VAWTs and workshop heating

[Steve Maskery]

Evening chaps.

The cold never used to bother me much, but as tempus fugits more and more, I'd prefer it if my workshop were a bit cosier.

It's pretty well insulated, for a shed, but it is a large space with a ceiling 11ft in the centre. It's been down to 7C at the coldest.

I don't want to be burning anything that produces water vapour, and although I have a 2kw electric space heater, I'm a bit concerned at how much it would cost me to use it. My energy bill is already more than 10% of my monthly pension.

I saw a turbine today in a garden, and it got me thinking. My limited understanding is that Horizontal Axis Wind Turbines (HAWTs) are more efficient than Vertical ones (VAWTs), but VAWTs do take up less space and would be easy to fit to my workshop.

What if I bought something like this

and one of these

Would it work or would I be wasting my money? I know that 750W is not very much, but it could run pretty much constantly, and I'm looking for temperatures in the teens, not a sauna.

Thoughts from those more knowledgeable that I am would be very welcome.

 

[Yojevol]

I would be extremely skeptical, Steve. The fundamental problem is that you need this to run at full pelt all the time your in the w/s. Unfortunately the occasions when the wind is blowing sufficiently to provide full power will be seldom. Ironically when the cold wind is blowing outside you're probably be suffering from draughts taking the precious heat away. Also on those lovely still crispy mornings you won't have any wind to keep it going.
Years ago, in the early days of wind power, I was involved in the development of commercial, ie, big, vertical axis generators. In theory they looked an attractive proposition because of their simplicity, but the engineering problems were insurmountable which is why you only see horizontal machines on today's wind farms. There are plenty of vertical axis machines nowadays but they are all relatively small. Probably good for small installations when combined with battery storage and/or with solar panels
Brian
PS. A 750W heater at 24V is going to need some hefty cabling

 

[Beau]

The phrase you usually here for any small turbine near buildings is a chocolate teapot. The simply dont work well in the real world. There was a HAWT from B and Q called the windsave. It was supposed to work in the urban environment producing 1kWh. It was a disaster as no turbine likes the turbulence that is inevitable around buildings. Unless you live on a remote island with a clear fetch over the sea avoid. Have a look on the Navitron forum where there are plenty of off gridders who have dabbled with small turbines.

 

[nev]

An alternative may be a conventional gas combi boiler and rads. LPG conversion kit on the boiler and a 47kg gas bottle outside. This is what my old 2.5 bed house had (7 rads) and we'd average 12 bottles a year at 50 quid a bottle. Obviously you wouldn't be occupying the space for the same amount of time so I reckon a bottle would last you a few months, a used boiler and some big rads from eBay or your local rag, regulator and pigtails from your local caravan shop or plumbing supplies One short connection from regulator to boiler for gas man to do, and away you go.

 

[Steve Maskery]

Sigh.
Not at all what I wanted to hear, of course, but thank you all very much indeed.
I think I'll just buy a thicker vest!

S

 

[Peterm1000]

I think I have the solution...

 

[RobinBHM]

Air source hest pump?

https://www.aircondirect.co.uk/p/869238 ... ket-bundle

 

[Sheffield Tony]

I thought vertical axis turbines like the Savonius rotor are more tolerant of turbulent flows - they don't need to turn to face the wind. But the output power varies with the cube of wind speed, so unless there is some storage, you might have to work only on windy days

I can't figure how big the turbine poctured is, but according to Wikipedia the output power of something the size of an oil drum would be about 180W, so there might be some "optimism" going on here.

 

[MikeG.]

....... But the output power varies with the cube of wind speed........

...........and with the swept area, which varies with the square of the diameter. Double the diameter of the swept area (ie the length of the blades), you'll get four times the power. Which is why wind turbines are getting bigger and bigger. Also, wind speed doubles above 10 metres because of the disruption and turbulence at ground level, and in an urban environment, that 10 metres starts at roof height, not ground level.

It's a non-starter, Steve. Your choice is going to boil down to electric heating, a wood burning stove, or a small boiler with radiators.

 

[Chrispy]

I've just about made the decision to go for infrared electric heaters hung from the ceiling, for the last two winters I've used a portable one and although it takes a bit of getting used to it does work even when I'm spraying with large extraction fan and door open. Yes you have the leccy bill but no annual service bill as with gas or oil.

 

[OscarG]

Steve, you said your workshop is well insulated. Is it possible to increase the insulation further?

Something cheap and easy like this > https://www.wickes.co.uk/Wickes-Thermal ... m/p/210022

I don’t claim to be any expert but we used this stuff on the ceiling in my dad’s garage when it was bloody freezing in there and it made a huge difference.

One added benefit is because it’s shiny it makes the workshop brighter!

 

[Doug B]

A cheaper option would be to run a couple of rads off your house combination boiler Steve, you’d may have to put a supplementary expansion vessel on the system dependant on the systems present capacity but they are not expensive, run a couple of insulated pipes in a duct & fit a couple of rads.

 

[RogerS]

Sigh.
Not at all what I wanted to hear, of course, but thank you all very much indeed.
I think I'll just buy a thicker vest!

S

Nev's idea definitely has legs, Steve. I'd not dismiss it out of hand.

 

[John Brown]

https://www.dailymail.co.uk/sciencetech ... actor.html

Have a word with this lad.
You can probably offset the initial cost by heating the rest of the street.

 

[RogerS]

A cheaper option would be to run a couple of rads off your house combination boiler Steve, you’d may have to put a supplementary expansion vessel on the system dependant on the systems present capacity but they are not expensive, run a couple of insulated pipes in a duct & fit a couple of rads.

Nice idea, Doug, but how long is the run ? Potentially a lot of heat loss.

 

[Doug B]

A cheaper option would be to run a couple of rads off your house combination boiler Steve, you’d may have to put a supplementary expansion vessel on the system dependant on the systems present capacity but they are not expensive, run a couple of insulated pipes in a duct & fit a couple of rads.

Nice idea, Doug, but how long is the run ? Potentially a lot of heat loss.

I’ve never found heat loss a problem Rog though my pipes are well insulated & run in a soil pipe duct. I never noticed any naked increase in gas usage after adding the 3 shop rads so it couldn’t have made a big difference to the running of the system

 

[Steve Maskery]

Thank you all for your input. I'm looking out of the window and see that it blowing a hoolie, and I'm thinking, "I wish I could harness that!". But I also remember that I have never lived anywhere as foggy as here, and fog and wind are never bedfellows.
Thank you all for preventing me from wasting my money. I think I'll spend it on higher heating bills. Or just lock up the workshop and spend the winters in Spain, like my mate Stuart does.

 

[NickM]

fog and wind are never bedfellows.

I grew up in Guernsey and gale force fog was a local speciality!

 

[Phil Pascoe]

:lol: I went out with a girl whose family were Londoners - her mother used to say she never understood why anyone in Cornwall used an umbrella as the rain was always horizontal.

 

[Jonzjob]

Talking of Navitron, you could get one of these jobbies?

https://www.navitron.org.uk/air-heater- ... ce-heating

They don't work on sunlight as such but on the UV it produces so it will work even on cloudy days, as long as it ain't toooo cloudy? If you speak to the right people you could possibly get a discount on that too :shock:

As some know we have just moved house and in our new place there was a solar air heater in the garage wall. Now it's on the outside of my new workshop. Similar to this, same principle, but smaller

https://www.123zeroenergy.com/how-it-wo ... -info.html

Once again it works from UV so direct sunlight is not essential but it is a lot more efficient. There's a load of DIY info if you do a search for 'solar air heating'.