Original Greenhouse Heating Question

 

Just to clarify the question, here's my original post to the home
improvement group:


We have a small greenhouse attached to the south side of our home.
It's 14' X 12' with a shed roof tapering from 10' on the house side
to
6'. Roughly 1,400 cubic feet. It's a 2x4 frame with double-walled
polycarbonate sheeting, 10mm for the roof and 6mm for the sides.
We're
in Maryland, near Baltimore, so it rarely gets below the mid-teens in
the winter.

We heat it with a 220V electric heater, 5,600 watts and 19,110 BTUh
rating. This generally keeps it at the 50 degrees the plants require
but occasionally my wife puts on a 110V supplimental heater on cold
nights.

The power hasn't failed in the winter since we got the greenhouse but
it's probably only a matter of time. I was thinking of getting a
kerosene heater as back-up to the electrical heaters. Home Depot has
a
23,000 BTU heater for $129 which seems to fit our needs. Could I use
home heating oil for this or would it be better to stick with pure
kerosene?

I was wondering about a propane heater; would that be more efficient
than kerosene? We have a propane ball/tank for some other
applications
which aren't used in the winter.


Paul

 

wrote:


We use a propane non-vented heater in a personnal greenhouse and it
works well in conjuction with automatic roof vents and a circulation
fan.  I'm not sure you need as much heat as this unit puts out, but I
assume they make many sizes.  I suppose the CO2 put out may make a
difference, but have not noticed it.

 

Pavel314 wrote:

If you want to cut down on the heating bill you can add some insulation.
Home Despot has 1/2" polyiso (R3):

http://www.rmaxinc.com/

I use it in my solar stuff, works well outdoors and is non flamable and
relatively green.

   You aren't getting much light from other than your south facing
vertical wall (with the sun so low), so you may wish to have a winter
cover for this. It would add R3 to your R2 walls and roof. Take it down
when you don't need it. Cut the bill in half or so...

   Just an idea.

   Jeff

 


<http://attra.ncat.org/attra-pub/solar-gh.html>


 Lots of stuff.

  Bill

--
Garden in shade zone 5 S Jersey USA

    deals with Sugars

 



Here is a BTU and an Area calculator that may help,   however it sounds like
you have a good primary and a very good supplement/emergency system.
http://www.littlegreenhouse.com/area-calc.shtml
http://www.littlegreenhouse.com/heat-calc.shtml

Try transparent bubble wrap insulation  inside instead of insulation
material and clear packing tape  to secure it.  Comes in 4 ft rolls but  buy
it from a place like here:
http://www.starboxes.com/medium-bubble.aspx?CategoryIDD  and not the UPS or
the FEDEX stores. Much cheaper and free shipping.