UK gardening - greenouse heaters, soil warming cables, etc

Author

greenouse heaters, soil warming cables, etc

nospam@nospam.org

2005-12-29, 11:21 am

Hello,

What do you all use to heat your greenhouses?

Are soil cables best since they take the heat to where it is required,
rather than fan heaters which heat the air, most of which does not
come in contact with the plants and quickly escapes?

I have a 3kw greenhouse fan heater but when we had the frost last time
I was unhappy with its frost setting. The problem is that the heater
switches on and the heater body warms-up so the thermostat switches
the heater off. The problem is only the fan heater is now above
freezing; the rest of the greenhouse is not!

I think you need to turn the heater onto the highest setting so that
it is always on and use a separate thermostat to switch it on and off.
I have seen some of these but I don't think they were intended for
outdoor use.

June Hughes

2005-12-29, 11:21 am

In message <qcp7r1pj15149kbiteo26637m17shuvk37@4ax.com>,
nospam@nospam.org writes
>Hello,
>
>What do you all use to heat your greenhouses?
>
>Are soil cables best since they take the heat to where it is required,
>rather than fan heaters which heat the air, most of which does not
>come in contact with the plants and quickly escapes?
>
>I have a 3kw greenhouse fan heater but when we had the frost last time
>I was unhappy with its frost setting. The problem is that the heater
>switches on and the heater body warms-up so the thermostat switches
>the heater off. The problem is only the fan heater is now above
>freezing; the rest of the greenhouse is not!
>
>I think you need to turn the heater onto the highest setting so that
>it is always on and use a separate thermostat to switch it on and off.
>I have seen some of these but I don't think they were intended for
>outdoor use.
I like a little paraffin stove but think that is probably old fashioned
these days. However, the smell is lovely and takes me back to my
childhood. Haven't used it for a couple of years.
--
June Hughes

Hugh Jampton

2005-12-29, 11:21 am

On Thu, 29 Dec 2005 14:45:03 GMT, nospam@nospam.org wrote:

> I have a 3kw greenhouse fan heater but when we had the frost last time
> I was unhappy with its frost setting. The problem is that the heater
> switches on and the heater body warms-up so the thermostat switches
> the heater off. The problem is only the fan heater is now above
> freezing; the rest of the greenhouse is not!

I have a Parasene electric greenhouse fan heater. When I bought my first
one it acted like you say. I exchanged it but the second one acted in the
same way. I exchanged it again and the third one worked fine and is still
in use. Temperature here last night dropped to - 6° C and the heater kept
the lowest temperature in the greenhouse to + 5° C set on the next setting
to frost protection - it does not run continuously.
--
Regards,

Hugh Jampton

kenty;\)

2005-12-29, 2:21 pm

<nospam@nospam.org> wrote in message
news:qcp7r1pj15149kbiteo26637m17shuvk37@4ax.com...
> Hello,
>
> What do you all use to heat your greenhouses?
>
> Are soil cables best since they take the heat to where it is required,
> rather than fan heaters which heat the air, most of which does not
> come in contact with the plants and quickly escapes?
>
> I have a 3kw greenhouse fan heater but when we had the frost last time
> I was unhappy with its frost setting. The problem is that the heater
> switches on and the heater body warms-up so the thermostat switches
> the heater off. The problem is only the fan heater is now above
> freezing; the rest of the greenhouse is not!
>
> I think you need to turn the heater onto the highest setting so that
> it is always on and use a separate thermostat to switch it on and off.
> I have seen some of these but I don't think they were intended for
> outdoor use.

Depends what size greenhouse you want to heat,how full is it,what is in
it/minimum temp you want to keep,if not alot could you section it to save
costs.If only a few small plants then possibly a soil warming cable /stat
with a frame above enclosing with bubble insulation .
I have a 10x8 greenhouse for growing orchids,i keep a min temp of 58f with a
3 kw electric fan heater on full controlled by a independant
thermostat/sensor.I also have two fans running 24/7.
So what you intend to grow is the factor in what setup is needed.Also good
insulation of the greenhouse is key in keeping the costs down.Don't even
consider using a heater without this.
Cheers Keith
PS don't be shy ,give a name.

Chris Hogg

2005-12-29, 4:21 pm

On Thu, 29 Dec 2005 15:02:11 +0000, Hugh Jampton <me@privacy.net>
wrote:

>On Thu, 29 Dec 2005 14:45:03 GMT, nospam@nospam.org wrote:
>
>
>I have a Parasene electric greenhouse fan heater. When I bought my first
>one it acted like you say. I exchanged it but the second one acted in the
>same way. I exchanged it again and the third one worked fine and is still
>in use. Temperature here last night dropped to - 6° C and the heater kept
>the lowest temperature in the greenhouse to + 5° C set on the next setting
>to frost protection - it does not run continuously.

I also have one of these. The thermostat isn't a true thermostat IMO,
but seems to work like a combination of a thermostat and an energy
regulator. A little of the warm air from the heater is diverted across
the thermostat, which then cuts out before the body of the greenhouse
gets up to temperature. But then in cold air the thermostat cools
quickly and comes back on again. The colder the air, the quicker this
happens. As the air temperature warms up, it takes longer for the
thermostat to come back on again. I suppose it's meant to be a clever
system, raising the g/h temperature gently without running the risk of
overshooting or cooking anything, but give me a straightforward
thermostat that holds a constant temperature, anytime.

--
Chris

E-mail: christopher[dot]hogg[at]virgin[dot]net

LinkBot