Oh Garyyyyyyyyyy, how I would love to be at 37°F. We are at 15°F.

Hi Gary
The chill factor of that wind probably made a huge difference.
I bet if it were a still but cold night you would have faired a lot better.

Hopefully your system just needs a few tweaks here and there :)

Wind chill -16 this morning. Actual temp 2f
37 would be a heat wave.

It was -1 with a wind chill factor around -18 at around 3 am here. According to the remote in the house, the GH was 72.01, which confused me, as even with it being mounted with extra insulation behind it, the sensor is mounted on the north wall (actually, NE) and usually reads a tad less than the actual ambient.

My confusion ended when I bundled up to go to see for myself, and the wind hit me from the SW. The thermometer mounted on the back (SW) wall read 71 deg., while the one hanging from the ceiling in the center read 72.

The truly ultimate test of course, will come with the gas bill. I can't meter the gas being used by the GH heater, but we know pretty well how many BTU's we use in the house in the months of deep cold, so should be able to calculate the GH use with reasonable accuracy.

If we really did it right, and I'm hoping we did- it would prove to me at least, that Nathan was right. Given enough of the right type of insulation, installed where it's most effective and with a fuel effecient heater; a freestanding GH can be kept at comfortable shirtsleeves temps through the coldest weather, without breaking the bank on fuel bills.

Hex
Don't you think after "tweaking "for 20 years I'd have arrived by now ??lol At least it didn't work during the night and get to 140 the next day as happened before lol That was my most spectacular failure lol.
Birdwidow . Don't be too smug just yet with oil hitting a 100 dollars a barrel. How can ANYTHING hold stable let alone get cheaper?? I'm glad I'm an old man imagine what things will cost in a few years??
Oh well the low for tonight is 51 and back to the heat provided by ma nature lol Looks like we'll be running the air by Sat lol gary

Hi Gary
hehe 20 years? I`ve been at my own gh project for a tad over 2 years, maybe you need a different drawing board? :)

I designed mine from the ground up and in theory at least it should perform quite well (famous last words!)
i`ll let you know this time next winter :)

I`m in agreement that anything reliant on oil for heating is going to be doomed eventually.
In the short term though, any design features that help cut consumption even by a small fraction are certainly worth the effort.

Hex
The main problem has been heat but usually not too much
as long as the air flow is strong. Generally Ma Nature provides that .So generally speaking I need a structure that will alter the climate for about 5 days a year 2 weeks tops. The really tough part has been the covering. Everything I've used has had serious drawbacks in fact downright harmful !! lol. This last time I went back to only using lattice on the roof . Shadecloth and shadescreen were only short term solutions. Regular coverings are a disaster.
The local zoo built a GH and they used polarized glass
but they must run the air over 200 days a year!! I will admit that it's foolproof. It is never too hot nor cold But can you imagine the operating expense.??
In my case I used around 1200 gallons of heated water of course the open roof allows the heat to escape which is always good the next day after a front except in the present case!! lol. I felt sure 2400 watts would be enough .
Worked great until the temps fell below 40.lol Temps below 40 only happen about 10 hours every 5 years.
So the problem is how to provide for that wihout hidering the main problem heat!! lol
I checked the record for jan 3 was 31 , 1891 record high was 92 in 1980 lol. The low last year was 42 while the high was 91 lol. So any heating system can go years without
use at all while a cooling system is generally not required.
Most people just move the plants indoors for these rare times. Works great until you get several 100 plants lol
Was hoping to come up with a plan to handle anything mother nature dishes out without over doing it.
I can always use insulation to keep the water warm but was hoping the warm water would modify the air also.
Maybe more watts!!! lol.
As to oil if people will actually pay that much ,how much will they pay for gas or electricity?? Have often heard 100 is the magic price it can not go higher. I guess we'll find out lol gary

Hi Gary
The energy prices have been rising steadily for quite a few years over here.
I`ve no clue what gas and electricity cost over your side of the world but as a rough guide our electricity is about $0.20 per kw/hr and gas comes in at about $3.05 per therm (100,000 btu).
If it`s anything close to petrol price difference..it`ll be a huge amount :)
Definitely a good incentive to look for ways to save energy.

Your 1200 gallons should sink about 3kw of heat per deg F temperature rise, so i guess 90kw of stored heat (or cooling power) could be a max assuming a 30F swing.
Maybe you could dig up the yard and sink some perforated drainage tubes for a summer cooling heatsink?
If you wanted to pull the heat back out in winter you`d have to insulate above them which could get expensive.

The suns heat costs nothing and there`s usually plenty of dirt available :)

Gary: We spent an entire season and exhausted ourselves in the labor of constructing and insulating my GH foundation in order to give it every possible protection from the cold. But before we even started, I came here for advice and after weeks of debate, was finally won over by what I thought seemed the most rational and took Nathan's counsel. So if anyone could be smug with an "I told you so!" it would be Nathan. He led- I only followed.

We heat with nat. gas, not oil, but I agree that the cost of all energy will continue to rise. That's why it's so important to construct to use as little of it as possible, starting with tight insulation in the right places for the greatest effectiveness, coupled with energy effecient heating/cooling devices, regardless if they are active, passive or, most realistically for the technology currently available to average homeowners; a combination of both.

However, the type of system that you can employ in Florida simply won't work in the deep hard freezes of No. Illinois. Each region and climate has it's own special conditions and each GH owner their own special desires for their own GH use.

I wanted a GH I could use year round, keeping it close to the same temps as a basement laundry room that had become so crowded with plants and fish tanks I couldn't keep up with the laundry, so something had to go. Although I'm nowhere near as dedicated a gardener as most people here, I do love to putter with plants, so my solution was a GH in which I could keep both plants and fish regardless of the weather, and by following Nathan's directions for the foundation and wall insulation necessary for MY use in MY climate- it worked- just as he said it would.

Now Gary: will you please go over to the Aquarium forum, and answer my question about garden soil in fish tanks? You have apparently solved an aquatic plant problem and I really would like to learn how you did it.

hex
Thanks for the suggestions. Have alredy tried those lol
They failed for different reasons. I keep fish and plants in my water tanks so can't heat above 85. Obviously I'm going to have to make a choice either keep hot water tanks or insulate them and find another system to heat the air . This was an unusual cold snap in that it dropped to 35 but had 25 MPH winds.it stayed below 57 the next day and rained!! Today the low was 62 making me glad once again that there is no covering on the SH lol One of my most spectacularly failures was using plastic to cover the Sh dropped that night to a record 27. Went to work feeling smug that it was a toasty 65 inside. When I came home from work the SH was 140 inside while outside it was 75 lol. Only things I lost were inside the SH lol
If I had my "ideals I'd like the structure between 45 /85 year around with nightime drops of 15 degrees year around. Without buying stock in the power co. lol.
This go around looks like the only things damaged were those I" protected" lol For entirely different reasons.
In another 30 years I'll have a system that handles what really happens?? lol My daughter who lives in Kansas was sitting in the dark with no electricity at 13 degrees
while ice was tearing off the roof offered no suggestions at all!!! Thanks again!!
Birdwidow Have read your post and was thinking of suggestions. Believe it or not top soil did NOT solve all the problem lol This is my first attempt to keep a tank in natural sunlight as well as using the top soil.
Will write some more on the Aquariums forum .Sounds like an interesting idea!! gary

37* should not harm your plants even with wind. It may cause temporary stunting or slow-down for some very sensitive tropicals but it should not cause permanent damage. I usually don't heat the greenhouse unless temps are predicted below 35* and I grow lots of potted tropical hibiscus and 3 types of citrus.

I worked part time at a place called the Willowtree Greenhouse here a few years back. The owners never let the GHs drop that low. They believed tropical plants suffer damage at temps below 40 - 45F for any length of time. They kept their GHs, which were huge, around 55F at night. Perhaps some tropicals can tolerate more cold than others.

My Rion is at 60 to 62 (thermostats from KKontrols are great. I just ordered another one) and the HFGH, waiting for it's control, is from 50 to 59. The cheap electric heaters have really bad thermostats on them. It'll be set at 50 when the new therm' gets here. The begonias, cactus and geraniums don't mind 50F.

Hi
Damaging lows are always a great debate here in florida.
IME anything above frost is tolerable to a wide range of tropical plants. Obviously a freeze would cause breakdown of tissue. Even temperate plants will not tolerate that lol.
The hard part of the debate is while I know it's not fatal, it's certainly not ideal.. Does this mean they will not grow and flower as well as those not exposed?? Mostly the debate is around epi orchids . In some cases I can see some species seem invigorated by the cold even flower better than usual. Many other plants seem far more cold sensitive. As a family Gesneriads. some species of understory palms. Have had these types go into a tailspin at 40!! Many other species will handle well into freezing temps. Again IMOE have had far more problems with heat related stress. Thant seems generally to be mid nineties.
Again all this depends on duration,humidity, species and on and on.
In this zone a heating system is generally a total waste. The tough part is that while it can drop into the 30's (record low is 27) it usually jumps in the 70's the next day. Record duration of 32 here is 4 hours. So it's quite possible to have too cold and too hot within hours!! lol. The last cold front was very unusual in that it was windy and wet. Daytime high was only 52 and very overcast.
Have never seen that before lol.
Was so hoping that keeping the water warm(no problem) would also keep the air warm without blocking the air.
Wind was a great factor in what happened which I had not counted on was much cooler the next day and did not last 3 days as usual.
I really wouldn't mind spending the money but want a system that works or at least is not harmful lol.
Many ,many people have told me you can't build a working GH in 10 besides you don't need one!! lol thanks gary