Tent In A Shed Insulation?

[MidgeSmith]

Hi, this may well be a stupid question, but it isn't so stupid that the answer is obvious to me

 

I've a 304cm x 244cm x 200cm (max) pent shed in which I am putting a 120cm x 60cm x 180cm grow tent with a 320W Dimmable LED. The whole ceiling and the walls nearest the grow tent are insulated with 50mm Celotex. The remaining walls will be insulated either with Celotex or another insulator.

I plan to use a 6" extractor on a temperature based controller which will vent into the garden in summer and into the shed during winter to preserve warmth. I'm planning to put a couple of thermostatically controlled Tube heaters in the grow room, under a stand with the pots on to keep the growing medium and grow room warm enough when it is cold outside.  I feel like the insulated shed holding the tent would hold heat or even warm up given the exhaust air from the tent too.

 

Do people insulate the outside of their growtent too somehow, or should that be unnecessary?

 

TIA, Midge

[OneMorePuff]

I grow in a tent in my shed too. 

 

A couple of sheets of celotex on the floor underneath the grow tent probably wouldn't go amiss, but I don't think you need to insulate the whole grow tent, no.  The light will actually keep the temps up nicely, and you can vent into the room shed to keep temps up too.  I find venting into the room also increases RH a fair amount, which is good for veg and early flower but not good for late flower.  

 

If the temperature based controller works by just switching the fan on/off when it reaches a certain temp, then I'd reconsider it.  If it just speeds/slows it down then that's fine.  You don't ever want the extraction off.  I use a 6 inch RVK 'L' series fan with a speed controller, and I rarely turn it up above 70%.  I wouldn't really want the extraction controlled by heat to be honest, if I could have it respond to anything, it'd be RH.

 

Speaking of humidity... if you're in the UK then you'll probably want a dehumidifier for late flower.  When the tent is full it can be a real struggle to keep the RH down in this climate, especially on the warm muggy days.  I wouldn't go smaller than 8L.  Put it in the shed outside the tent and turn the extraction down to the lowest possible while still getting negative pressure in the tent.  This will allow the shed to fill with dehumidified air before it gets sucked into the tent and extracted out the window.  The dehumidifier will also add a lot of heat, so you might not need the tube heaters (which I also wouldn't put it in the actual tent).  Treat the room the tent is in, because the air inside the actual tent gets replaced 19 times a minute (I made that figure up, but you get the idea).

[badbillybob]

i also grow in a shed, but  i vent outside, its much easier. 

my shed sits beside a wall, i made a circular hole with a jigsaw at low level and the duct just pokes out, but cant be seen.

i dont haver any temp or humidity issues with this set up. 

 

[blackpoolbouncer]

If you try an vent back into the shed in winter without a means of humid air leaving the shed your gonna have dripping walls and ceilings.

[growinggold]

[Firstimegrower_420]

@growinggoldthats absolutely mental! Love everything about it. 

 

How do people run the electricity from a house into a shed. Do you use extension cables jangling out of window or is an outside electricity box essential? 

 

I can just see me hanging bright yellow JCB electric extension and getting nabbed

Edited September 12, 2021 by Firstimegrower_420

[growinggold]

6 minutes ago, Firstimegrower_420 said:

@growinggoldthats absolutely mental! Love everything about it. 

 

How do people run the electricity from a house into a shed. Do you use extension cables jangling out of window or is an outside electricity box essential? 

 

I can just see me hanging bright yellow JCB electric extension and getting nabbed

 

You will need to get an armoured cabled laid. I got a mate to do it cost about £250. He also put s little fuse breaker board in the shed of you look you can see it on the top right corner with the grey cable coming in below. Well worth the investment and safety first..

[growinggold]

[Firstimegrower_420]

@growinggoldthanks bud that's really helpful to know. 

 

[MidgeSmith]

Thanks everyone for the replies! I am very, very grateful for the time and effort people have put into the words and pictures offered as advice!

@OneMorePuff, thanks for all the information!

I figured I'd go by temperature using a continuous speed modifying controller and run my dehumidifier outside the tent.  It isn't 8 litre, I think it is about 4L, last year it managed to keep my other shed (non growing) to 50% even when it was 85-90% RH - which amazed me. Maybe it would just about cope when it is dealing with humidified air coming from the tent as well as leaching in through the shed walls?  If not, I guess - as you say - I will have to control it by humidity.

I guess I can do some more research into controllers that work by humidity (and or temperature preferably). I was thinking an RVK fan would probably be the best. I was surprised to hear you say the dehumidifier would add to the heat.  As the air that comes out of ours in cooler than the air around it, I imagined it'd cause a heat drop rather than gain, but I guess I haven't had it in a well sealed room and gauged the net effect of the unit heating up, even if it makes cooler air.

Thanks also for the advice re: tube heaters. I saw a wonderful shed grow - on here I think - where the grower had the tube heaters under the pots in the grow chamber and I thought that it might cost less to heat that way, being a smaller space, as it would radiate heat enough to keep the root soil / medium warm as well as convecting air into the chamber. I get your point about the air being replaced in the tent multiple times per hour, but figured maybe after a while there'd be almost equilibrium and still a better heating effect in the shed.

I am happy to try it with the heating tubes in the shed outside the tent, but was concerned they'd be insufficient power then and that I will need to use a germination mat or two as well as the heaters if I do it that way? As I was imagining a net cooling effect from the dehumidifier (which it sounds like an incorrect assumption) I thought I might be causing an antagonistic relationship between the heaters and dehumidifier being in the same place.  As that assumption now sounds wrong - which is great, free heating - perhaps I should have a small oil heater outside of the tent - if anything - and the dehumidifier outside of the tent and vent into the shed during the cold months.

 

@badbillybob I wish I had a wall behind my shed so that I could just vent behind the shed onto the wall! However, my shed IS the 'wall' between my neighbours garden and mine.  In summer I will vent through the side facing my garden, the side on which my tent will be.  I just have to keep it quiet to avoid irritating nosiness from friends and family.  I was thinking of fitting a remote control deadswitch for the circulating fan and extractor so that I can turn them off when people come into the garden and go past the shed and on again once they are clear.

@blackpoolbouncer yeah, I have a dehumidifier that I believe will just about cope.  It should cover me for up to a day at a time. I only need to grow two indoor crops (and one outdoor) a year to stay well medicated.  So if I pick my time right, I should be able to just about get by venting outside for one grow and inside with the dehumidifier running for the other. It doesn't have a continuous out-line, but I can drill a small hole in the collector and fit a tube to take the runoff through the hole the armoured power cable comes up.  That is just under the blind end of the shed.

@growinggold I don't suppose you'd like to adopt me?  I love your work there!  That's what I was imagining for the insulated chamber. Unfortunately, I have to be stealthy as hell, so I can't look as organised as that.  I can't have anything obvious at a glance sitting around in the shed.

It won't matter so much in Winter as nobody will be coming into the garden, but during Summer when friends, neighbours and family are often all over the place, I'll need to throw a tarp over the tent and lean some OSB against the beam above it, to keep it hidden from stolen glances through the windows, or if they demand a peek in and I accidentally left a key in the lock! I haven't figured out what I'll say if anyone asks what is behind the tarp.  I am bound to leave the blinds up at some point though, so I need to get an answer sorted

Could I ask what temp / humidity monitoring kit / app you have as that remote monitoring would be very handy - IF I could get wifi pickup in the shed or it connects via bluetooth!!

@Firstimegrower_420 yeah, as growinggold said, I have an armoured cable.  Though, I laid mine on the surface, behind the neighbours picket fence on my side.  It's at the back of a large border, so nobody is going to dig there while I am living there.

---

There's a lot of food for thought here.  Thanks for busting some of my assumptions and decreasing the chances of me making so many costly mistakes.  I will do some more research in the right fan and controller to keep my tent's environment good and stealth levels high as well as a small heater to try to keep temps up.

Thanks again everyone who has chipped in so far

[growinggold]

No worries mate it's sensor push also does vpd v good hit kit. If I was you I'd be getting a new fan with built in controller from. @Ledgrowlights-Adam and @ledgrowlights-Craig they have some cracking new ones that are auto. I kinda wish I had controller like that for my 6'rvk. I run mine on a basic expelair wac1 which has 5 manual speeds I just leave it on one or two. Mainly one...

 

My shed is also quite overlooked tbh. That why is like it all boxed in..hope just looks like a normal cupboard, rather than tent or insulation. 

[MidgeSmith]

1 hour ago, growinggold said:

No worries mate it's sensor push also does vpd v good hit kit. If I was you I'd be getting a new fan with built in controller from. @Ledgrowlights-Adam and @ledgrowlights-Craig they have some cracking new ones that are auto. I kinda wish I had controller like that for my 6'rvk. I run mine on a basic expelair wac1 which has 5 manual speeds I just leave it on one or two. Mainly one...

 

My shed is also quite overlooked tbh. That why is like it all boxed in..hope just looks like a normal cupboard, rather than tent or insulation. 

That's great, cheers.  I'd forgotten about the Ledgrowlights guys, I will check out what they've got, thanks for the recommendation.

 

Thanks for the deets!

Midge

[Jack?]

A heat Matt would help , with a thermostat. Keeps your roots nice and warm. 

Im in a garage in a kingspan box. extraction going outside having ights running 24/7 with a heat mat should hopefully keep things consistent.

[MidgeSmith]

2 hours ago, Jack? said:

A heat Matt would help , with a thermostat. Keeps your roots nice and warm. 

Im in a garage in a kingspan box. extraction going outside having ights running 24/7 with a heat mat should hopefully keep things consistent.

Thanks for that

 

Can I ask you three questions @Jack? (or anyone else who may be interested in chipping in...)

1) When you put your pots on a heat-mat, do you put them on top of the saucer / tray and put that directly onto it - (as I have in the past) or on a trivet / stand above?

2) Where do you put the temperature sensor?
3) What temperature do you have it set to?
 

[Jack?]

7 hours ago, MidgeSmith said:

Thanks for that

 

Can I ask you three questions @Jack? (or anyone else who may be interested in chipping in...)

1) When you put your pots on a heat-mat, do you put them on top of the saucer / tray and put that directly onto it - (as I have in the past) or on a trivet / stand above?

2) Where do you put the temperature sensor?
3) What temperature do you have it set to?
 

Yeh stick them on your saucers 

Sensors goes in your pots (just stick it in the compost )

Around 21/22 c is good