Is anyone familiar with the Marley 240v Electric Heater for a greenhouse?
Any comments on this model? Can you recommend a different heater if you
feel this not adequate?
http://www.littlegreenhouse.com/acce...heaters2.shtml

I am currently putting up an 8 1/2" x 12" glass greenhouse and this model is
the one that I found on the internet that I believe will be the best value
to do the job. I am in central North Carolina, zone 7b, and we do get winter
temps in the teens a few times during the cold spells.

Thank you,
Bobby
--
Bobby Baxter
TheGardenSite.com
Your Web Site Is Waiting For You

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TheGardenSite.com: http://thegardensite.com
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Gardens Of The World: http://thegardensite.com/gardens
Iris Gardens Of The World: http://thegardensite.com/irises
Daylily.Net: http://daylily.net
GardenTalk Forum: http://thegardensite.com/gardentalk/

I had a 220V supplemental heater in a 14 x 14 GH when I lived in coastal SC.
I also had about a dozen 55-gallon black steel drums full of water as
passive solar heat storage, so could afford the electricity. I would
recommend against electricity otherwise, and push for a propane heater.

Doing a bit of a "back of the envelope" calculation, if we assume
floor-to-ceiling glass, 6-foot tall walls, and a peaked roof, you've got
something in the vicinity of 384 square feet of glass to lose heat through.
Assuming an outdoor minimum of 10°F, and interior 55°, you'll need about a
20,000 BTU gas heater, or about a 6000W electric heater.

The Marley would probably do fine, but assuming it would need to run for
12-18 hours a day, you're talking 67 to -100 KWH/day clocking on that
electric meter!

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

.. . . . . . . . . . .
"Bobby Baxter" wrote in message
. com...
Is anyone familiar with the Marley 240v Electric Heater for a greenhouse?
Any comments on this model? Can you recommend a different heater if you
feel this not adequate?
http://www.littlegreenhouse.com/acce...heaters2.shtml

I am currently putting up an 8 1/2" x 12" glass greenhouse and this model
is
the one that I found on the internet that I believe will be the best value
to do the job. I am in central North Carolina, zone 7b, and we do get
winter
temps in the teens a few times during the cold spells.

Thank you,
Bobby
--
Bobby Baxter
TheGardenSite.com
Your Web Site Is Waiting For You

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TheGardenSite.com: http://thegardensite.com
Daylily Gardens Of The World: http://daylily.net/gardens
Gardens Of The World: http://thegardensite.com/gardens
Iris Gardens Of The World: http://thegardensite.com/irises
Daylily.Net: http://daylily.net
GardenTalk Forum: http://thegardensite.com/gardentalk/

I did the same sort of back of the envelope thing last night and got about
the same numbers as Ray. When the heater is running you will be using the
juice that would be required to light 100 60W light bulbs. If your house
has the normal 200 amp service, this unit will require over 10% of that
service when ever it is on. Depending on the area, electric heat can be 3
to 4 times more expensive to run then gas, oil or propane. The extra cost
of installing one of these non electric heaters will often be paid for in
less than one heating season. I know lots of people that are very happy
with natural gas, but for many of us that is not an option. I prefer oil to
propane because of the ethylene produced by burning propane (oil is also a
little cheaper per BTU). If you opt for propane, make sure the unit is
power vented.
Pat

Pat Brennan wrote:

I did the same sort of back of the envelope thing last night and got about
the same numbers as Ray. When the heater is running you will be using the
juice that would be required to light 100 60W light bulbs. If your house
has the normal 200 amp service, this unit will require over 10% of that
service when ever it is on. Depending on the area, electric heat can be 3
to 4 times more expensive to run then gas, oil or propane. The extra cost
of installing one of these non electric heaters will often be paid for in
less than one heating season. I know lots of people that are very happy
with natural gas, but for many of us that is not an option. I prefer oil to
propane because of the ethylene produced by burning propane (oil is also a
little cheaper per BTU). If you opt for propane, make sure the unit is
power vented.
Pat


Pat,

And if your house was built more than 15 years or so ago, you
probably have 100A service (or 60A, in my old 1940's house). I'd hate
to see what that load would do on 60A - you would minimally expect your
home electronics to burp every time the greenhouse heater kicks in - I
bet it would destroy my TIVO. Figure a couple thousand dollars to
upgrade to 200A (after the power company charges you for the new wires,
and the electrician charges you for the installation, pay permits from
the city, and you decide to go ahead and bury the wires since you are
mucking with it anyway, and.... anyway, I've been there already.
Twice).

Do you have a source for oil fired greenhouse heaters? I've only
seen propane or gas, but I haven't looked hard. Since I already heat
the house with oil, it makes sense to heat the greenhouse the same way.
I'd need another oil tank, but that isn't too expensive. For what it is
worth, my furnace guy says that warm oil burns better than cold, so if
you have the option you should put the tank in a heated space. I don't
think I'll be putting a fuel oil tank in my greenhouse, but I thought
I'd throw that out there.

Does anybody use an oil fired boiler for hot water heat in the
greenhouse? I'm thinking hot water heat is the way to go for me. You
can probably make a serious dent in your fuel bill by putting a solar
hot water collector in line with your oil boiler. It is cheaper to heat
hot water, and even on a cloudy day the solar water would be at least
somewhat warm... Actually if you put a solar hot water collector in
line with one of those 'on demand' electric water heaters, you might be
able to heat a greenhouse with electricity for an almost reasonable
price. You can build a solar water system from spare parts and your
neighbors garbage. Or at least my neighbor's garbage (I see an old hot
water tank out there right now).

Rob

--
Rob's Rules: http://www.msu.edu/~halgren
1) There is always room for one more orchid
2) There is always room for two more orchids
2a. See rule 1
3) When one has insufficient credit to purchase
more orchids, obtain more credit

10ºF where the heck are you growing orchids?

i worrry about it getting below 50ºf for more than a couple of days

Jim
"Ray" wrote in message
...
I had a 220V supplemental heater in a 14 x 14 GH when I lived in coastal
SC.
I also had about a dozen 55-gallon black steel drums full of water as
passive solar heat storage, so could afford the electricity. I would
recommend against electricity otherwise, and push for a propane heater.

Doing a bit of a "back of the envelope" calculation, if we assume
floor-to-ceiling glass, 6-foot tall walls, and a peaked roof, you've got
something in the vicinity of 384 square feet of glass to lose heat
through.
Assuming an outdoor minimum of 10°F, and interior 55°, you'll need about a
20,000 BTU gas heater, or about a 6000W electric heater.

The Marley would probably do fine, but assuming it would need to run for
12-18 hours a day, you're talking 67 to -100 KWH/day clocking on that
electric meter!

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

. . . . . . . . . . .
"Bobby Baxter" wrote in message
. com...
Is anyone familiar with the Marley 240v Electric Heater for a
greenhouse?
Any comments on this model? Can you recommend a different heater if you
feel this not adequate?
http://www.littlegreenhouse.com/acce...heaters2.shtml

I am currently putting up an 8 1/2" x 12" glass greenhouse and this
model
is
the one that I found on the internet that I believe will be the best
value
to do the job. I am in central North Carolina, zone 7b, and we do get
winter
temps in the teens a few times during the cold spells.

Thank you,
Bobby
--
Bobby Baxter
TheGardenSite.com
Your Web Site Is Waiting For You

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TheGardenSite.com: http://thegardensite.com
Daylily Gardens Of The World: http://daylily.net/gardens
Gardens Of The World: http://thegardensite.com/gardens
Iris Gardens Of The World: http://thegardensite.com/irises
Daylily.Net: http://daylily.net
GardenTalk Forum: http://thegardensite.com/gardentalk/

"Rob Halgren" wrote in message
...
[snip]
I'd need another oil tank, but that isn't too expensive. For what it is
worth, my furnace guy says that warm oil burns better than cold, so if
you have the option you should put the tank in a heated space. I don't

This makes perfect sense. After all, combustion is just a redox reaction,
and like all chemical reactions has an activation energy. It follows, then,
that the colder the fuel is the more energy is wasted adding energy to it to
get it to reach the activation energy required for the reaction to occur.
Your net energy gain from your redox reaction will thus be greater the
warmer your fuel is.

Cheers,

Ted

Hell, that's nuthin'.

I've got customers in Alaska!

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

.. . . . . . . . . . .
"Jim S" wrote in message
. com...
10ºF where the heck are you growing orchids?

i worrry about it getting below 50ºf for more than a couple of days

Jim
"Ray" wrote in message
...
I had a 220V supplemental heater in a 14 x 14 GH when I lived in coastal
SC.
I also had about a dozen 55-gallon black steel drums full of water as
passive solar heat storage, so could afford the electricity. I would
recommend against electricity otherwise, and push for a propane heater.

Doing a bit of a "back of the envelope" calculation, if we assume
floor-to-ceiling glass, 6-foot tall walls, and a peaked roof, you've got
something in the vicinity of 384 square feet of glass to lose heat
through.
Assuming an outdoor minimum of 10°F, and interior 55°, you'll need about
a
20,000 BTU gas heater, or about a 6000W electric heater.

The Marley would probably do fine, but assuming it would need to run for
12-18 hours a day, you're talking 67 to -100 KWH/day clocking on that
electric meter!

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

. . . . . . . . . . .
"Bobby Baxter" wrote in message
. com...
Is anyone familiar with the Marley 240v Electric Heater for a
greenhouse?
Any comments on this model? Can you recommend a different heater if
you
feel this not adequate?
http://www.littlegreenhouse.com/acce...heaters2.shtml

I am currently putting up an 8 1/2" x 12" glass greenhouse and this
model
is
the one that I found on the internet that I believe will be the best
value
to do the job. I am in central North Carolina, zone 7b, and we do get
winter
temps in the teens a few times during the cold spells.

Thank you,
Bobby
--
Bobby Baxter
TheGardenSite.com
Your Web Site Is Waiting For You

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TheGardenSite.com: http://thegardensite.com
Daylily Gardens Of The World: http://daylily.net/gardens
Gardens Of The World: http://thegardensite.com/gardens
Iris Gardens Of The World: http://thegardensite.com/irises
Daylily.Net: http://daylily.net
GardenTalk Forum: http://thegardensite.com/gardentalk/

Rob,

Oil starts jelling at around -20. When temps start getting into the -teens
I start adding an anti jelling agent to the oil. Tanks in a heated area
would get rid of this headache and cost. At a minimum, the tank should be
plumbed with dual lines as the return line helps warm the oil in the tank.
If your greenhouse is big enough and you do a little fast talking, I bet
your oil supply company to be will have a real deal for the tank. Tank size
is an issue here, if they are too big they come under EPA regs. Smaller
tanks are your friend and the more frequent fillups are not your headache.

My main source for heat is oil hot air. Sunderman makes a fine unit in two
sizes. It is basically a Beckett burner, heat exchange and blower covered
with sheet metal. They looks cheap but have proven to be workhorses that
locals can work on. I do not think there is anything special about a
greenhouse heater except for size. For smaller greenhouses I expect a house
unit would work just fine. In fact I use a house boiler for under bench
heating in my seedling area.

If your pockets are deep, two smaller units are much safer than a single
unit. If you only have one main heater some sort of backup heat is a must.
When it is zero outside and the heater fails you just do not have much time,
and if you can get a repairman out at 3 am on a snowy night, he will not
have the right parts on the truck.

Talking about boilers, they can bite you. To operate a boiler in a
commercial setting I must have it state inspected every year and carry a
special insurance (that would be boiler insurance). It is worth doing some
checking before going the boiler route. I know a guy who heated his
greenhouse with a hot water heater and a circulating pump. The hot water
heater was nothing more than a low cost boiler.

I was in a greenhouse the other day that was heated using radiant heat. I
do not know much about it, but I really liked the feel of the heat. It
seemed to heat the plants on the benches and not all the air in the
greenhouse. It has to be cheaper operate. Might be worth looking into.

Pat

Rob,

Oil starts jelling at around -20. When temps start getting into the -teens
I start adding an anti jelling agent to the oil. Tanks in a heated area
would get rid of this headache and cost. At a minimum, the tank should be
plumbed with dual lines as the return line helps warm the oil in the tank.
If your greenhouse is big enough and you do a little fast talking, I bet
your oil supply company to be will have a real deal for the tank. Tank size
is an issue here, if they are too big they come under EPA regs. Smaller
tanks are your friend and the more frequent fillups are not your headache.

My main source for heat is oil hot air. Sunderman makes a fine unit in two
sizes. It is basically a Beckett burner, heat exchange and blower covered
with sheet metal. They looks cheap but have proven to be workhorses that
locals can work on. I do not think there is anything special about a
greenhouse heater except for size. For smaller greenhouses I expect a house
unit would work just fine. In fact I use a house boiler for under bench
heating in my seedling area.

If your pockets are deep, two smaller units are much safer than a single
unit. If you only have one main heater some sort of backup heat is a must.
When it is zero outside and the heater fails you just do not have much time,
and if you can get a repairman out at 3 am on a snowy night, he will not
have the right parts on the truck.

Talking about boilers, they can bite you. To operate a boiler in a
commercial setting I must have it state inspected every year and carry a
special insurance (that would be boiler insurance). It is worth doing some
checking before going the boiler route. I know a guy who heated his
greenhouse with a hot water heater and a circulating pump. The hot water
heater was nothing more than a low cost boiler.

I was in a greenhouse the other day that was heated using radiant heat. I
do not know much about it, but I really liked the feel of the heat. It
seemed to heat the plants on the benches and not all the air in the
greenhouse. It has to be cheaper operate. Might be worth looking into.

Pat

I am enjoying the input from this forum. Our fireplace is gas and I have
120 gallon tank for it. However, we really do not want to place another
tank in the yard. As our garden develops it will most likely be unreachable
by the truck that fills the tank if we had one back by the greenhouse. I am
ready to suck up some extra expense on the electric bill, especially since
it will be used for my business. I am not currently growing orchids but
knew this would be the appropriate forum for this discussion. I will be
using the green house for hybridizing daylilies and seed production. I will
also be doing some conversions from diploid to tetraploid and using BAP for
rapid propogation of plants to produce offshutes.

It looks like I should have some type of propane heater for backup when the
power is lost. We have had some rough ice storms in the winter. Probably
need a tank like for a gas grill. Any recommendations for this type of
backup heater?

Thanks again,
Bobby

--
Bobby Baxter
TheGardenSite.com
Your Web Site Is Waiting For You

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TheGardenSite.com: http://thegardensite.com
Daylily Gardens Of The World: http://daylily.net/gardens
Gardens Of The World: http://thegardensite.com/gardens
Iris Gardens Of The World: http://thegardensite.com/irises
Daylily.Net: http://daylily.net
GardenTalk Forum: http://thegardensite.com/gardentalk/

Don't let the distance to the greenhouse from the tank play a role in your
thought process. My GH heater uses propane, and the tank and heater are
about 150 feet apart. All it takes is some buried copper tubing!

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

.. . . . . . . . . . .
"Bobby Baxter" wrote in message
. com...
I am enjoying the input from this forum. Our fireplace is gas and I have
120 gallon tank for it. However, we really do not want to place another
tank in the yard. As our garden develops it will most likely be
unreachable
by the truck that fills the tank if we had one back by the greenhouse. I
am
ready to suck up some extra expense on the electric bill, especially since
it will be used for my business. I am not currently growing orchids but
knew this would be the appropriate forum for this discussion. I will be
using the green house for hybridizing daylilies and seed production. I
will
also be doing some conversions from diploid to tetraploid and using BAP
for
rapid propogation of plants to produce offshutes.

It looks like I should have some type of propane heater for backup when
the
power is lost. We have had some rough ice storms in the winter. Probably
need a tank like for a gas grill. Any recommendations for this type of
backup heater?

Thanks again,
Bobby

--
Bobby Baxter
TheGardenSite.com
Your Web Site Is Waiting For You

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TheGardenSite.com: http://thegardensite.com
Daylily Gardens Of The World: http://daylily.net/gardens
Gardens Of The World: http://thegardensite.com/gardens
Iris Gardens Of The World: http://thegardensite.com/irises
Daylily.Net: http://daylily.net
GardenTalk Forum: http://thegardensite.com/gardentalk/

Ray, I will need to check with the gas guys to see if there is any problem
running another line from the tank to the greenhouse. I think my wife will
be much more comfortable with electric, but I will check into the propane
options.

Thanks,
Bobby


--
Bobby Baxter
TheGardenSite.com
Your Web Site Is Waiting For You

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TheGardenSite.com: http://thegardensite.com
Daylily Gardens Of The World: http://daylily.net/gardens
Gardens Of The World: http://thegardensite.com/gardens
Iris Gardens Of The World: http://thegardensite.com/irises
Daylily.Net: http://daylily.net
GardenTalk Forum: http://thegardensite.com/gardentalk/





"Ray" wrote in message
...
Don't let the distance to the greenhouse from the tank play a role in your
thought process. My GH heater uses propane, and the tank and heater are
about 150 feet apart. All it takes is some buried copper tubing!

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

Bobby,

Whatever you do, you're sure to feel better simply knowing that you don't
have to worry about the plants freezing on those cold nights!

One last caveat: electric heat in a wet greenhouse can be dangerous. Be
sure to 1) ground it well, and 2) shield it in a way that prevents
accidental watering or even misting. When I used one, it was inside a
"tunnel" with stacked and siliconed brick walls on the sides, and a piece of
galvanized "roofing tin" siliconed to the top, with the front and back open
for the constant air flow of the GH fans.


--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!

.. . . . . . . . . . .
"Bobby Baxter" wrote in message
. com...
Ray, I will need to check with the gas guys to see if there is any problem
running another line from the tank to the greenhouse. I think my wife
will
be much more comfortable with electric, but I will check into the propane
options.

Thanks,
Bobby


--
Bobby Baxter
TheGardenSite.com
Your Web Site Is Waiting For You

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TheGardenSite.com: http://thegardensite.com
Daylily Gardens Of The World: http://daylily.net/gardens
Gardens Of The World: http://thegardensite.com/gardens
Iris Gardens Of The World: http://thegardensite.com/irises
Daylily.Net: http://daylily.net
GardenTalk Forum: http://thegardensite.com/gardentalk/





"Ray" wrote in message
...
Don't let the distance to the greenhouse from the tank play a role in
your
thought process. My GH heater uses propane, and the tank and heater are
about 150 feet apart. All it takes is some buried copper tubing!

--

Ray Barkalow - First Rays Orchids - www.firstrays.com
Plants, Supplies, Books, Artwork, and Lots of Free Info!