: General]

^ Why pay for all that concrete and ICFs then never get a chance to "use" the heat storage?
• Sustainable design, passive solar house HTM holistic housing consultation packages for the earthhome do-it-yourselfer. 25 September 2009 9:53 UTC www.thenaturalhome.com [Source type: General]
• High Thermal Mass 25 September 2009 9:53 UTC www.sipcrete.com [Source type: FILTERED WITH BAYES]

in Colorado and in a number of homes in Montana.[citation needed]

## References

1. ^ Principles of eco-design
2. ^ Thermal Mass
3. ^ Chiras, D. The Solar House: Passive Heating and Cooling. Chelsea Green Publishing Company; 2002.
4. ^ Thermal Mass - Energy Savings Potential in Residential Buildings

• Ogdenmfg.com, Thermal conductivity and specific heat charts

# Citable sentences

Up to date as of December 16, 2010

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