Question: I'm considering a passive solar radiant heating installation in the Chicago area and was wondering if it would be feasible to store enough water/energy to support heating for most of the night. The house already has a gas central furnace, and can serve as backup, but the winter bills have been as high as $300-400 (for about 300 to 400 therms) during last year's expensive gas rates. 

Roughly how much water might be needed to keep ~2000 sqft heated when it's 0 outside overnight in a below average insulated house? Orders of magnitude would be good enough of an estimate. I'm really just looking to understand if this is feasible. If this would require a basement swimming pool, obviously it's not.

Also, since the PEX would be installed on the unfinished basement ceiling, I'm a bit concerned about the basement heating up too much. I assume there are ways to shield the basement from the radiant heat via some form of heat reflectors under the PEX?

Answer: 
If I were doing this, I'd use a hole saw with a portable drill press.

![Small hole saw](https://i.stack.imgur.com/Nj56h.jpg)

![Portable drill press](https://i.stack.imgur.com/FwXpG.jpg)

If the hole saw leaves a rough hole, you can follow up with a larger forstner bit.

![Forstner bit](https://i.stack.imgur.com/06izdm.jpg)

Then fill the holes with plugs. You can make them with a plug cutter, but they're cheap to buy online.
Grip Pliers (Vice Grip) to clamp the tip of the screw and unscrew. Thats what I would do. unless the head will get stuck as its going out the other end. 

You will need to clamp the head parallel to the board so that you can get maximum torque. 
![enter image description here](https://i.stack.imgur.com/Cjdio.jpg)