Plan to use a gas (propane) heater in an Alton Amateur Wood greenhouse. I
Understand i must ventilate top and bottom with a minimum (33 square inches)
vent. Plan to do the bottom vent in wood panel at the foot of the door

I think best place for the apex vent is prolly opposite the door replacing
the 2 small top glass triangular panels .

BUT, any ideas how i can vent at the apex and minimise heat loss at the same
time?

rgds Ramon

"Ramon A" wrote in message
...
Plan to use a gas (propane) heater in an Alton Amateur Wood greenhouse. I
Understand i must ventilate top and bottom with a minimum (33 square
inches)
vent. Plan to do the bottom vent in wood panel at the foot of the door

I think best place for the apex vent is prolly opposite the door replacing
the 2 small top glass triangular panels .

BUT, any ideas how i can vent at the apex and minimise heat loss at the
same
time?

There is no such thing as ventilating without heat loss.

Franz

The message
from "Ramon A" contains these words:

Plan to use a gas (propane) heater in an Alton Amateur Wood greenhouse. I
Understand i must ventilate top and bottom with a minimum (33 square inches)
vent. Plan to do the bottom vent in wood panel at the foot of the door

I think best place for the apex vent is prolly opposite the door replacing
the 2 small top glass triangular panels .

BUT, any ideas how i can vent at the apex and minimise heat loss at the same
time?

rgds Ramon


Better off ventilate than suffocate. The heat loss is not too relevent
IMHO. Unless the vent is huge of course. 8-))

--
email farmer chris on
Please don`t use as it`s a spam haven.

In article , Franz Heymann notfranz.
writes

"Ramon A" wrote in message
...
Plan to use a gas (propane) heater in an Alton Amateur Wood greenhouse. I
Understand i must ventilate top and bottom with a minimum (33 square
inches)
vent. Plan to do the bottom vent in wood panel at the foot of the door

I think best place for the apex vent is prolly opposite the door replacing
the 2 small top glass triangular panels .

BUT, any ideas how i can vent at the apex and minimise heat loss at the
same
time?

There is no such thing as ventilating without heat loss.

But you could get the loss to a very low level by a heat exchange
system. Seems a bit over-elaborate for a greenhouse though ;-)
--
Kay Easton

Edward's earthworm page:
http://www.scarboro.demon.co.uk/edward/index.htm

"Kay Easton" wrote in message
...
In article , Franz Heymann notfranz.
writes

"Ramon A" wrote in message
...
Plan to use a gas (propane) heater in an Alton Amateur Wood greenhouse.
I
Understand i must ventilate top and bottom with a minimum (33 square
inches)
vent. Plan to do the bottom vent in wood panel at the foot of the door

I think best place for the apex vent is prolly opposite the door
replacing
the 2 small top glass triangular panels .

BUT, any ideas how i can vent at the apex and minimise heat loss at the
same
time?

There is no such thing as ventilating without heat loss.

But you could get the loss to a very low level by a heat exchange
system. Seems a bit over-elaborate for a greenhouse though ;-)

True enough, but I have never seen a greenhouse application of that
principle. I did once design such a system for minimising the heat gain in
a
liquid hydrogen container.

Franz

Remember that burning gas gives you Co2 which helps to give you more leaf
and better flower on plants when present in Daytime,
If your glass overlaps sheet by sheet then you will have a certain amount of
air movement through the joints, and I have yet to see a glasshouse that is
air tight.
If you are thinking of fitting Automatic vents the Argos does a good one and
it's the best price I know, but only in the Summer catalogue. (I have one
still working after 9 years, most last 5 to 6 yrs).
If you are looking for a gas heater then you might try
http://www.cmsgardens.co.uk/heaters.htm

Got my last heater from them, good price and good service

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

"........ But you could get the loss to a very low level by a heat exchange
system. Seems a bit over-elaborate for a greenhouse though ;-)

True enough, but I have never seen a greenhouse application of that
principle. .........."

Frank.........try towards the end of the Electric heaters on the site I
posted
http://www.cmsgardens.co.uk/heaters.htm

They do one.
--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk

"........ But you could get the loss to a very low level by a heat exchange
system. Seems a bit over-elaborate for a greenhouse though ;-)

True enough, but I have never seen a greenhouse application of that
principle. .........."

Frank.........try towards the end of the Electric heaters on the site I
posted
http://www.cmsgardens.co.uk/heaters.htm

They do one.
--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk

"David Hill" wrote in message
...
"........ But you could get the loss to a very low level by a heat
exchange
system. Seems a bit over-elaborate for a greenhouse though ;-)

True enough, but I have never seen a greenhouse application of that
principle. .........."

Frank.........try towards the end of the Electric heaters on the site I
posted
http://www.cmsgardens.co.uk/heaters.htm

They do one.

I must be blind. I saw no reference to a heat-exchanging vent in that URL.
By the way, surely electric heaters do not need a vent in the same way as a
paraffin heater needs one?

Franz

"Christopher Norton" wrote in message
...
The message
from "Ramon A" contains these words:



Better off ventilate than suffocate. The heat loss is not too relevent
IMHO. Unless the vent is huge of course.
8-))////////////////////////////you might suffocate if you have the heater
on 24 hours per day and you sleep in the greenhouse........I am still alive
and never vented when using my propane heater......and, as David Hill said,
carbon dioxide is a benefit. Large commercial greenhouses owners spend big
money on a carbon dioxide generating system.

Harold W.

--
email farmer chris on
Please don`t use as it`s a spam haven.

Harold, This was my original thread - Thanks for the input. May I explore
your comment further. Are you saying that for the general use of a gas
heater to keep frost at bay in wintertime, and with a thermostatic control
on the heater then Venting for safety reasons should not be a worry -
assuming that i do not stay in the green house with the heater on and the
door shut - of course???

regards Ramon



8-))////////////////////////////you might suffocate if you have the heater
on 24 hours per day and you sleep in the greenhouse........I am still
alive
and never vented when using my propane heater......and, as David Hill
said,
carbon dioxide is a benefit. Large commercial greenhouses owners spend
big
money on a carbon dioxide generating system.

Harold W.

"....Are you saying that for the general use of a gas
heater to keep frost at bay in wintertime, and with a thermostatic control
on the heater then Venting for safety reasons should not be a worry -
assuming that I do not stay in the green house with the heater on and the
door shut - of course??? ........"

As long as the heater is burning with a Blue flame then you are OK, if the
flame turns yellow then a lack of Oxygen and it will give off Carbon
Monoxide.
If you are really worried then leave the door open half an inch when you are
in there.(But as you let the outside air in you'll also be letting the heat
out).
It's not as if the heater will be running on full flame much of the time
A small metal air vent (What are they 4inches by 8inches?) will be
sufficient and will still keep mice out.




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

"Ramon A" wrote in message
...
Harold, This was my original thread - Thanks for the input. May I explore
your comment further. Are you saying that for the general use of a gas
heater to keep frost at bay in wintertime, and with a thermostatic control
on the heater then Venting for safety reasons should not be a worry -
assuming that i do not stay in the green house with the heater on and the
door shut - of course???
Ramon:

Here is my experience over the years dating back to the 1940's. First using
a parrafin heater and then a propane heater. In the winter the parrafin
heater was on 24 hours per day and the same with the propane heater.(the
propane heater being thermo controlled). I stayed in the greenhouse long
enough to do all the work I needed and basically the only "venting" that I
used was the opening and closing of the door when entering and leaving plus
any "leaks" there might have been.......whatever "leaks" there might have
been were only minor. Sometimes the work in the greenhouse was a couple of
hours or so.........all I can say is that I am alive and a very healthy 78
year older....I am using the past tense as I relocated a couple of years ago
and am now sans a greenhouse......Harold W.........

Ramon



8-))////////////////////////////you might suffocate if you have the
heater
on 24 hours per day and you sleep in the greenhouse........I am still
alive
and never vented when using my propane heater......and, as David Hill
said,
carbon dioxide is a benefit. Large commercial greenhouses owners spend
big
money on a carbon dioxide generating system.

Harold W.

In message , Ramon A
writes
Harold, This was my original thread - Thanks for the input. May I explore
your comment further. Are you saying that for the general use of a gas
heater to keep frost at bay in wintertime, and with a thermostatic control
on the heater then Venting for safety reasons should not be a worry -
assuming that i do not stay in the green house with the heater on and the
door shut - of course???

That depends. Without adequate ventilation and a gas or paraffin burner
you will get a gradual increase of CO2 and when things start getting
critical CO, carbon monoxide building up to dangerous levels. The CO
will potentially kill you stealthily without you noticing. Usually
greenhouses are draughty enough that this isn't such a major risk.
Houses are another matter - there are still far too many fatalities from
dodgy gas burners.

Some plants are also rather intolerant of CO. If you are intent on
taking the risk at least fit a CO alarm so that you don't end up walking
into a trap. I would not even consider using gas or paraffin heaters
without adequate ventilation. Even with ventilation condensation is
always a problem.

Thermostatically controlled electric fan heating is probably cheaper in
a small greenhouse anyway.

Regards,
Martin Brown

regards Ramon



8-))////////////////////////////you might suffocate if you have the heater
on 24 hours per day and you sleep in the greenhouse........I am still
alive
and never vented when using my propane heater......and, as David Hill
said,
carbon dioxide is a benefit. Large commercial greenhouses owners spend
big
money on a carbon dioxide generating system.

Harold W.




--
Martin Brown

Thankyou all for your inputs. I'm grateful to have the benefit of your
collective experience and for taking the time to assist me.
When the job is up and running i'll get back to the ng with some feedback. -
assuming that i aint got gassed in the meantime.
best regards Ramon
"Martin Brown" wrote in message
...
In message , Ramon A
writes
Harold, This was my original thread - Thanks for the input. May I explore
your comment further. Are you saying that for the general use of a gas
heater to keep frost at bay in wintertime, and with a thermostatic
control
on the heater then Venting for safety reasons should not be a worry -
assuming that i do not stay in the green house with the heater on and the
door shut - of course???

That depends. Without adequate ventilation and a gas or paraffin burner
you will get a gradual increase of CO2 and when things start getting
critical CO, carbon monoxide building up to dangerous levels. The CO
will potentially kill you stealthily without you noticing. Usually
greenhouses are draughty enough that this isn't such a major risk.
Houses are another matter - there are still far too many fatalities from
dodgy gas burners.

Some plants are also rather intolerant of CO. If you are intent on
taking the risk at least fit a CO alarm so that you don't end up walking
into a trap. I would not even consider using gas or paraffin heaters
without adequate ventilation. Even with ventilation condensation is
always a problem.

Thermostatically controlled electric fan heating is probably cheaper in
a small greenhouse anyway.

Regards,
Martin Brown

regards Ramon



8-))////////////////////////////you might suffocate if you have the
heater
on 24 hours per day and you sleep in the greenhouse........I am still
alive
and never vented when using my propane heater......and, as David Hill
said,
carbon dioxide is a benefit. Large commercial greenhouses owners spend
big
money on a carbon dioxide generating system.

Harold W.




--
Martin Brown