Hmmmmmmm... I am trying to picture this 'box'. Which side is its long dimension? Vases? More details, please. IMO you should not need thermal transfer material between the heat mat and box. However, is it possible to put the mat 'inside' the box? How adequately sized is this box to deal with properly ventilating the inhabitants? Fans? Vents? The problem for most Vanda isn't temps, its light, and to a lesser extent, humidity. Light, especially where you live is best provided artificially. A low night temp as found in an unheated room is actually a great thing to have as the majority of indoor plants suffer from not great enough a day/night differential. In other words, the box might not be neccessary but (IMO) a couple of light fixtures will be.

H

Hello H. Thank you for your reply. There is a picture of the first two vandas I have in vases posted on 24th May. I have since bought three more and also put them in vases. The blue one is having another spike so I'm guessing they are happy. They will still 'live' in the same bedroom which is centrally heated and gets a lot of light even in winter,perhaps more than in summer due to the sun being lower and penetrating the room more. It will be impractical for me to have extra lighting but I was concerned that the vandas may get too cold should the heating be turned off as we don't have it on constantly.It was only for use on cold nights.
The box would house the five vases which would stick up above the top of it (It's approx.3ft long, 18ins wide and 9ins tall) the whole thing could sit on a heat mat which could be switched on as and when needed but if you think it would not be necessary because it is beneficial to have a varience between temperatures then that would be better not to have the box anyway. I haven't set anything up yet to take a picture.Perhaps I'm being too cautious as I keep reading how warm they like to be kept.
Hazel.

hello, Hazel, I will have start thinking about what to do about my vandas in the winter, too. then I found this website -
http://www.ivensorchids.co.uk/vanda.htm

from the web address, looks like he is in the UK.

sue

Hello Sue, Thank you for that link. It is very informative and I don't think I need to worry about the winter temperatures having read his article. He is in the U.K. so he is aware of our temperatures. I hope your vandas are growing well for you.The new spike on mine is growing quite quickly and I keep checking the others but nothing yet. It is raining cats and dogs here again but is supposed to clear later,Jim is going fishing anyway (but I'm not expecting any plants!!!)
Hazel.

Hello, I have tried to picture what I think the set up would be like -though a little untidily in haste. The box isn't quite as long as I thought but the plants would still fit in O.K. if need be. The heat pad would fit inside but then the vases would not be level ,also I would like to spray the plants and I wonder if that would be safe onto an electrical appliance.Maybe it's not a viable proposition anyway. Meanwhile the vandas will be going back on the windowsill for the rest of the summer.
Hazel.
{{gwi:188429}}

If anything British winters are even cloudier and rainier than North American ones and Vandaceous orchids simply do not have a chance in **** in our northern states without artificial light supplementation. You simply don't know it yet because you haven't had your plants long enough to see what happens after the energy that they arrived with from the grower bleeds off through attrition.

A couple of questions: is the 'heat mat' a horticultural (seedling) type or a household one? It makes a difference. Could not the energy that is now planned for running the heat mat be better used as lumens above the plants? Obviously I think so and such a setup need not be any more or less impractical than it needs to be.

H

hello, Hazel, I have one which is in spike also: it is so beautiful!! the one which which is not happy is still not happy despite the amount of light it is getting: shaded high light: 4000+ foot candles as measured by my light meter from sunrise to sunset and watered with KLN, protekt and seaweed. the bottom leaves continue to yellow and drop. i guess it has decided that it wants to go to orchid heaven and no earthly intervention will work unless there is divine intervention from the orchid gods. (sigh!!!)
sue

Hello H. The mat is a metal hoticultural one which is for raising seedlings. The whole thing is for easy movement as the bedroom is used from time to time when visitors come and I can just lift the whole thing easily. I take your point about the energy being used up but I am preparing as much as I can.The challenge could be worth it.It dropped to 5 degrees here outside last night and that's in August so I moved them off the window sill and put them in the box anyway.
Sue,What a shame about your sickly vanda. At least your spikey one will ease the pain!!!
Hazel.