Warming greenhouse soil in raised beds

[Jeremy]

I'm in coastal Virginia. I have a 8x16 hoop house with (3) 8'x3' raised beds(10" off ground). Here's what I'm wanting to do....note I've never tried winter gardening before, so any advise would be GREATLY appreciated. I will build a 2'x7' solar water collector. Pipe this via 1/2" PEX pipe throughout the raised beds and back to the water collector pumped by a low pressure solar powered water pump. This should produce approx 100 degree water through the soil all day. At night, have a small space heater to auto turn on at sunset with a photovoltaic sensor. Will my hot water pipes in the soil be sufficient to produce heat for the plants? Will this heated soil give off enough ambient heat in the air so as not to damage the plant/leaves? Any advice appreciated.

 

[Chuck]

What are your expected low temps. At first glance it seems a little over engineered. What you really should be worried about is the amount of sunlight. Without adequate sunlight nothing will grow properly no matter how warm it is. Make sure you can utilize all available sunlight first

 

[CanadianLori]

I have played with this on a smaller scale. Your theory is good because as soon as the sun sets the water stops circulating and leaves the warm water in the beds.

Your profile doesn't note your zone and I'm too lazy to look up your state's winter lows. That's the big factor here. Alternately for night heat, you can run a waterbed heater under a container of water and then run a pump to circulate at night. Solar panel to run the pump during the day and another to charge a battery for use at night.

I walked away from this because my greenhouses are much smaller than yours.

my water in a pvc rad style collector got up to 155f during the day using slower water movement via thermal induction.

Was fun playing with this stuff.

I now use a gas heater for one and have a kerosene heater for the other. Our temps drop below freezing from november hrough to the middle of april sometimes so I quit heating in December and don't start up again until march ... unless I get antsy!

Welcome to the forum!

 

[Jeremy]

Thanks for the replies. The low temps here are typically in the upper 20s-low30s, though we do dip into the single digits in jan-feb. my greenhouse gets full sun for about 6 hrs/day.

 

[CanadianLori]

You don't really have much of an issue if your night lows are hovering around the 30's so your plans would probably be super effective.

 

[Becky]

Hello! Just wanted to say welcome to the forum