Greenhouse Heating Options

[FourOaks]

Originally Posted by Cole_Robbie

I'm out of space now, and of course the weather has turned unseasonable cold, with lows right around freezing for several nights this week. I bought a diesel/kerosene salamander/job site heater last fall. I have problems with it shutting off, so I put it on a timer, and that helped a little. But I can tell from the fuel consumption that it is not running enough. So I just now built a fresh air intake for the heater, which is a blower connected to a wall so that it draws in fresh air. The idea of pulling in cold air into a structure I am trying to heat is counter intuitive, but if it keeps the heater running, then it will more than compensate for the cold air it draws in.

I am probably going to have to stay up and watch it. If the heater shuts off and the blower continues to run, that would be bad.

Cole, before I bought the Thermablaster Heaters, I was going to buy a Propane Forced Air Heater, cousin to your Kerosene Heater. But naturally, by that point most retail locations were already sending back stock to make room for spring and summer goods. Thats why I had to get what I got, but at least I got a good price on them.


Meanwhile....


I know of a small nursery business that uses the forced air heaters in their tunnels. So, they definitely work. But I think moving the heater outdoors, with it blowing into some ductwork would give you better results. I know they say specifically to NOT do that, but whats the worse that can happen?


Or maybe, prop open a door, placing the heater right there, then some scrap plastic to help seal the opening?

[Cole_Robbie]

Originally Posted by FourOaks

Or maybe, prop open a door, placing the heater right there, then some scrap plastic to help seal the opening?

That's what I did for last night. It ran fine when I tested it at about 11 pm. I hooked up the timer and left it. I will be able to tell from fuel consumption if it ran as programmed.


edit: oh I hooked up the timer, all right....and then didn't plug the cord into the timer, so the heater didn't run all night. Low was 32 for several hours, but clear sky. Almost all my stuff is now freeze-nipped, especially what I was going to take to market next week. Nothing is dead, but a lot of it is damaged enough to where no one will buy it, which is worse than being dead, continuing to take up time, money, space, and a lot of wasted effort.

[AKmark]

In my area nothing can beat natural gas price wise, and I use a bunch of it. LOL Some days 2 million BTU's an hour. If you want to do it right, buy a natural gas heater, vent it, and use circulating fans to blow the air around your GH. Set your t stat on 62, and you should have some incredibly healthy happy starts. Just my two cents, this is how we do it in the far north, where it is very cold sometimes.

[FourOaks]

Originally Posted by AKmark

In my area nothing can beat natural gas price wise, and I use a bunch of it. LOL Some days 2 million BTU's an hour. If you want to do it right, buy a natural gas heater, vent it, and use circulating fans to blow the air around your GH. Set your t stat on 62, and you should have some incredibly healthy happy starts. Just my two cents, this is how we do it in the far north, where it is very cold sometimes.

2 Million BTUs! I have a 2.5 ton natural gas furnace on my house blowing around 100,000 BTUS. I know how much that costs. I couldnt imagine 20 times that amount. Maybe they would give me a price break?


Seriously though, I do run a fan at the peak of the seedling house on a really low speed. My thoughts are that it should help to circulate the air a bit.

[FourOaks]

Originally Posted by Cole_Robbie

That's what I did for last night. It ran fine when I tested it at about 11 pm. I hooked up the timer and left it. I will be able to tell from fuel consumption if it ran as programmed.


edit: oh I hooked up the timer, all right....and then didn't plug the cord into the timer, so the heater didn't run all night. Low was 32 for several hours, but clear sky. Almost all my stuff is now freeze-nipped, especially what I was going to take to market next week. Nothing is dead, but a lot of it is damaged enough to where no one will buy it, which is worse than being dead, continuing to take up time, money, space, and a lot of wasted effort.

Cole.. just saw your update. Dont fret, my stuff was looking absolutely horrible. Once the temps went back up, and we started getting sunshine, they have come out of it. Most stuff anyways. I have just a few flats that I will probably toss. Not bad out of roughly 200 or so.


On another note, I was surprised last week at my Market. I sold quite a few plants that had cold damage. I explained the damage, and the customers didnt mind at all. I was shocked.

[BigVanVader]

I'm probably going to build a passive solar greenhouse. I can't see ever overcoming a huge heat bill in sales. I can get 50 gallon drums for free and can build the frame with 2x4s. Just something long and skinny I can fit about 50 flats in. That would get me through the early season.

[AlittleSalt]

FourOaks, I'm glad to read that most of your plants are looking better, and they are selling. I do wish I could have offered helpful info for you.

If I had a greenhouse here in this part of Texas - I would need heaters and an air conditioner.

[FourOaks]

Originally Posted by BigVanVader

I'm probably going to build a passive solar greenhouse. I can't see ever overcoming a huge heat bill in sales. I can get 50 gallon drums for free and can build the frame with 2x4s. Just something long and skinny I can fit about 50 flats in. That would get me through the early season.

Just 50 flats? You know what they say about building a bigger greenhouse then what you think you need.


If you do this, please do post any and all results. Im really curious about the water barrel designs. I have researched them and understand the pros and cons. For instance, lack of Sunshine. Without it, they dont heat up. For us, the month of March was absolutely horrible. I have never seen so many gray overcast days. We would have 1 sunny day a week. It was that bad.


As far as overcoming the cost of heat. I think the strategy is to cram as much as possible in the GH, to maximize the profit. I need to go over my receipts and see where I stand on propane purchases.

Originally Posted by AlittleSalt

FourOaks, I'm glad to read that most of your plants are looking better, and they are selling. I do wish I could have offered helpful info for you.

If I had a greenhouse here in this part of Texas - I would need heaters and an air conditioner.

Oh believe me, they get hot here too. The other day the seedling house got upto 115 degrees. I finally decided to roll up the plastic.

[FourOaks]

While Im thinking about it, some observations.


I probably should write this down somewhere, but I took note of some cold damage hardiness. Some stuff just took it better then others. Which is really no surprise. Most of the damage was brown crispy leaves. Most plants went into a state of dormancy. Now the weather is getting better, most plants have new growth and are turning nice and green.


Tomatoes - Most varieties showed signs, and slowed down in growth. To the point of looking dormant. Interestingly the variety "Aunt Rubys German Green" never showed any signs of damage. Just slowed down. Maybe it has cold hardiness?? The worst was "Large Red Cherry". Most have never recovered.


Peppers - Very similar to the Tomatoes, and are finally starting to come out it. The worst was Jalapenos. The best, Cal-wonder. edit: Actually the worst is a toss up between Poblano and Anaheim. They might just be trashed. Maybe not. Kinda curious what the end result will be.


Eggplant - Only started "Stars and Stripes". Will probably be trashed.


Artichokes - Imperial Star is the only variety, and they cruised thru the cold like it was nothing. These also sold at the Farmers Market like Hotcakes. Next year, Im going to start a lot more. Thats for sure.


Herbs - Sage, Oregano, Parsley, Thyme all slowed down. The Oregano and Sage showed some crispy leaves, thats about it. Basil slowed but the true leaves never showed signs. Which surprises me, based on everything I read about Basil hating the cold.


Lettuces and Cabbages no damage.


Snap Peas in the raised beds took forever to sprout. But they are growing now. My main concern is that it will get hot before they produce. So now I have a race on my hands.


Sunflowers - No damage whatsoever. Just slowed down.


Stock - No damage.


Dahlias - Only lost 1 or 2 plants out of 5 flats? Think that was due to critter damage. Otherwise, no signs of cold damage.


Marigolds - Strawberry Blonde showed the most damage. They are very slowly coming out of it. Petite Mix, and French Vanilla showed some signs but nothing like SB. Eskimo just slowed a little bit. No noticeable damage.


Sweet Pea - no damage.


Cosmos - no notable damage. Just slowed way down.


Zinnias - Surprisingly no damage. Just slowed down. Maybe lost 1-2 plants to unknown causes.


Thats all off the top of my head. Other stuff like Cucumbers and Various Squashes never got exposed to the extremes in March, so they are growing just fine.

[BigVanVader]

It is plenty sunny here to use a passive solar design. I would likely add a heated/circulating system for backup (like AKMarks wood stove/water system) though to warm the water when/if needed. Another positive is that they regulate heat very well so useful here even in the dead of summer. A reg greenhouse would be useless here in the summer temps, Id have to open the ends to keep it cool enough.

50 flats is a lot for me to do by myself b/c I work full-time + 3 kids. I like to have a balanced workload so I still enjoy growing and have a little free time. Plus many times people get into the more money for more stuff hamster wheel and never get off. I do want to do this full time at some point, but I think growing slowly as my customer base does w/o ever going in debt for anything is the way I'm comfortable doing it. Otherwise I feel like I'm being self-centered about my hobby. This Spring has been a wild fun ride though! Hoping all these freaking flowers sell by Mothers Day!

[FourOaks]

As long as you have a backup plan, then go for it.


I think the next 2 tunnels that I plan to build will have plastic that either rolls all the way up to the top, or sections that are entirely removable.


The heat is a killer, thats for sure.

[Cole_Robbie]

My plan for tonight, since it is going to rain and snow, and I need to cover my heater, is to put the topper shell off my truck over it, supported by a block under each corner so that enough air can get to the heater. I feel like redneck MacGuyver.

[FourOaks]

Originally Posted by Cole_Robbie

My plan for tonight, since it is going to rain and snow, and I need to cover my heater, is to put the topper shell off my truck over it, supported by a block under each corner so that enough air can get to the heater. I feel like redneck MacGuyver.

What? No Duck Tape?

[Cole_Robbie]

Apparently, I should have run the heater all night constantly and not used the timer. Almost everything has freeze-damage now, especially my tomato plants. I will be culling and giving away a lot of plants next week. They will all live just fine, but no one will buy them with burnt-off edges. The plant selling season has been a complete bust so far. I'm not even sure when I will be back at market.

I'm also coming to despise that diesel heater, especially the smell. Just being in the greenhouse after it has run makes my clothes and hair stink. The smell seems to follow me around. I may have to experiment with kerosene to see if it stinks less.

[FourOaks]

Is propane out of the question?


Im trying to hash together a plan for this winter into next spring. I have a Wood Burner, but hate the idea of constant feeding. I have plenty of accesible firewood.. that helps to ease some pain.


Or maybe, something like a pellet burner? They have an auger, and burn plenty clean.