Building a Simple Electrical Heater - Part 2

Recent additions - electrical heater box and growlight panel, both on test

I've put this on a separate post to my original, because the whole design has now become a little more complex !

After building the two identical electrical resistance heating elements, I spotted a 6" (150 mm) 24 VDC fan at our local car boot sale a couple of weeks ago.  This was snapped up for £2.  

the fan....

With this addition, I thought I could maybe improve on my original free-convection idea and wire up this fan in parallel to our two heating elements, to push the air over the heaters.

Growing Palm Trees from Seed ...

My wife has always wanted a palm tree in our garden.  Despite my insistence that this is bloody-freezing Northern England and therefore it's just not possible, I've had to endure the accusing glances and disparaging comments whenever we've driven past other local gardens in which, admittedly, many appear to be flourishing.

Our nearest garden centre also stocks several of them, but they're all under the protection of the glasshouse areas and not standing out in the open ground.  The smallest versions are more than twenty-five quid each and they even want around £300 for some of the larger specimens !

Anyway, we were on holiday in scorching-hot Mallorca in early August, and on one of our many trips out and about on the hired motorbike we passed a Spanish garden centre and stopped for a browse.  

Making a LED Growlight Panel

This is another build for the greenhouse electrics.  Growlights.

I've been reading up a bit about the light requirements of plants.  There's a lot of very technical stuff out there, but basically it seems that blue-ish light is best for seedlings & green vegetative growth and red-ish light for germination, flowering and fruiting.  

One of the many images from a Google search on the subject of plant light
requirements.  Unfortunately, this was one of several in a wide ranging
cut-and-paste job, and so I don't have the link for an acknowledgement....

Since the plan is to supplement the available sunlight in the winter when we start off the leeks and onions etc, then mostly blue seems the order of the day with just a splash of red.

It gets even more technical when they start talking about specific individual wavelengths within the blue and red regions for optimum growth, e.g. 439, 469, 642 & 677 nanometres, but blue is blue and red is red as far as I'm concerned - there must be at least some of the light emitted that touches on these optimum wavelengths.

Building a Simple Electrical Heater

This is following on from my recent post on the greenhouse solar installation.

To use any excess panel energy available during the cooler months, I've built electrical heating elements to connect directly to the 'dump load' circuit from the charge controller.  There are no proprietary heating elements available for the power and voltage I require, and even if there were then they'd likely be prohibitively expensive.

The first job was to source some suitable resistance wire.  Lots of types available on eBay but not too many which are insulated, so I opted for enamelled 0.7 mm diameter Isotan wire (aka Konstantan) available from a seller in Norway.

The reason for buying insulated wire was that it could be formed either in or around metal pipe or ducting.   In the end, I opted for inserting it in small-bore copper tubing, a coil of which I had lying around the workshop.  

However, this wasn't the only choice for the design - I'd originally envisaged simply wrapping the insulated wire around the outside of a 22 mm diameter copper pipe, but I didn't have any to hand and B&Q wanted £17 for a 2 metre length....

I unrolled the small-bore copper tubing coil and measured its length at 7.2 m.   A few basic calculations were carried out to establish the heating power available from the lengths of tube and wire I had.   

Standalone Solar Installation....

We decided it would be good to have some electrical power in the greenhouse, primarily for growlights and at least one of our electric propagators during the winter months.

Taking power via a spur from the house mains is not so easy - there's nowhere to run a cable underground without cutting slots across at least one concrete pathway.  The best alternative solution would be overhead, from the house wall via a cable supported by a catenary wire.

However, the amount of power we're looking to draw is not huge, and so we've simply relocated three of the solar panels from our experimental array onto the greenhouse roof.

Is this how Financial Independence arrives - not with a bang but a whimper ?

My recent post about the company's finances made me think very seriously about the state of our personal finances, and what may be possible in '...retirement...' or at least for long periods without a regular earned income.

Using some of the 'float' we've established in the company, in the last few days I've set up a large monthly contribution from the company into my personal SIPP.   Making contributions to an employee's pension plan is also an allowable expense against corporation tax, so it's a tax-efficient way to withdraw money from the company.

Assuming the unlikely prospect of doing no further work at all in the period, these contributions would reduce the three years future 'earnings' we've banked to around two-and-a-half before the company runs out of reserves.  

Anyway, I've been beavering away at various spreadsheets for the last couple of days.  

Banking on working....

Many, many years ago, I was a fitter on a production line for a manufacturing company and I worked on 'piecework'.

For the unenlightened, basically this meant that I was paid for each measured portion of work that I completed.  Not being particularly greedy, I never booked all the 'achieved' hours each week that I had earned, and consequently 'banked' the remaining balance for future weeks.

  

The rates for each job were set on the basis of a skilled employee completing a specified task within a specified time, and to a specified level of quality.  

The quality was always verified by an Inspector, who had to countersign the yellow docket for satisfactory completion of the task before you could book it for payment.

Well, of course, some tasks were either easier or more difficult than others.  If it was the first time a task was ever measured, say for a job on a new product line or a product variation, and you happened to be the very first one to undertake it, then you effectively '...set the rate...' for all others to follow.  In these circumstances, it was essential not to complete the job too quickly and alienate your colleagues, or potentially screw yourself in the future !  Not exactly swinging the lead, because you were under observation, but certainly not putting yourself out in quite the same way as you'd do for a previously measured job.