heating

[ehanes7612]

converted from using two standard 1500 watt electric heaters to 9k/12k/15k propane tank top heater...works great for my space of 15 x 12 greenhouse, providing a 60 degree temp inside (using low setting of 9k) when outside temps are in the 30's. Of course, the only problem is a thermostat,if temps go lower i have to manually adjust to 12k/15k.. luckily temps in seattle are pretty consistent during the winter early spring...but i will eventually need a propane heater with automatic thermostat..hopefully this wont cost more than the electric heaters...testing it now...seeing how much 9k burns up in continuous use (can only find specs on continuous use of 15k....dont know if efficiency stays the same)...i will probably go back to just using one electric heater (no propane) at the end of march, when our lows average back in the forties

 

[Ozpaph]

Just curious, but even if the outside temp fell 10-20 degrees the inside would stay above freezing even at the 9K setting?

 

[ehanes7612]

Just curious, but even if the outside temp fell 10-20 degrees the inside would stay above freezing even at the 9K setting?

yeaaaah..
i would think so...but i need to keep temps near 60 ...so if the outside temps got that low i would have to adjust to higher setting

 

[Rick]

My GH is similar sized (12 X12) But it does get colder in TN than for you Seattle typesoke:.


I bought one of those "blue flame" ventless indoor propane heaters. I think mine is actually rated at 30,000BTU. I got it from Home Depot.

It has a thermocouple based thermostat in it (so requires no electricity, but still regulated by temperature). I think there is a smaller/cheaper one than the 30,000 BTU unit. They have electric fans built in, but using them is optional, and the burners will still light and maintain proper heating during power outages.

A quick google search shows a 20,000 BTU unit at $150

I've experienced the 3 set level type heater that you described, and would get out of it if you can afford the blue flame type for 2 reasons.

1) thermostatic control without the use of electricity (saving $$ on propane)
2) The ventless indoor types never produce enough propane exhaust fumes to bud blast your plants (which may happen with less efficient models).

 

[ehanes7612]

yeah..i think just from running this overnight it consumes way too much propane to make this more affordable than our electricity...ugh

 

[ehanes7612]

My GH is similar sized (12 X12) But it does get colder in TN than for you Seattle typesoke:.


I bought one of those "blue flame" ventless indoor propane heaters. I think mine is actually rated at 30,000BTU. I got it from Home Depot.

It has a thermocouple based thermostat in it (so requires no electricity, but still regulated by temperature). I think there is a smaller/cheaper one than the 30,000 BTU unit. They have electric fans built in, but using them is optional, and the burners will still light and maintain proper heating during power outages.

A quick google search shows a 20,000 BTU unit at $150

I've experienced the 3 set level type heater that you described, and would get out of it if you can afford the blue flame type for 2 reasons.

1) thermostatic control without the use of electricity (saving $$ on propane)
2) The ventless indoor types never produce enough propane exhaust fumes to bud blast your plants (which may happen with less efficient models).

but i will look into this...if i do propane, i will need a thermostat

 

[jtrmd]

My GH is similar sized (12 X12) But it does get colder in TN than for you Seattle typesoke:.


I bought one of those "blue flame" ventless indoor propane heaters. I think mine is actually rated at 30,000BTU. I got it from Home Depot.

It has a thermocouple based thermostat in it (so requires no electricity, but still regulated by temperature). I think there is a smaller/cheaper one than the 30,000 BTU unit. They have electric fans built in, but using them is optional, and the burners will still light and maintain proper heating during power outages.

A quick google search shows a 20,000 BTU unit at $150

I've experienced the 3 set level type heater that you described, and would get out of it if you can afford the blue flame type for 2 reasons.

1) thermostatic control without the use of electricity (saving $$ on propane)
2) The ventless indoor types never produce enough propane exhaust fumes to bud blast your plants (which may happen with less efficient models).

Dont mean to hijack the thread,but was wondering how your 'Blue Flame' heater stands up to the humidity and stuff.I have been wanting to switch from electric to natural gas for some time.

 

[ehanes7612]

Dont mean to hijack the thread,but was wondering how your 'Blue Flame' heater stands up to the humidity and stuff.I have been wanting to switch from electric to natural gas for some time.

good question, wondering the same thing

 

[Rick]

Dont mean to hijack the thread,but was wondering how your 'Blue Flame' heater stands up to the humidity and stuff.I have been wanting to switch from electric to natural gas for some time.

The casing is a bit rusty, but I've been using the same unit for at least 5 years now. The most consistent problem has been that the pilot orifice clogs with some type of deposit during the summer when the unit is totally shut down. It would probably save effort and anxiety if I pulled the orifice out at the end of the winter heating season. Clean it, dry it, and store it in a plastic bag or something. But I never do, and when I go to fire it up the first night of pending frost in fall, I always spend hours cursing myself hunkered down on the GH floor trying to get the thing running.

I've mentioned this in some other threads on this topic, but when there is a power outage, the circulation fan (and all the other fans in your GH) will not be running. Yes this unit will fire up and make flames on its own, but heat rises. So the floor of the GH stays cold, and up high it gets really warm. So having some battery backup fans or minimal generator is still a very good idea to circulate the heat from these units.

 

[ehanes7612]

decided not to go with propane...costs twice as much to heat compared to electricity (10 dollars a day vs 5 a day)...4 /gallon for propane is expensive

 

[jtrmd]

Rick

What kind of thermostat ar eyou using,or are you not using one?

 

[ehanes7612]

Rick

What kind of thermostat ar eyou using,or are you not using one?

not using one...the heater was left on the lowest setting and managed to keep the GH at 60 degrees all night (my deisred setting) and it still cost too much

 

[Rick]

Rick

What kind of thermostat ar eyou using,or are you not using one?

The Blueflame ventless heaters have their own built in variable thermostat.

Its actually a thermocouple, which does not require electricity.

It relies on fluid presure feeding back to a regulator valve.

So it has a fluid filled (probably mercury) in a metal bulb at the end of a metal tube. As the fluid cools, it contracts and pulls (or pushes) against a variable tension adjusted diaphragm in the gas control valve.

"temperature adjustment" is based on how much tension you dial into this valve. The more you torque down the tension the higher the temp required to push the valve open and send the gas to the burner (where it is lit by the constant burning pilot light).

 

[jtrmd]

not using one...the heater was left on the lowest setting and managed to keep the GH at 60 degrees all night (my deisred setting) and it still cost too much

What are you growing that wont allow u to go below 60?

 

[ehanes7612]

What are you growing that wont allow u to go below 60?

paph seedlings a year out of flask (which take up more than half my space)...it actually goes down to 57...but working on insulating GH so that i only need to use one basic electric heater (costs 3.5 dollars a day to operate) ,with a backup if needed for night...right now i need a second heater if it falls below 35 outside (this is our average low temp for wintertime)

 

[jtrmd]

what are ur walls.
I am heating a 12 x 14 gh with triple wall polycarb. with a 6mil poly lining on the inside with 1 1500w Dayton utility heater.I can use just that to maintain 55 degrees easily until Jan.I notice it cycles quite a bit,and is never on constantly.When we get down in the 20s at night,or get snow I kick on the other two Delohngi's (set on their lowest settings 900w ?) for back up.They are all connected to outlets that are wired to Dayton thermostats.

 

[ehanes7612]

what are ur walls.
I am heating a 12 x 14 gh with triple wall polycarb. with a 6mil poly lining on the inside with 1 1500w Dayton utility heater.I can use just that to maintain 55 degrees easily until Jan.I notice it cycles quite a bit,and is never on constantly.When we get down in the 20s at night,or get snow I kick on the other two Delohngi's (set on their lowest settings 900w ?) for back up.They are all connected to outlets that are wired to Dayton thermostats.

12 x 15 x ten feet high ..oh i definitely have room for improvement...right now i have double (3 inch gap) layer 6mil plastic with a 3 ml plastic coating wrapped around that...but i have a clear plastic layer sealed at six feet high as a ceiling (helps bring up the temp about 5 degrees)...if i had polycarb...that would probably solve my problem...and i will need it anyway by next summer (for the apple tree bombs above the greenhouse ) as well as replacing the outside layer plastic that has a short lifespan...polycarb is my next purchase for sure...my neighbor has a polycarb greenhouse

 

[tim]

ima just put this out there: youve spent how much on plants? and now you want to skimp on an aspect of growing them that may mean the death of your entire collection? why not just get a normal propane heater? they're on craigslist all the time and if not, a new one for a space your size is like $500...the cost of three or four flasks!

I'm sure that seattle is different than new england, but even when i was in california i still had a normal propane heater in my greenhouse. i can understand the urge to cut corners, but why this particular one?

 

[ehanes7612]

ima just put this out there: youve spent how much on plants? and now you want to skimp on an aspect of growing them that may mean the death of your entire collection? why not just get a normal propane heater? they're on craigslist all the time and if not, a new one for a space your size is like $500...the cost of three or four flasks!

I'm sure that seattle is different than new england, but even when i was in california i still had a normal propane heater in my greenhouse. i can understand the urge to cut corners, but why this particular one?[/QUOT

im not sure how you got that i am skimping or cutting corners..just looking for the best way to heat....propane is twice as expensive as our electric and on top of that i have to refill it every two days..and on top of that its a fossil fuel ...70 percent of our electricity is renewable from dams...so why would i pay twice as much for heating by using a fossil fuel ...the propane was just an experiment...if i lived in New England then i would probably go for propane


I am not worried about losing my plants to weatherour weather is much more predictable here

 

[Rick]

In my case the non electric propane system is the backup/redundancy system not the primary heating system. Propane is expensive in TN. However, it's probably "greener" than electricity in this region, since coal is still king out here.

But from October to April its not improbable to have nights below freezing (its going to be in the mid 20's tonight). And Dec to March could have night temps in the teens and 20's for weeks on end. Lots of crazy weather with lots of trees near power lines makes for lots of power outages in the rural areas.

So I need a non electrical backup. I've been chastised before, but auto backup emergency generators are too $$ for me, even if I've spent 10X that in plants over the last 10 years. However, I do have access to a small manual start portable to run some fans if the juice goes out for an extended period.

I think insulating is still the best bang for the buck. Tanks of water to fill up unused air space and increased thermal storage is also great to eek out more efficiency. I know we've been focusing on walls and roofs, but don't forget the floor. Mine is still dirt/ gravel. I really need to bury some sheets of thick styrofoam.