Garden Room

Sure this has come up before, but I put a fan in my conservatory last year on a segment timer approx 15-mins on and 30-45 mins off.

last winter was wet, previous winter was very dry (I watered plants OUTSIDE during that winter!)

last winter I had no problems with mould at all. Previous winter I had quite a few problems.

 

I considered this for the Orangery we are building - as a plant room.

My thinking was that heating would only be required on a cold night, and on a rare night that temperature outside is -16C the building must be able to maintain temperature.

Underfloor heating has very slow response time, and creates a heat reservoir in the floor mass - which evens the temperatures out. So I think that you heat the floor (because it is cold) and then the sun comes out and the temperature of the plant room rises, the heating goes off, but the floor carries on pumping out heat :(

So I've gone for radiators (off the central heating) for a faster response. I suppose I may need to also put a 3kW fan heater in there for the -16C nights - although the building is very well insulated, and constructed with dense blocks to improve thermal-mass, so might find it is not needed.

In the conservatory, alongside the Orangery, which is aimed to be part plants and part humans I have installed underfloor heating, but only about 50% of what is needed, and then some small radiators. The idea is that if we decide not to live in it in the winter then the underfloor heating will only provide background, and the radiators will provide emergency heat on cold nights. If we do live in it then the Rads will provide make-up temperature too.

Time will tell how good these decisions turn out to be!

 

Shiney - yes, the condensation comes from the transpiration of all that foliage, and the wet pots represent a huge resevoir of water, that has no way of escape.

Ideally, ventilation is the best way of avoiding condensation. But as I am heating the room to 10C with electricity I can't afford to open windows and let all that heat out. And there have been very few days recently when its been more that 10C outside during the day, other than for short bursts when the sun shines. But as long as I am removing the water manually, I am essentially achieving the same end as ventilation. I have thought about a fan to move the air - but everything seems to be very healthy at the moment.

I would agree with Kristen about underfloor heating. Its great in a house where it removes the need for radiators and frees up wall space, but I think it would be too slow to respond in a garden room.

Kristen - I bought a couple of those German thermostats (thank you for the suggestion) and they seem to be doing a good job. I am measuring the temperature at 8 different places at the moment (boy's toys ). The temperature seems to be rock steady at 10C in the centre of the room, but down to 7.5C right at the front next to the glass.

 

Have you thought about a de-humidifier Peter?

 

I have Sheal. But I suspect that it wouldn't be much use. Though I would like to borrow one to try.

I originally assumed that a dehumidifier was the way to go until I spoke to a consultant to the Tomato Growers Association, who was on an advice desk at the Harrogate Flower Show. He said that it wouldn't be much use. This set me thinking and I did a bit of research on the subject.

The way a dehumidifier works, as I understand it, is that it is essentially a small fridge. It cools some fins down to about 5C and a fan draws air across these cold fins where moisture condenses and drops into a tray. The temperature of the fins can't be much below 5C or the moisture would freeze onto the fins and clog the system up.

I read the small print on the side of a dehumidifier box in my local DIY store. It was rated as up to 160 litres per 24 hours, which looked good. But it said that this rating was at 30C and 80% humidity. It also said that at 5C it wouldn't remove anything, which is logical considering how it works. What this means is that if you heat a greenhouse to just 5C, the dehumidifier fins would be no colder than the glass panes themselves - so 99.9% of the humidity would condense on the walls of the greenhouse and not on the fins. In my case I am heating my room to 10C, so a bit more would condense inside the dehumidifier, but if the fins are only 5C colder than the walls and ceiling it wouldn't be very efficient.

 

At 10°c I suspect that you will want to retain some humidity anyway for bug control?

 

My humidity is currently 100% permanently - so I have a bit to spare. But yes, the spiders mite not like it.

I asked the same consultant, mentioned above, about humidifiers and humidity control for the summer. I am coming round to the feeling that I have to decide what climate I want the Garden Room to have - and hot and humid seems to be a logical choice for the summer. The consultant said that proper climate control would be very expensive and throwing a bucket of water on the floor in summer would be just as good and cheaper that spray misters.

 

I agree! I wet the floor under the benches and the lower panes too in the greenhouse. The pots stand on gravel in trays which is also topped up with water. I've been practically RSM free for the first time in years.

 

Interesting LongK

 

RSM loathes humidity! White fly is none too keen on it either.

 

I have bought a Coolnet Fogger (not sure if it was someone on this forum, or a different one, that recommended it). I've not tried it as yet, but my intention was to see how well it works - compared to chucking a bucket on the floor! I would quite like solutions that are not dependent on me remembering to do it - or to be HERE to do it!

Some doubt about how my water hardness might clog it, over time.


http://www.access-irrigation.co.uk/shop/sprinklers/small-sprinklers/coolnet-fogger

 

One of the reasons that I like to wet the floor is that I don't need to worry about scorching the leaves on sunny days.

 

Its a good point. I don't think "fog" will do that ... but we'll see. I'll have a go next summer - assuming the builders have left by then!!!

 

I tend to agree regarding fogging.
The point that I was trying to make (rather badly!) is that I prefer the wet floor over spraying for humidity!