Page 1 of 2

Fans for ventilation?

Posted: Mon May 13, 2019 8:59 am
by makleodss
Hello fellow cacti growers. As weather is getting warmer again arise an issue with ventilation. All the time I used desktop fans for cooling my consercatory but they just keep burning off after a season. Where to source some proper durable greenhose fans which would provide good air movement and will last at least few years. Cheers!

Re: Fans for ventilation?

Posted: Mon May 13, 2019 9:13 am
by el48tel
Many greenhouse fan heaters have a non-heat setting. You could use the unit in cold mode. The problem with desk fans is the rating factor for the motor is not for continuous use.

Re: Fans for ventilation?

Posted: Mon May 13, 2019 10:31 am
by ChrisR
I use two of these year round in my 20 x10 and leave them on for months at a time. They really keep the air moving!

https://www.screwfix.com/p/18-floor-fan-220-240v/3939x

Re: Fans for ventilation?

Posted: Mon May 13, 2019 10:33 am
by Chez2
We just bought an average, mid range desk top fan. We have ours on in autumn to push the damp air out our polytunnel. We have had similar fans for other purposes for years.

Re: Fans for ventilation?

Posted: Mon May 13, 2019 12:45 pm
by agavedave
Had one of these for 4 years in a 10 x 8 GH

https://www.amazon.co.uk/Honeywell-Powe ... 003KHJO6G/


Dave..

Re: Fans for ventilation?

Posted: Mon May 13, 2019 12:53 pm
by el48tel
Chez2 wrote: Mon May 13, 2019 10:33 am We just bought an average, mid range desk top fan. We have ours on in autumn to push the damp air out our polytunnel. We have had similar fans for other purposes for years.
Sorry ... I should have made myself clearer. Why buy a fan if your heater which has an electrical safety rating for use in damp conditions and a motor rating for 24h continual use? Not all desktop fans are electrical safety rated for use in damp conditions even if protected by the correct switching gear, nor might be 24h rated. Running in cold mode is Ok. And one piece of gear rather than two?

Re: Fans for ventilation?

Posted: Mon May 13, 2019 2:19 pm
by Chez2
el48tel wrote: Mon May 13, 2019 12:53 pm
Chez2 wrote: Mon May 13, 2019 10:33 am We just bought an average, mid range desk top fan. We have ours on in autumn to push the damp air out our polytunnel. We have had similar fans for other purposes for years.
Sorry ... I should have made myself clearer. Why buy a fan if your heater which has an electrical safety rating for use in damp conditions and a motor rating for 24h continual use? Not all desktop fans are electrical safety rated for use in damp conditions even if protected by the correct switching gear, nor might be 24h rated. Running in cold mode is Ok. And one piece of gear rather than two?
......we don't have a fan heater. When we did it was only on when the greenhouse needed heating.

We have a 30 x 18 foot polytunnel with a greenhouse gas heater in the middle. The gas heater is on a thermostat and the fan is turned off at the socket at night. Its plugged in to one of the covered, outdoor waterproof sockets within the tunnel.

Re: Fans for ventilation?

Posted: Mon May 13, 2019 2:42 pm
by el48tel
Chez2 wrote: Mon May 13, 2019 2:19 pm
el48tel wrote: Mon May 13, 2019 12:53 pm
Chez2 wrote: Mon May 13, 2019 10:33 am We just bought an average, mid range desk top fan. We have ours on in autumn to push the damp air out our polytunnel. We have had similar fans for other purposes for years.
Sorry ... I should have made myself clearer. Why buy a fan if your heater which has an electrical safety rating for use in damp conditions and a motor rating for 24h continual use? Not all desktop fans are electrical safety rated for use in damp conditions even if protected by the correct switching gear, nor might be 24h rated. Running in cold mode is Ok. And one piece of gear rather than two?
......we don't have a fan heater. When we did it was only on when the greenhouse needed heating.

We have a 30 x 18 foot polytunnel with a greenhouse gas heater in the middle. The gas heater is on a thermostat and the fan is turned off at the socket at night. Its plugged in to one of the covered, outdoor waterproof sockets within the tunnel.
Not talking about the socket which should be correctly IP rated anyway. Talking about the fan itself which should be correctly IP rated. Domestic fans are not sufficiently constructed to be used in damp or exterior conditions and carry a lower IP grading. The warranty will not be valid because it is being used in conditions outside the ones stipulated in the purchase agreement / sale contract conditions and you could run foul of the HSE for being outside the current IEE regulations. Trust me you don't want a visit from them - they will check every piece of everything, equipment and documentation (I say that because you say you are business premises - and they can be quite unpleasant).

Re: Fans for ventilation?

Posted: Mon May 13, 2019 5:11 pm
by Phil_SK
I like desk fans because they can sweep a good area. I'm mostly bothered by still air around the plants rather than where I can feel it.

Re: Fans for ventilation?

Posted: Mon May 13, 2019 5:48 pm
by Chez2
el48tel wrote: Mon May 13, 2019 2:42 pm
Chez2 wrote: Mon May 13, 2019 2:19 pm
el48tel wrote: Mon May 13, 2019 12:53 pm

Sorry ... I should have made myself clearer. Why buy a fan if your heater which has an electrical safety rating for use in damp conditions and a motor rating for 24h continual use? Not all desktop fans are electrical safety rated for use in damp conditions even if protected by the correct switching gear, nor might be 24h rated. Running in cold mode is Ok. And one piece of gear rather than two?
......we don't have a fan heater. When we did it was only on when the greenhouse needed heating.

We have a 30 x 18 foot polytunnel with a greenhouse gas heater in the middle. The gas heater is on a thermostat and the fan is turned off at the socket at night. Its plugged in to one of the covered, outdoor waterproof sockets within the tunnel.
Not talking about the socket which should be correctly IP rated anyway. Talking about the fan itself which should be correctly IP rated. Domestic fans are not sufficiently constructed to be used in damp or exterior conditions and carry a lower IP grading. The warranty will not be valid because it is being used in conditions outside the ones stipulated in the purchase agreement / sale contract conditions and you could run foul of the HSE for being outside the current IEE regulations. Trust me you don't want a visit from them - they will check every piece of everything, equipment and documentation (I say that because you say you are business premises - and they can be quite unpleasant).
No, we are not a business premises. Polytunnel is ours for our use only. Our last fan is still going strong, had it for years, possibly well over a decade.

Our company is Waste Management (disposal and recycling of mainly hazardous waste) and Waste Legislation consultancy to businesses, nothing to do with horticulture.