All stone, tile and metal feel cold, until their temperature surpasses that of other material that feel warmer. Depending on the heat sources in your house it may feel cold, cool, medium lukewarm, or anything else. Materials that feel warm are silicone (e.g. pads), styrofoam, wood (cork especially), cloth.

Many years ago I lived in in an old homestead that time had left behind in downtown Phoenix. It had no air conditioning except for a swamp cooler in the living room, but it was quite tolerable. One reason for that was that all the food storage pantries had been lined with granite and they stayed pretty cool, even during an AZ summer.

So I'm gonna slightly disagree about it warming up to ambient temperature. Mine didn't.

We chose Corian in the end because dh liked how it did not feel cold to the touch. We keep our house at an even temp, so guess it would not have made much difference here after all. Although, we are using a programmable thermostat once the heat gets turned on again, so it may have been cold here from the cooler nights.

I was worried about this b/c we keep our 1st floor at 67 degrees during the day and 62 degrees at night during the heating months. We live in the midwest with a cold, snowy climate. Our granite is cool to the touch but not cold. I do not need a place mat (as I feared I would) at the island when I eat breakfast.

It's been a pleasant surprise. I added granite in my utility room and master bath I've been so pleased with it. We've had it almost a year.

I prefer cool feeling counter tops. Something says 'clean' about a cool surface. Same for bathroom floors and counters.

If you want to warm them, there is radiant heating available.

As pllog states it is almost 100% perfect.
As writersblock states it is almost 100% perfect.
Relative to your body temperature, it feels cold, and get this: it's the same temperature as the room air. Using thermometers you can measure this. Room temperature stone always feels cold, when the room's temperature is below body temperature. And what WAS the room air temperature in the pantry in Phoenix during an AZ summer?

As plog states it, when you touch the stone, it acts towards you as a "heat sink" (that is the technical term).

To turn it into a heat source instead of a heat sink, glue electric heating cables under your counter. Then, whatever wattage you give it will supplement the house heating and thereby allow you (if you so choose) to reduce other heaters' output by the same amount. Nothing gained nothing lost, in terms of house heating, but a big difference is made in the touch, and a good time can be had by all.

hth

soryy i meant to write plllog but didn't press the L key hard enough.

I've spent time in Phoenix in the summer, Writersblock, so I do get what you're talking about, but physics are physics. That's why they used stone insulation for the pantries to begin with. :) It sounds like they were designed well enough to keep the heat from getting to the stone. It's not the ambient temperature in the living space that the stone warms up to, but the ambient temperature in the pantry. Although some warm air comes in, air is very not-dense. I'd guess that the warm air coming into the pantry cooled down a lot faster than the stone warmed. Perhaps the stone did rise in temperature several degrees over the summer, but not enough to notice.

That does point out something I left out of my first post. In order for the granite to rise to the air temperature, not only do you have to have a constantly warm air temperature, you have to have a sufficient volume of air to dominate the density of the granite. Some kitchens have massive expanses of granite out of proportion to the volume, where, like in Writersblock's old pantries, the stone does more to cool the air than the air does to warm the stone. The big difference is that the stone is passive, whereas you can throw more energy at warming the air.

We had some positively Phoenixian temperatures last Summer. My soapstone went from its usual slightly cool to ambient. Felt like Corian (plastic), i.e., room temperature. With the heat on this Winter it is pleasantly cool, but hasn't gotten back to the bone-chilling misery that it was when it was first installed. It feels like the same cool that the cabinet doors are. I.e., ambient.

I've seen a product used to thaw frozen food: it's a little block of granite or other rock. My friend says it draws the cold out of the frozen product. Explain why?

Interesting discussion. Always wondered if I would want granite for that very reason. It seems that I am always cold in the winter!

Florantha, I have one of those old 7-8 foot long, double drainboard, castiron farmhouse sinks. I find that if I thaw my meat on one of the drainboards it thaws much quicker than if it is put on the counter. Not sure why that is either.

For the exact same reasons already explained. The frozen stuff is lower in temperature than the stone. Any stone, not just granite.

The stone is at room temperature, but it doesn't give you that feeling because it takes a little heat away from your fingertips when you touch it or come very very close to touching it. In contact with anything warmer than it, it transfers a lot of heat energy from the warmer thing into its mass. That is a transfer of cold or of heat, it doesn't matter which way you view it.

The stone is at room temperature, and in contact with the frozen stuff it transfers a lot of heat energy from its mass into the frozen stuff. Since the frozen stuff is at a lower temperature than it is, it acts as a heat source to the frozen stuff.

As plllog explained it 2.5 hours ago, it's all because it has a high "specific" heat. The amount of heat (heat energy) per mass to raise OR to lower its temperaturr is lot of heat energy. So... it puts a lot of heat into the frozen stuff, because it has a lot of heat energy stored in it although you cannot feel it.

You may think its apparent coldness means it's truly cold... but this is 100% wrong. It is at room temperature, and it a great big heat sponge, which never loses the heat, as it returns heat to all objects colder than it. Returning heat to an object is a way of saying Transfering Heat into colder objects.

Transfering Heat into colder objects = defrosting frozen stuff.

hth

>Some kitchens have massive expanses of granite out of proportion to the volume, where, like in Writersblock's old pantries, the stone does more to cool the air than the air does to warm the stone.

Yes, that's very true. That was some thick, heavy granite and it had adobe brick behind it (and being interior walls they didn't get direct sun).

David, what's a few L's between friends. :)

What you describe is the difference between cool to the touch and bone-chilling pain, and why I hate stone tiled showers. Porcelain/ceramic tile, especially glossy tile, feels equally cool to the touch, but isn't the kind of heat sink that stone is. My cabinet doors really do feel as cool as my soapstone, btw. Both heated pretty well, but 64 degrees over night.

BTW, the reason fabric (and cork!) feel so much warmer to the touch is that it is warmer! The material might not be, but there is a lot of air in there, and the air quickly levels to ambient, and warms the material at many many points, rather than only from the outside in. If you're wearing the stuff it's even warmer, at which point the air closest to you is warmed by your skin temperature, the air closest to the room is trying to be room temperature, and in between it's in between. :)

I live in MN. I have granite on my island where I also have seating. I have found it to be almost painfully cold in the winter when you lean your forearms on it. It's beautiful to look at but unpleasant to the touch in the winter. I also find myself always wanting to put a cork trivet or a magazine or something under my coffee cup if I'm having a cup of Joe while sitting there because I think the coffee will go cold in an instant. I probably would choose a different surface for an island with seating if I were to do it again - which I don't intend to do.

We do use a setback thermostat and we turn our heat down to 60 during the night and during day on weekdays. So the island never really warms up much during the week. It gets a little better on the weekends.

there once was a woman like a genie
who wore a very warm bikini
two wisps light as air
one here one there
with nothing but genie in betweenie

cork and fabric feel warm within a microsecond of contact.
By returning the body heat which they receive.

I think all these materials have the same temperature in a given environment, but they all have Different Conductivity. For the same reason you put a silver spoon in your tea or coffee to cool it down faster than if you put in a wooden spoon at the same initial temperature.

Also, a big mass of stone acts like a capacitor and stores more heat energy, then radiates it back into the environment. Soapstone or granite stores more than cast iron.

Lynn

Gibby3000,
Now why are your elbows on the table???
Just kidding, You describe exactly why I find myself
sitting at my breakfast table every day with my coffee
and newspaper. I like my elbows warm. : )
We are in cold wintry New England so (like your family)
we turn our thermostat to 60 at night. Everyone sleeps
better but in the morning it is chilly. I am just
thankful I have warm wood floors.

~boxerpups

PS. OT
Sad about the Vikings this year. DH is a HUGE vikings
fan. Where will they play? No stadium, snow issues....

You can have radiant heating mats installed under your counter. there was a recent article in Fine Home Building magazine which called an island with heating mats the "modern hearth".

Here is a link that might be useful: Fine Home Building article

All this delta-H talk is giving me the shivers.

"The stone is at room temperature, but it doesn't give you that feeling because it takes a little heat away from your fingertips when you touch it or come very very close to touching it."

It is the mass of the stone and its relatively good heat conduction that makes it appear cool.

It takes a lot of heat to change the temperature of a large mass.

Since it also conducts heat well the heat you supply by touching the stone does not warm the small areas you are in contact with, but is carried into the entire stone.

At higher temperatures from something already containing more heat (like a hot pan of food) you can create a local 'hot spot' but it dissipates quickly once the source of heat is removed (and also cools the pan quickly since the stone has a lot of mass to absorb heat).

A large block of metal behaves the same way, and have been sold to speed up the thawing of frozen food.

Corian and other material have enough adhesive in them to slow the movement of heat into the object (and a lower mass also).

Your touch quickly raises the temperature under your finger higher so the surface no longer feels cool.

The granite is at room temperature, but it takes a large amount of heat to change the temperature of the granite.

All very interesting. Thank you for the explanations.

I think I would like to have some kind of stone on my work table, for baking. Marble would be nice, or even engineered marble, if it's easier to maintain.

However, on the perimeter cabinets, I would rather have something a little warmer. It's so cold here in the winter, I think a warmer surface would be more welcoming :)

more good ways to say it.

Heat wires can be glued. (They don't need to be thinset). I've seen this done, by professionals.

I have direct access to the quartz's underside, in my kitchen, because I did not install any plywood underneath. I can have heat cables in contact with my quartz. I can install the cables after the fact, as a retrofit, and adjust their spacing. This is one more advantage to eliminating the plywood layer.

curmudgeon mode on... I think it's absurd to use energy from a coal-fired powerplants or tanker-hauled oil or water-intensive natural gas to heat up countertops. If your electricity is home-generated by wind or sun, use it any way you like, but if it's generated by a fossil fuel don't be an ugly American. God gave you different substances to use for your eating and schmoozing areas and hopes that you will use them.
curmudeon mode off...sorry Lavendar...and Miss Manners...

Florantha,

Did I forget to tell you, You are great!!!!
We all need a little cromudgeon to keep our
planet healthy and our TKO in check.

~boxerpup

Florantha- I was thinking the same thing! LOL At least we have water power (thanks to the Columbia River) but I still wouldn't use it to heat my countertop :)

Florantha,

I agree with you but the once the flood gates of design, products, need and want are opened, there is no stopping them

First it was heated bathroom floors, next it will be heated countertops. Comfort is a strange beast. It is never enough. we need more and more and more ;)

At least the economic situation is making us all a little more humble.

About 24 hours ago I posted ".... whatever wattage you give it will supplement the house heating and thereby allow you ... to reduce other heaters' output by the same amount. Nothing gained nothing lost, in terms of house heating..."

Hope this is clear.

Repeat: There is no waste in heating the countertop.

Repeat: Using the countertop to act as a radiator (radiating heat) is smart not dumb, efficient not wasteful.

All clear now?

Of course you are entitled to have a different initial reaction when you read about heated countertops for the first time. Give it some thought and get back to me when you've got it a bit more figured out.

hth

Farmgirlinky wins the physics home test. While the stone may not be exactly at the air temperature at any given time due to its thermal mass and the rate that air can warm or cool it, thermal conductivity influences how "cold" it feels.

A room temperature copper, silver, gold, diamond, or sapphire block, to name a few materials with high thermal conductivity, even if not usually granite slab sized, would feel even colder than the granite when at the same temperature. And because the granite thermal conductivity is a bit higher than that of the soapstone, it also feels a bit cooler than soapstone when touched by a finger that is warmer.

kas

David- Are you heating the cabinets the same way you're heating the house? Are the rates the same?

I think it was more a question of the costs involved with installation. So many luxuries end up being necessities, it's probably the beginning of another trend.

Basic problem with economics...how do you stretch limited resources to meet unlimited wants? Do you ever limit the wants...or continue to try to stretch the resources? When that's not possible anymore, do you allocate resources through monetary means, political clout, social standing, etc.? Or do we ever realize that we can voluntarily limit some of our wants, reuse, recycle, or even do without a few things, if it means our resources will last a little longer?

Hi Florantha, I suppose if we are as concerned about the planet as we should be, we had better cease and desist with all our luxurious home renovations! Consider the consumption of fuel to transport the workers and materials, and to manufacture the steel and ship the stone and, and, and....But if it helps to think of it this way: it is very efficient to radiate heat from something you are in contact with, such as the floor or granite countertops, rather than to heat up the air in the room around you, and so it can save fuel. There is no moral or ecological difference between radiating heat from the kitchen counter (if, say, the electricity to do that comes from a gas-fired plant) or radiating it from a gas-fired hot-water radiator, and it might be more efficient.

Lynn

Renovations are not always eco friendly.

I wound up with new appliances that are far more energy
efficient. I even received a Gov. rebate for my
refrigerator. We had to put in a new furnace put in and my
heating bill has dropped down to half. Yes, half!!! I had
no idea how much fuel we were wasting with the old furnace.
We put in better insulation, used cork, Bamboo, PureBond
Plywood, and even reduced our overall waste in the
project. DH wired our lighting, speakers and outlets with
a goal toward being more efficient. Our lights all use
fluorescent bulbs. DH created a super recycle trash system
so that everything from glass, tin, paper, plastics.. are
recycled.

I wish I could be more like Ed Begley Jr. For now I am
willing to make serious changes for the planet while
creating a pretty kitchen.

~boxer

Electricity is not generally a good way to generate heat either from an efficiency or from an economic standpoint, although I'm sure some of you can find ways to make me wrong here.

What Davidrol is saying is that once the thermal mass of an object is heated, the item will radiate heat into the room if the room is cooler. Put another way, once you introduce a mass that is hard to heat up, it also takes time to cool off. This is the principle in my solar porch, in which dark colored tile absorbs sun in winter and exhales heat into the room after sundown. It is also true that the room is almost insufferably hot on a sunny February day after the point where the air temp has no more cold mass to pass off the heat into. We usually turn on the ceiling fan and the furnace blower to dissipate the air heat until it's at a moderate temp. When there's no sun, we shut the curtains and wear shoes in there to keep the feet warm.

If I recall the physics correctly, it's more comfortable to keep the ambient air and the objects in the room generally at same temp as much as possible; when there is a rise and fall, it throws the greater system out of whack, at least for a while and the room will feel cold even if the air is at "normal air temp" for the season. Although I am unfamiliar with countertop heating, I would guess that the stone will feel cold until it approaches the temp of the fingers and arms, which I would guess are give or take about 90 degrees Fahrenheit--not as hot as the body core. So let's say that you have a 5 foot by 3 foot by 2.5 inches granite island to heat. Will you heat it continuously or only the hours before you plan to sit at the counter? what temp will you keep it at? At what point will it begin to exhale heat into your room? And what will it be like when the warmth of the stone is sufficient to affect the ambient air in the room? Like the tile at the community pool?

If the heater remained in the on position for days, do you strip down to shirtsleeves or even less in February as I do when I'm in the solar room? Do you allow the kitchen to disconnect from the whole-house heating system so the distant rooms continue to receive heat or do you let the rest of the house cool down when the countertop is in heat mode? Or is the heat of the stone mass of that island not that big a deal, meaning that it really doesn't affect the room heating and house heating very much. In which case, we're back to the question of whether you're using the counter for heating or for comfort and putting those hydrocarbons into the atmosphere whenever you flip the on switch. If the granite really performs well as a heat radiator, it belongs at the floor level, not halfway to the ceiling and it should be heated with the most efficient and planet-friendly method as possible.

I recently wrote about spending a morning next to the window in a local restaurant that has granite topped cafe tables. I had to put on my jacket even though the room was warm. I definitely won't go back there again. Laminates, some stones, and wood are more comfortable.

And what do you do about granite in a sitting area in the air conditioning season? Leave the auxiliary heat turned off?

Florantha,

I wanted to mention that I ... ahem.. actually have a section of heated countertop. Ignoring a fight over using different types of energy sources I can give you my reasoning for it and that may provide fodder for more conversation.

It's a strip of 1 foot by 4 feet that is the upper level of the bilevel island that houses my cooking surface. So four feet total.

From previous experience I knew that I am not skilled at getting every dish to come to completion on time and therefore had a hard time keeping them ready until it was time to eat. On the other side of that coin I didn't want to continue to waste cooktop space with dishes that were mellowing so the landing space needed to be able to accept hot dishes from the cooktop without sucking all the heat out of them. These problems were accentuated by the fact that I too prefer to keep a cool house for energy conservation purposes which leads to a third issue: Much of the time I am unloading hot dishes such as pasta into cold bowls so that it immediately congeals into gross lumpy paste.

So I ended up with that 4' or so of raised counter that has an electrical web below it. That will warm the bowls/plates I am using for the meal and allow me to stash completed dishes without cooling them down and without worrying about the hot pans burning or damaging the surface.

There may have been a more economical way to have done this but I spent a long, long time looking at it. Other options were to heat the whole house to a higher temperature so that the heat drain wasn't as severe, to use the oven to preheat the dishes, etc and I found that this concept seemed the most limited, most value specific way of getting what I needed for the space.

The idea is that if I turn it on when I begin dinner, placing a few of the dishes to be warmed on it at the time, by the time I am looking to use those dishes they will be warmed up and ready to be served into.

The total cost of the project was a ctop material that would have been purchased anyway and about 15 dollars worth of electrical wire. The total draw of electricity, or so I'm told is in line with about two? extra lights during the period I have it on, possibly less. Further, I live in Portland and pay a premium on my electric bill each month to support the generation of green power.

None of these things mean that I'm not using electricity to, in essence, heat my home. But in this specific example I DO believe that my solution is the greenest way to achieve what I was looking for: Warm food and a safe kitchen environment.

I agree with you on the basic concept of a consumer heavy society however I only cautiously reject a new type of use for technology. I feel each use needs to be examined on it's on merits.

I like to think about how we use thermal mass to moderate the temperature of a home when I am trying to explain why the stone in our homes fees cold. Some people will have a large amount of stone, concrete or brick built into a home, especially if the home is situated to take advantage of the sun's afternoon heat.

During cold times of the year, the afternoon sun comes through the glass windows in the home, where it falls onto the stone mass. The sun hits the cooler rock and warms it. In the night, when the air temperature falls, the stone gives up its "stored" heat. This is a natural process. More massive objects "store" heat because they take longer to change temperature. The rock stores the heat of the afternoon. At night, when the air is cooler, the warmer stone "gives out" its heat, slowly. Because it has a lower mass, air switches temperature very quickly. Rock lags way behind the air temperature change. Because of that, the stone "heats up" the cooler night air. When it does that, the stone becomes cooler. So when morning comes and the day heats up, the stone is lagging behind and now "cools" the warm house. Stone feels cool compared to the now warm air. Where the stone and air meets, on the surface of the stone, a heat exchange takes place. The stone is now cool from the lower night temperature. Through the afternoon, the stone gets warmer and warmer, then after the sun is gone, it starts the slow process of returning the heat back to the air.

By always lagging hours behind the air temperature change, the rock temperature change keeps the air in the home from getting as extremely cold at night or as extremely hot in the day. The thermal mass is used to take the big swings out of the air temperature in the home, keeping it a little warmer at night and a little cooler in the afternoon.

I think of it like this: a massive elephant does not reverse direction quickly. It takes a while to slow down, then to stop, then to turn and then speed up again going in the other direction. Thermal mass is the same way. Using thermal mass and exposure to the warm day's sun, the rock in our homes evens out the cycles of heat and cold. The dips are not as low as they would have been, and the highs are not as high.

Nancy, do you think this effect would work for a stone terrace in front of south-facing windows as well as it does for a masonry wall at the back of a south-facing room? Or in the long run will a stone terrace situated between the room and the sun mean that, in summer, the south-facing room can't cool off at night and the next day becomes hotter than it otherwise would? What is your priority in Michigan: reducing heat gain, or minimizing heat loss? In Connecticut (zone 6) we have both concerns.
Lynn

My granite is not cold to the touch either in the kitchen or in the bathrooms. Our house is kept at 68-70 F. during the day (depending on the weather) and 62 F. at night. I did notice that at a Home Depot where they had kitchen mock-ups set up that silestone/ceasarstone was much cooler to the touch than granite.
Now in terms of heating pads - we didn't put them in our bathrooms which I don't miss but we have slate in our front entrance (which is a basement entry) and I wish we had though to put heating under the floor there. It would have warmed up the front entrance and the heat would have gone up the stairs to our living area.

does this have effect on perhaps why new pyrex shatters directly from oven to stone countertop?