Author Topic: Can a home extractor fan vent into a greenhouse?  (Read 2118 times)

OllieC

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Can a home extractor fan vent into a greenhouse?
« on: February 13, 2012, 09:21:01 »
Just curious really. We're thinking of building our own house (okay, having our own house built) & as you'd expect I'm considerably more interested in the gardening than the planning side of things. It's very early stages but one thing I've seen is the heat reclaiming extractor fans - which get around half your heat back into the incoming air. I was wondering whether it might be possible to stick the other half into a greenhouse. Any thoughts on the practicalities?

Linnea

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Re: Can a home extractor fan vent into a greenhouse?
« Reply #1 on: February 13, 2012, 09:35:18 »
I keep looking at the steam coming out of our boiler flue and wondering if I can heat our greehouse with it.
I'm no architect or technician but the concerns I would have are

1. flue is at head height therefore would need to channel down into greenhouse (hot air rising therefore inlet would need to be at the bottom of the greenhouse?) how would this affect cooling of the air? i.e. how much hot air would be left after it's travelled down the pipework

2. heat lost from the greenhouse. we only have the bog-standard single glazed version but I would think you'd need a brick built double glazed to see any effect. (maybe not an issue if you build the greenhouse whilst building the house.

3. would the amount of hot air from the flue actually make any difference - guess this would depend on the size of the greenhouse to be heated

4. location of greenhouse to boiler outlet- therefore distance of pipework/compromising of paths/walkways/access around the house

just some thoughts. as I said I'm not expert so probably worthwhile consulting one. I think it is a possibility

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Linnea

Chrispy

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Re: Can a home extractor fan vent into a greenhouse?
« Reply #2 on: February 13, 2012, 09:49:27 »
Linnea, your plants would love all the carbon dioxide from your boiler flue, unfortanatly you would run the risk gassing yourself if you ever went in the greenhouse so I would not consider it.

Can't see any problem with Ollies idea, but you might find your greenhouse smelling of your cooking.
« Last Edit: February 13, 2012, 09:57:47 by Chrispy »
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petengade

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Re: Can a home extractor fan vent into a greenhouse?
« Reply #3 on: February 13, 2012, 10:41:29 »
Linnea , dont try it, the Carbon Monoxide given off the boiler is a killer as Chrispy says

Linnea

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Re: Can a home extractor fan vent into a greenhouse?
« Reply #4 on: February 13, 2012, 10:48:41 »
According to the gas engineer the "steam" is clean from the flue but the practicalities of my situation means I wouldn't try it anyway but thanks for the concern

goodlife

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Re: Can a home extractor fan vent into a greenhouse?
« Reply #5 on: February 13, 2012, 11:15:25 »
It could well be that 'steam' would turn the environment too damp..then the fungal problems would be your trouble.
Unless you would install heater too and turn it into tropics... ;D ;) Just think of the crops you could grow... ;D

Chrispy

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Re: Can a home extractor fan vent into a greenhouse?
« Reply #6 on: February 13, 2012, 11:17:57 »
According to the gas engineer the "steam" is clean from the flue but the practicalities of my situation means I wouldn't try it anyway but thanks for the concern
It is still full of carbon dioxide, and that will kill you if it too high a concentration.
Carbon monoxide is a lower risk, as a correctly working boiler should not give off any, but if it is old, inefficient or faulty, then the carbon monoxide will kill you as well.
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Chrispy

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Re: Can a home extractor fan vent into a greenhouse?
« Reply #7 on: February 13, 2012, 11:28:31 »
Ollie, I was forgeting the extration point in the bathroom  :-X
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OllieC

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Re: Can a home extractor fan vent into a greenhouse?
« Reply #8 on: February 13, 2012, 11:37:18 »
It does seem a waste to chuck all that heat away, doesn't it. I think with a flue there would be a problem as you're venting into a confined space which as well as trapping the CO2 also could restrict the flow - and almost certainly would be against the manufacturer's instructions. Lots of damp too, as said. You might be able to grow great mushrooms though?

In our case, we're looking at a very well insulated house (I hate the term but it will be an eco house, possibly to a Passivhaus standard) - so you get systems that link in all the extractor fans (kitchen & bathrooms) and extract through a heat exchange. This is what I'd like to investigate sticking into a greenhouse. Maybe it would extend the season by a few weeks or maybe it could increase growth rates, or maybe the heat would just go away in no time. I guess most extraction is in the day, and the coldest time must be around 2 AM so the effect might be minimal?

This is going to be in the Highlands so any extra heat is greatly appreciated!

@Chrispy - yep, so you get the smell of farts too?!

ACE

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Re: Can a home extractor fan vent into a greenhouse?
« Reply #9 on: February 13, 2012, 12:11:41 »
We have a walled courtyard that is 'heated' by the central heating flue and the aga exhaust. So an open air option might suit your ideas.

We grow our most of our tender stuff in there with great success. Just make sure the door is self closing as I found out to our cost once.

 

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