What design would fare a unoccupied winter freeze better?
I want to do some RVing during the winter and wondered how much energy my design might consume while I was away for a few of the coldest months.. Or better said, which basement design would not require any heat to survive the coldest months in northern zone 5 Iowa?
In general, would a design with a insulated basement stand a better chance of not freezing up? Or leave the floor uninsulated since we know it will remain 50 degrees? The proximity of the water pipes to a outside wall might have more of a effect..
Would I be better off with a frost protected slab on grade with centrally located water supply, when also considering potential foundation damage during a long freeze?
Would my time be better spent plumbing in drain valves to everything watching pitch, and wiring heat tape to the P traps etc? Or last, simply leave the heat set to 35 degrees?
Thanks
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Insulate your basement walls. Use rope caulk on windows if you have any draft at all. Set your heat to 50F. DO NOT set your heat for 35F — you will be below freezing in parts of your house if you do that because the temperature you set your thermostat at is NOT the same as the temperature every part of your house will actually be held at. You need some wiggle room.
You could try draining your pipes, but unless your house was plumbed to allow for that to work it’s unlikely you’ll ever actually get all the water out without blowing the system out with compressed air. Even with compressed air you have to be careful (I do this ever year in a cabin). Shutting off your main water valve when you’re away will help to limit the damage if you do have any pipe freeze issues. Shutting off unneeded electrical circuits can also be useful.
If you’ll be away for extended periods of time, I recommend getting a Sensaphone or similar to monitor your home’s temperature and power, and possibly water on your basement floor. These devices can call your phone to tell you if there are any problems that require your attention.
Bill
Mike,
Your main goal should be to design the water supply so it can be drained to a point where the shut-off is protected from freezing. I wouldn't rely on the house maintaining sufficient temperature by coupling it to the ground to keep the war supply warm en0ugh.
There is a small chance with a full basement that the temperature in the house could drop until your foundation was damaged. That wouldn't be so with a FPSF which doesn't rely on the heat above to keep the ground from freezing.
You may find this article useful: https://www.greenbuildingadvisor.com/article/can-buildings-take-vacation-too-part-ii
There are some frost protected shallow foundations that are safe with no heat.
> since we know it will remain 50 degrees?
This is one of those absolutely not true building science myths.
The house I bought was empty most winters with purpose built plumbing for draining it all in the basement. They set up dampers to shut off most of the upstairs heat, except near the thermostat. Drain the water and water heater, antifreeze the toilets, keep the basement at 40 or above (lowest the thermostat will go), and turn off the well pump seems, to have worked. If only they had air sealed and insulated like they cared.
Thanks everyone.
It sounds like a frost protected slab on grade, and providing water drains is the better choice and approach when concerned with unoccupied freeze up. I would hate to have a full basement concrete wall failure just because of my snowbirding adventures. But I would still need some sort of a tornado shelter.
Mike