Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old 04-08-2004, 12:23 PM
Amber Ormerod
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse

Would using soil heating cables be an economic way of keeping plants frost
free in the winter? I am presuming that the heat will rise and keep the rest
of the plant warm. I would expect that not as much heat will be lost via the
top of the greenhouse because it will at least have a chance to heat up
something and some will get stored. Or is soil warming strictly for
propagation? Or does everyone just use heaters?
I know this sounds early to be asking but my cacti buying feet are itching
and so I need to sort out winter residences before buying too many to be
able to use windowl edges.

thanks
amber



  #2   Report Post  
Old 04-08-2004, 02:47 PM
pronoun
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse

Hi Amber,

You may consider building a bubble wrap dome inside the greenhouse. I used
this to good effect last winter in a large DIY propagator with heating
cables controlled by a lighting dimmer switch. If this is feasable, try to
arrange the roof, such that the condensation drips back into the soil (sand
in my case.) This is by far the most economic method I know.


"Amber Ormerod" wrote in message
...
Would using soil heating cables be an economic way of keeping plants frost
free in the winter? I am presuming that the heat will rise and keep the

rest
===============cut==========


  #3   Report Post  
Old 04-08-2004, 09:08 PM
Chris R. Lee
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse

Hope you used a special transformer. A dimmer gives pulses of mains voltage
that are a lethal as the straight mains.

Regards


"pronoun" a écrit dans le message de news:
...
Hi Amber,

You may consider building a bubble wrap dome inside the greenhouse. I

used
this to good effect last winter in a large DIY propagator with heating
cables controlled by a lighting dimmer switch. If this is feasable, try

to
arrange the roof, such that the condensation drips back into the soil

(sand
in my case.) This is by far the most economic method I know.


"Amber Ormerod" wrote in message
...
Would using soil heating cables be an economic way of keeping plants

frost
free in the winter? I am presuming that the heat will rise and keep the

rest
===============cut==========




  #4   Report Post  
Old 04-08-2004, 11:20 PM
Chris French and Helen Johnson
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse

In message , Chris R. Lee
writes
Hope you used a special transformer. A dimmer gives pulses of mains voltage
that are a lethal as the straight mains.

And why is this a problem?

AFAIK heating cables are mains voltage anyway - I have one in home made
propagator controlled by a rod thermostat control no transformer AFAIK
--
Chris French and Helen Johnson, Leeds
urg Suppliers and References FAQ:
http://www.familyfrench.co.uk/garden/urgfaq/index.html
  #5   Report Post  
Old 04-08-2004, 11:44 PM
Amber Ormerod
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse


"pronoun" wrote in message
...
Hi Amber,

You may consider building a bubble wrap dome inside the greenhouse. I

used
this to good effect last winter in a large DIY propagator with heating
cables controlled by a lighting dimmer switch. If this is feasable, try

to
arrange the roof, such that the condensation drips back into the soil

(sand
in my case.) This is by far the most economic method I know.


so the heated cables method won't end up with the bottom warm and the top
too cold?




  #6   Report Post  
Old 05-08-2004, 07:07 AM
Franz Heymann
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse


"pronoun" wrote in message
...
Hi Amber,

You may consider building a bubble wrap dome inside the greenhouse.

I used
this to good effect last winter in a large DIY propagator with

heating
cables controlled by a lighting dimmer switch.


Unless I misunderstand you, you have a deadly system in mind, unless
you are using a transformer and low voltage cables.

[snip]

Franz


  #7   Report Post  
Old 05-08-2004, 07:07 AM
Franz Heymann
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse


"Chris French and Helen Johnson"
wrote in message ...
In message , Chris R. Lee
writes
Hope you used a special transformer. A dimmer gives pulses of mains

voltage
that are a lethal as the straight mains.

And why is this a problem?

AFAIK heating cables are mains voltage anyway - I have one in home

made
propagator controlled by a rod thermostat control no transformer

AFAIK

Blimey

Franz


  #8   Report Post  
Old 05-08-2004, 02:08 PM
pronoun
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse

Hi Franz,

I'm still here--and it still works ok. You just need to make sure the
wattage rating of the dimmer exceeds that of the soil heating cable, and
also that the soil / sand stays damp to conduct the heat and avoid hotspots.
My cable is designed for this use at mains voltage. I admit the use of a
dimmer was my own idea--to save the cost of a thermostat. It would be best
to use a thermostat designed for the job. I think my cable was 40 feet
long. I fixed it to plastic fencing with nylon cable ties so that it kept a
snake like shape, and to prevent the coils touching when buried in the sand.
I would be more nervous of an electric blanket in bed. I may have a photo
somewhere--if your interested.

"Franz Heymann" wrote in message
...

"pronoun" wrote in message
...
Hi Amber,

You may consider building a bubble wrap dome inside the greenhouse.

I used
this to good effect last winter in a large DIY propagator with

heating
cables controlled by a lighting dimmer switch.


Unless I misunderstand you, you have a deadly system in mind, unless
you are using a transformer and low voltage cables.

[snip]

Franz




  #9   Report Post  
Old 05-08-2004, 09:16 PM
David Hill
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse

I think the idea of using a dimmer instead of a thermostat is false economy.
What you should be aiming for is a soil temp. of around 46-50f, with that
you can get away with an air temp of around 40f, or even down to 36f with
some plants.
You would be better using a time switch, but a thermostat is best as with a
hard frost you will want that extra time with the cable running on full to
maintain the temp.
At least with a timer you could give extra heat during the night, esp. from
around midnight to about 7am.
I wouldn't worry about a bublewrap tent, a single layer of polythene to form
a tent away from the glass will serve just as well, and if you have a fan
heater in there to keep the air frost free then you should do well.
Last winter I used a polythene tent inside a 24ftx 40ft tunnel. the tent was
7 ft in the centre and down to 5 ft at the sides. This cut the area being
heated down by around half, and meant I could get away with less powerful
heaters, and a lot less electric.
As spring came on I raised the tent till it was only reducing the air space
by about 15%.
One advantage of this was a great reduction in condensation as there was no
Cold film against the Warm air.
As the sun warmed the house I didn't have an insulated film (as you would
have with bubble wrap) keeping the heat away from the plants.

--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk




  #10   Report Post  
Old 06-08-2004, 08:09 AM
Chris French and Helen Johnson
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse

In message , Franz Heymann
writes

"Chris French and Helen Johnson"
wrote in message ...
In message , Chris R. Lee
writes
Hope you used a special transformer. A dimmer gives pulses of mains

voltage
that are a lethal as the straight mains.

And why is this a problem?

AFAIK heating cables are mains voltage anyway - I have one in home

made
propagator controlled by a rod thermostat control no transformer

AFAIK

Blimey


What's the problem here Franz? Soil warming cables, thermostats etc. all
standard kit intended for greenhouses - as is my mains electric heater,
and
--
Chris French and Helen Johnson, Leeds
urg Suppliers and References FAQ:
http://www.familyfrench.co.uk/garden/urgfaq/index.html


  #11   Report Post  
Old 06-08-2004, 08:51 PM
Franz Heymann
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse


"Chris French and Helen Johnson"
wrote in message ...
In message , Franz Heymann
writes

"Chris French and Helen Johnson"


wrote in message ...
In message , Chris R.

Lee
writes
Hope you used a special transformer. A dimmer gives pulses of

mains
voltage
that are a lethal as the straight mains.

And why is this a problem?

AFAIK heating cables are mains voltage anyway - I have one in

home
made
propagator controlled by a rod thermostat control no transformer

AFAIK

Blimey


What's the problem here Franz? Soil warming cables, thermostats etc.

all
standard kit intended for greenhouses - as is my mains electric

heater,

I would not go near mains heating cables buried in damp earth. Full
stop.
Low voltage units are available for this obvious reason.

Franz


  #12   Report Post  
Old 07-08-2004, 12:24 AM
Chris French and Helen Johnson
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse

In message , Franz Heymann
writes

"Chris French and Helen Johnson"
wrote in message ...


What's the problem here Franz? Soil warming cables, thermostats etc.

all
standard kit intended for greenhouses - as is my mains electric

heater,

I would not go near mains heating cables buried in damp earth. Full
stop.


Fair enough, but AFAIAC they are safe. Obviously I would not put it in a
situation were I would be likely to damage it, - but otherwise I don't
see a problem. mine sits in the wooden propagator box in damp sand the
cable is insulated and sealed. If it was to develop a fault in the
insulation then it would just trip the RCD anyway.

Low voltage units are available for this obvious reason.


I guess they are, though I can't actually think
of ever seeing them on sale.
--
Chris French and Helen Johnson, Leeds
urg Suppliers and References FAQ:
http://www.familyfrench.co.uk/garden/urgfaq/index.html
  #13   Report Post  
Old 07-08-2004, 07:06 AM
Franz Heymann
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse


"Chris French and Helen Johnson"
wrote in message ...
In message , Franz Heymann
writes

"Chris French and Helen Johnson"


wrote in message ...


What's the problem here Franz? Soil warming cables, thermostats

etc.
all
standard kit intended for greenhouses - as is my mains electric

heater,

I would not go near mains heating cables buried in damp earth.

Full
stop.


Fair enough, but AFAIAC they are safe. Obviously I would not put it

in a
situation were I would be likely to damage it, - but otherwise I

don't
see a problem. mine sits in the wooden propagator box in damp sand

the
cable is insulated and sealed. If it was to develop a fault in the
insulation then it would just trip the RCD anyway.


Only if the propagator itself is connected to earth.

Low voltage units are available for this obvious reason.


I guess they are, though I can't actually think
of ever seeing them on sale.


I used to have one when I still had a greenhouse. It ran at 12 volts
and used bare soft iron wires as the heating elements.

Franz


  #14   Report Post  
Old 07-08-2004, 03:49 PM
Chris French and Helen Johnson
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse

In message , Franz Heymann
writes

"Chris French and Helen Johnson"
wrote in message ...
but otherwise I

don't
see a problem. mine sits in the wooden propagator box in damp sand

the
cable is insulated and sealed. If it was to develop a fault in the
insulation then it would just trip the RCD anyway.


Only if the propagator itself is connected to earth.


And how would I earth a wooden propagator? :-)

The cable itself is earthed of course.

(though if you have mains electricity in a GH then yes I guess any metal
work such as staging etc. should be earth bonded
--
Chris French and Helen Johnson, Leeds
urg Suppliers and References FAQ:
http://www.familyfrench.co.uk/garden/urgfaq/index.html
  #15   Report Post  
Old 08-08-2004, 06:36 AM
Franz Heymann
 
Posts: n/a
Default soil heating cables for winter use/heating a greenhouse


"Chris French and Helen Johnson"
wrote in message ...
In message , Franz Heymann
writes

"Chris French and Helen Johnson"


wrote in message ...
but otherwise I

don't
see a problem. mine sits in the wooden propagator box in damp

sand
the
cable is insulated and sealed. If it was to develop a fault in

the
insulation then it would just trip the RCD anyway.


Only if the propagator itself is connected to earth.


And how would I earth a wooden propagator? :-)


Stick a metal peg into the damp soil and connect the peg to another
one driven into damp soil in the "real earth".

The cable itself is earthed of course.


That would not help you in this case, unless I misunderstand what you
mean by "the cable itself is earthed".

(though if you have mains electricity in a GH then yes I guess any

metal
work such as staging etc. should be earth bonded.


It would be good practice to do so.

Franz




Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is Off
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
parasene soil cables thehams United Kingdom 0 07-09-2006 06:23 PM
greenouse heaters, soil warming cables, etc Hugh Jampton United Kingdom 1 29-12-2005 07:53 PM
greenouse heaters, soil warming cables, etc kenty;\) United Kingdom 0 29-12-2005 06:12 PM
Working with soil warming cables Michael Savage United Kingdom 3 01-12-2003 08:14 PM
Do I need substrate heating cables? [email protected] Freshwater Aquaria Plants 12 07-10-2003 01:40 AM


All times are GMT +1. The time now is 05:12 PM.

Powered by vBulletin® Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Copyright ©2004-2019 GardenBanter.co.uk.
The comments are property of their posters.
 

About Us

"It's about Gardening"

 

Copyright © 2017