I've got a small, insulated workshop - about 8' x 8' - and I keep it at 50F or
above with a 1.5Kw thermostatically controlled convector heater. I turn this up
to a nice working heat when working in the place. I've had no problems with
surface rust on tools and steel.
Keep your workshop at a constant temperature and you wont have to worry
about the dew point.
as everthing equalizes in temperature in the workshop.......the
possiblity of condencation will vanish.
I sugest 15c
I have a kerosene/diesel jet engine type space heater on a thermostat
set to 15c......
masses of condencation for the first 2 !/2 days....then when everything
had equalised walls and machines ......all condencation stopped.
and has not been back since.
used lots of fuel to get it up to this temp.....but once it had
stabilised it is now only using a 1-3 gallons a week
also put vents in the apex.....to bleed off the hottest portion of the
air that also contains the most moisture...
not looked back since.
all the best...mark
ps see my ebay ad
if you want some heavy duty radiators
In message , John
It is temperature VARIATION that is the problem. As a given sample of
air is cooled so its capacity to hold water vapour decreases (humidity
increases). The dew point is the temperature at which that sample of air
can no longer hold water vapour and thus starts to shed water as dew
(100% relative humidity). Hence the need to try to stabilise temperature
by good insulation.
At one time, in a totally uninsulated small shed, I kept a lathe totally
free from corrosion by draping a couple blankets over it and using a 25
watt light bulb on the floor directly underneath and running 24/7. Boxed
tools also survived but unprotected tools and stock metal did not.
I have now moved up to a well insulated wooden shed which has double
glazed window panes. Hygrometers (humidity gauges) are ridiculously
cheap at any gardening centre. As belt and braces I have a fan heater
with the thermostat permanently set at the lowest value (frost-stat)
together with a hygrometer and a cheap de-humidifier bought at a DIY
store. I am pretty sure that the de-humidifier might well have been a
step too far, finding a suitable level for the thermostat by checking
the hygrometer at regular intervals could well be good enough.
The workshop is a converted refrigerated truck body (6" insulation), I have
barn doors at rear but have split the box in two with stud-wall...looks like
I should invest in an oil heater then, monitor the humidity and aim to keep
the temp between 10-15 C based on humidity.
I'd be a little cautious about a paraffin heater, they produce over a gallon of
water for each gallon of fuel burnt, produce fumes and are potentially
If you have no other alternatives then go for it, but an electric background
heater or Dimplex type radiator would be preferable IMO.
I use a 200l (45gallon) barrel converted into a fire.
It's outside my (2 portacabin, 20' Square) shed, in a wood/metal box -
I pull hot air from the box through a piece of 4" pipe into the shed.
I have a blower attached to do this but I've never needed it.
The smoke goes through a chimney up over the roof well away from the
air intake - next project is to feed the smoke into a smaller reburner
to increase the efficiency, or at least make it burn a bit cleaner.
If I load the burner up with old pallet wood, it burns for about
48hrs, and holds the temperature in the shed at about 20C
I'll put up some pictures tonight if I get time.
In message , John
An electric heater produces 'dry' heat.
The products of combustion of an oil heater are carbon dioxide and water
vapour. This will produce a high humidity level and thus a high risk of
dew point condensation should the heater fail (run out of fuel). The
carbon dioxide will ensure that the condensate is mildly acidic, ideal
for making rust.
If you use an oil heater vent the products of combustion to outside.
I use a 3kW wall mounted fan heater in my workshop which is a standard
prefab concrete single garage, I have it wired up to a frost stat set
to 7° C with a conactor relay to switch the power on. The walls are all
clad with 20mm thick marine ply for insulation, which also gives me
something to screw shelves onto.
This set up does not cost an arm and a leg to run, and so far no rust
problems have re-occurred since I did this. During the summer months
the heater never comes on, and the temperature remains fairly stable
My first post here.... figures it would be about workshops. :)
I heat my workshop with a high efficiency gas furnace. Even though
maintain temperature within a couple degrees, I found moisture wa
still an issue. Now that I run a dehumidifier, I was surprised at th
amount of water it pulls from the air. I hooked it up to a garden hos
and was having soil erosiion issues from the amount of water it wa
extracting. Southern Ontario is definitely a humid area. :
My shed is wood construction with polystyrene between the outside an
the hardboard cladding inside.For the last sixteen years I have had a
electric storage heater on economy 7.
I don't have rust problems and I don't have to wait while it warms u
in the winter.
Doesn't cost me a penny to run.....Gert pays the electric bill. :cool
Allan Waterfall's Profile:
My answer to condensation problems is ventilation...
I have an electric 3 kW fan heater rigged to a control box that switches on
at 80 % humidity or 2 C. ( reset to 20 C when I'm working )
Heating to this low level is not expensive, and keeps the pipes from
freezing and the humidity condition is almost never met.
My workshop has a vent at each end, and this prevents humidity building up
in the workshop itself.
The reason this works is the outside air once it gets bellow 0 C it is dry,
so if the machines are slightly warm at the start of the night as the
outside air cools, and ventilation then brings in dry air, a small amount of
heat lets this air actually absorb any surface moisture, and it's then let
If the warm air that picked up moisture ( from the suds tank and anything
else remotely damp) during the day is still in the workshop as it cools it's
going to try to drop it's moisture... Its better to get it out of the
The only alternative is to keep it hot.. so it absorbs more moisture...
I have had no problems with condensation over the last three winters and the
amount of water my dehumidifier pulled out of the air was very small.
Any heater that leaves combustion products in the workshop is adding to the
problem, it's the perfect way to make really humid air.
I agree to a point - the type I use don't work well at low temperatures, so
its rated to produce upto 2 gallons of water per 24 hours, the sucker punch
is "at 30C". At 3C the output is very low indeed.
I'd also concur with the posts regarding "dry" heat sources. Gas heaters
(Calor) produce large quantities of water.
The real solution is to build a workshop that is naturally dry! Cavity
walls, properly insulated and ventilated.