Greenhouse/Polytunnel insulation

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cartel

Re: Preparation for winter starts in September

Post by cartel »

musa_monkey wrote:Need to think about bubble wrapping the greenhouse soon as well, probably next week. Anyone else made a start ?
I have just bubble wrapped my 12' x 8' greenhouse over the weekend, it took hours!

My dilemma is what do you do about the windows? If I leave them covered then there will be no ventilation and mould will set in, if I cut the bubble wrap to get access for opening the windows then the heating I plan to install will be wasted with cold air coming in from around the windows.

I plan to get a couple of 2Kw electric heaters to get a good airflow, and try to keep the greenhouse at 5c min.

Any thoughts on the ventilation problem?

I also have window shading over the top of the greenhouse. Would I need this with the bubble wrap in place as the light levels in there will be quite low?


Terry
dave2166

Re: Preparation for winter starts in September

Post by dave2166 »

cartel wrote:
musa_monkey wrote:Need to think about bubble wrapping the greenhouse soon as well, probably next week. Anyone else made a start ?
I have just bubble wrapped my 12' x 8' greenhouse over the weekend, it took hours!

My dilemma is what do you do about the windows? If I leave them covered then there will be no ventilation and mould will set in, if I cut the bubble wrap to get access for opening the windows then the heating I plan to install will be wasted with cold air coming in from around the windows.

I plan to get a couple of 2Kw electric heaters to get a good airflow, and try to keep the greenhouse at 5c min.

Any thoughts on the ventilation problem?

I also have window shading over the top of the greenhouse. Would I need this with the bubble wrap in place as the light levels in there will be quite low?


Terry
having almost built my greenhouse this issue has concerned me too.

i think that the lack of ventilation will be more of a concern as damp will do as much damage as cold. however with the heaters too at least you are keeping the air moving and it will be dry air so that will help too.

the vents may still need to open so could you cut around them and put separate piece over the to allow opening??
musa_monkey

Re: Greenhouse/Polytunnel insulation

Post by musa_monkey »

I use a seperate piece of bubble wrap over the louvre vent and the door and i just peg these back during the day to allow air flow through the greenhouse when the weather is warmer. Simple and effective.
musa_monkey

Re: Greenhouse/Polytunnel insulation

Post by musa_monkey »

Terry, i would loose the shading the bubble wrap will reduce light levels enough as it is. Electric heaters should help to keep condensation levels down which in turn should help avoid rot which was a big issue for me last year with paraffin heating.
This year i will switch to electric fan heating when necessary to ensure some air circulation. I know some people even use dehumidifiers but i havent gone that far myself yet.
cartel

Re: Greenhouse/Polytunnel insulation

Post by cartel »

I've just ordered a Bio Green Phoenix 2.8Kw Electric Greenhouse Heater, it looks a serious piece of kit, cost an arm and a leg though. The reviews I've found say this one has a very precise thermostat and an above average fan.

I'm wondering if I can keep the green house at about 10c min would I be able to keep plants like my Ensete maurelii, collocasia, cannas etc. alive in pots through the winter or would this be too expensive to heat to that temperature for the whole winter.


Terry
dave2166

Re: Greenhouse/Polytunnel insulation

Post by dave2166 »

cartel wrote:I've just ordered a Bio Green Phoenix 2.8Kw Electric Greenhouse Heater, it looks a serious piece of kit, cost an arm and a leg though. The reviews I've found say this one has a very precise thermostat and an above average fan.

I'm wondering if I can keep the green house at about 10c min would I be able to keep plants like my Ensete maurelii, collocasia, cannas etc. alive in pots through the winter or would this be too expensive to heat to that temperature for the whole winter.


Terry
let us know how you get on with the heater, as i was thinking about one myself, i think the stats are the best on the market and have a narrower operating range so only work when needed... don't want me lecky bills going thru the roof....LOL

agree with comments about the shading though, get this off and just use the bubble, winter sun, when we get it, is so weak, you need the light and what little warmth it has to get in.
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Dave Brown
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Re: Greenhouse/Polytunnel insulation

Post by Dave Brown »

Terry,

I don't think there is much point in keeping a greenhouse at 10C unless there are plants that require that as a minimum. The main problem with trying to keep things growing is the lack of light, so unless you are going to have additional lighting you are best letting most things go dormant.

Colocasia will just sit there but not grow unless the temp fall below about 3C then the plant collaspes and just goes back to a rhizome.

Ensete ventricosum and cultivars originate in highlands of Ethiopia. around 9 degrees North of the Equator. Their midwinter sun is the same as 18th May here :roll: Any winter growth will be so leggy it will have to be cut off anyway, :roll:
Best regards
Dave
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Libby

Re: Greenhouse/Polytunnel insulation

Post by Libby »

During the summer I use automatic openers. In the winter I remove all but one. The louvered windows (at bottom)are covered inside and out. The one top opening window with automatic opener has just bubblewrap on the glass. This allows for some air circulation plus the opener, opens the green house on those days when, it gets quite hot and you have forgotten to open up!
cartel

Re: Greenhouse/Polytunnel insulation

Post by cartel »

I have a couple of automatic openers which I had removed but I think I'll put one back and add a double layer of bubble wrap to the glass pane, thanks for the tip Libby.

This is going to be an interesting winter as it will be my first with exotics to look after and my first attempt at heating the green house. I'm not sure how I monitor the cost of heating though.

Dave
Do you think it would be OK if I leave the Ensette in it's pot and cut the leaves off or do you think it would fare best removing it and cutting off the roots and leaves as Will Giles does with his.


Terry
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simon
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Re: Greenhouse/Polytunnel insulation

Post by simon »

cartel wrote:I'm not sure how I monitor the cost of heating though.
Hi Terry, Your new heater consumes 2.8kW of electricity. If you look on your electricity bill, a unit of consumption is a kWh (kilowatt hour). This means that the heater willuse 2.8 units for every hour it is on. Because it will be running on a thermostat it is difficult to know exactly how much time it is on for but obviously will run for longer the colder it gets.

You can buy cheap plug-in consumption monitors like these to keep tabs on it. If it looks like it's getting too expensive you can turn it down a degree of two.
Libby

Re: Greenhouse/Polytunnel insulation

Post by Libby »

I may get one of those myself! Thanks!!

By the way I also use those green plastic thingys to attach bubble wrap to greenhouse but I use the long ones so there is a gap between the bubblewrap and the glass, that way I don't get condensation!!
cartel

Re: Greenhouse/Polytunnel insulation

Post by cartel »

simon wrote:
cartel wrote:You can buy cheap plug-in consumption monitors like these to keep tabs on it. If it looks like it's getting too expensive you can turn it down a degree of two.
That looks interesting but I can't help thinking how many Kwh I could get for £11.99, which is the cost of the device and probably get depressed on a daily basis watching the £££ burn away!


Terry
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Dave Brown
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Re: Greenhouse/Polytunnel insulation

Post by Dave Brown »

cartel wrote: That looks interesting but I can't help thinking how many Kwh I could get for £11.99, which is the cost of the device and probably get depressed on a daily basis watching the £££ burn away!


Terry
Terry there is not many Kw/h to the pound now. 10 at most, so saving 120kw/h will recover the cost. I bought one last year and we found over 200w of plug in chargers etc. The appliances were all fully charged but the transformers were using power :roll: 200w is 2.4Kw/h per day, or 216Kw/h per quarter. At 10p per unit that is £21.60 per Bill. Ok you will not recover all of that as the devices will need charging from time to time.

The benefit is it teaches you what is burning your money needlessly. Also as many are wireless you can see how often your heater is switching on. Also id you have a wireless thermometer next to it you can see what temp it is switching on. :wink:
Best regards
Dave
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