Adding Slab to existing concrete basement floor

[I Stand Alone]

I am looking into storage options and thought for efficiency of space that a slab on top of my existing concrete floor may be an option. Ceiling height is not a problem and the basement is completely unfinished, ran out of money once the house was completely remodeled!

Any suggestions on design. The floor is 28' x 36'

Thanks

I Stand Alone

 

[webie]

I am confused ? What does adding a slab have to do with storage ?

 

[I Stand Alone]

The concrete slab as storage. Using radiant tubing in the slab I could use it for storage. I have a econuburn 150 and need storage to stop the idling time

 

[webie]

The concept might be good but it wont work as you think it will . First I think my concrete guys said the max injection temperature I believe is 130 degrees , but the max I think I read that you should do is a 40 degree difference in slab actual temp verses water temp . My heating guy says for me to max out my mixer at 110 to be on the safe side . Using mass for storage really doesn't work as you have no control over it . Once it is hot you have no control over the heat dissipating from it . As far as radiant in slab it works because of the large surface area and continual heat out put . Your basement still will only require so many BTU's to heat all the slab does is buffer out the highs and the lows . Its not really designed for mass storage.
If you have a large open basement why don't you put in a insulated storage tank so as to store excess heat for use later .

 

[Floydian]

I agree with webie.

Here are some quick numbers to think about:

specific heat of concrete= .2 btus/lb/degree F

28'x36'x4" slab=12 yds of concrete=48,000 lbs.
48000x.2=9600 btus/degree F
Assuming you'd be comfortable with a 10 degree F temp swing in the slab, that's 96,000 btus stored.

specific heat of water=1 btu/lb/degree F

250 gal. of water=2085 lbs or 2085 btus/degree F
Assuming a 50 degree F delta T in the tank (180*-130*)=104,250 btus stored.

NOTE: all numbers subject to error.

A storage tank should come in far below the cost of a slab. If you could squeeze in 500 or more gallons of storage you could gain some convenience that the slab just cant really give you.

Good luck,
Noah

 

[Frozen Canuck]

Agree with the above advise. Think of a slab like a train, very slow to gain speed (heat) very slow to cool down. Storage will give you far more comfort & satisfaction at far less cost. It will also solve your idling issues provided you install enough.

 

[Reggie Dunlap]

You said headroom isn't an issue, but you'll need at least 2 inches of foam under the slab for a total of 6 inches. At the very least you'll have to re-frame the stairs, and if there are any windows they are going to be pretty low.