Tumble Dryer in the Garage

[jj4091]

petrol vapour from any petrol split or leaking into the garage....

Approximately 100% of garages are not used for vehicles, and have never had a vehicle in them in the entirety of their existence.
A fair number are too small to actually get a car into.

I doubt it is such a high figure for cars, but people do store petrol driven tools & cans of petrol in them.

 

[cjard]

Of more importance in my mind is that the heating elements in a conventional drier could be in contact with petrol vapour from any petrol split or leaking into the garage....

Why not similarly with a condensing dryer?

Kind Regards, John

In a condensing drier the air circuit that the ph eater touches is a closed loop that goes round and round between the clothes drum and the heat exchanger. The drum and clothes are heated and steam, moist air goes to the condenser where it cools and dumps its water content, then back to the drum.

I've a serious doubt that even going to the extreme of pouring an entire can of petrol all over the floor and then setting a vented dryer going will cause a problem from the heater elements.. You'd need to evaporate around 10 litres of petrol in a well sealed garage, then spark it all at once to get a good bang

 

[bernardgreen]

You'd need to evaporate around 10 litres of petrol in a well sealed garage, then spark it all at once to get a good bang

I think it is more like one litre in an average sized garage. When I was young electrical fittings had to be at least 5 feet ( or something like that height ) above the floor to avoid the risk of petrol vapour being ignited by a spark in a switch. Not an explosion but a Whoosh of flames.

Also remember that tumble driers can catch fire when the lint filter becomes clogged due to lack of regular cleaning.

 

[deadshort]

I appreciate the subject has been discussed to death but perhaps every case has to be examined on its own merit. So before spending for a failure project, it may help discuss a few facts first.

My place has no space for a tumble dryer and drying clothes in the house has become a bit of an issue for obvious reasons. We want to place a dryer in the garage, the only possible location. The garage is not attached to the house.

I am looking at buying a condensing tumble dryer, I will use one I've seen online as our test case, which says that on full load for cottons it consumes 4.2KW

At the moment the garage is supplied by a radial 2.5mm T&E with the following configuration. The CU has dual RCD and because the tails were extended to move the entire CU from under the stairs to the hallway, there is a connection block under the stairs where the old CU used to be.

The circuit has 20A MCB, the cable runs up to the block (about 4m length) and from there it goes through to the outside wall, through a conduit of about 10 meters long to a dual gang IP65 socket in the garage. There is a fused spur under the stairs and another fused spur just before the socket (these are 13A I believe).

The questions,

1. I have heard of people putting dryers in the garage, how does that work with freezing temperatures during the winter? i) can the dryer get damage from frost ii) is it possible it will seriously underperform in low ambient temperature i.e 1oC

2. Assuming (1) above is not a major issue, if the dryer wattage is around 4~4.2kW on full load*, can it be supported by the 2.5mm cable with a 20A MCB at this length/voltage drop?

*Considering that the dryer may need to run for 2 hours continuously for a cycle based on one of the programmes.

If not, what would be the best cable to run to the garage for that purpose.

Thanks

I have a condensor dryer in my garage and have never had an issues with it. You will have to remember that with your current set-up you do not have any"head room" in your supply when the dryer is in use.

Regards,

DS

 

[cjard]

You'd need to evaporate around 10 litres of petrol in a well sealed garage, then spark it all at once to get a good bang

I think it is more like one litre in an average sized garage. When I was young electrical fittings had to be at least 5 feet ( or something like that height ) above the floor to avoid the risk of petrol vapour being ignited by a spark in a switch. Not an explosion but a Whoosh of flames.

Also remember that tumble driers can catch fire when the lint filter becomes clogged due to lack of regular cleaning.

I'd come to 10 litres by calc on a garage volume and 14:1 ratio for best bang though I do concede that it might be possible to pool up a suitable volume of vapour in the lower half. I do think it unlikely for the average drafty garage and a vented dryer that it will ever pull a reasonable fuel mix over the element, or that the element will be at spark temp. That said, I'd far rather my detached garage burnt down than the house, and your very pertinent lint comment doesn't need petrol at all!

 

[stillp]

I think the greatest risk of ignition would come from a spark as the thermostat in the dryer opens.
Having said that, we don't have a problem with people starting their car in the garage, in spite of the spark in the starter solenoid and the hot exhaust manifold.

 

[bernardgreen]

we don't have a problem with people starting their car in the garage, in spite of the spark in the starter solenoid

Normally the doors would be opened before starting the car and the petrol vapour would have flowed out when the door opened. I recall seeing in a Fire Brigade's "Black Museum" a photo of fire damage in a domestic garage when a layer of petrol vapour was ignited.

 

[cjard]

So the garage is an ideal place to keep a tumbler, as long as it can be started remotely if there is dripping petrol lurking around?

I'd love to say "surely no person could be so stupid as to step into a dark room that stinks heavily of petrol, and light a match to look for the source" ...

Actually, my father used to be an apprentice engineer in a factory that made industrial wood working machines. When the acetylene bottles were delivered they would crack the valve to check they were being sold good ones. Being man-high, the usual method was to hug the bottle with one arm while operating the spanner with the other. One fella did so with a lit cigarette and burnt a triangle into his face from chin to temples..

Days before health and safety eh?

 

[masamune]

The tray of water is not the real reason for concern.

Maybe you should have a read of this guidance.
http://www.ukwhitegoods.co.uk/help/.../3022-tumble-dryers-installation-requirements

Thanks for the link!

The garage is about 4m x 3m (12sqr meters) so it should have adequate space and is also very well ventilated because the roof is not sealed where it meets the walls.

Also although temperatures do fall quite low around this time of year, most of the time it is around 5oC+, worse case worse we'll have to dry the cloths indoors when it is too cold.

 

[masamune]

Our condensing drier does not have a heat pump neither does it exhaust any humidity into the room where it is located. It does warm up that room.
It has two separate air circuits. Firstly circulating warmed air through the drum to dry the clothes and secondly an external air circuit through a heat exchanger that cools the warm wet air and so condenses out the water in it and collects it in a container. It doesn't like being shut in a small room either as the cooling airflow warms up and it doesn't condense properly. It's fast too and runs for far less time than I expected it to.

Of more importance in my mind is that the heating elements in a conventional drier could be in contact with petrol vapour from any petrol split or leaking into the garage....

What is your condensing dryer?

There is no fumes of petrol in the garage, everything is stored and sealed...

 

[masamune]

I have a condensor dryer in my garage and have never had an issues with it. You will have to remember that with your current set-up you do not have any"head room" in your supply when the dryer is in use.

Regards,

DS

What condensing dryer do you have?

I agree, there is no room for parallel work (power tools or other things) while it is in operation, but it's not a big deal I will just let it finish it's cycle or pause it if in need of any urgent use of the garage supply.

*Note: the garage is not used for parking a vehicle as guessed by people earlier.

 

[masamune]

The main reason I wanted to buy a condensing dryer is that I don't want to have to drill a big hole through the pre-constructed concrete panels caging the garage.

On the other hand it is performance I am concerned about as many people have argued that condensing dryers require a lot longer to dry cloths on heavy load.

 

[deadshort]

I have a condensor dryer in my garage and have never had an issues with it. You will have to remember that with your current set-up you do not have any"head room" in your supply when the dryer is in use.

Regards,

DS

What condensing dryer do you have?

I agree, there is no room for parallel work (power tools or other things) while it is in operation, but it's not a big deal I will just let it finish it's cycle or pause it if in need of any urgent use of the garage supply.

*Note: the garage is not used for parking a vehicle as guessed by people earlier.

I have a Bosch classic xx 7.

Regards,

DS

 

[cjard]

.

Also although temperatures do fall quite low around this time of year, most of the time it is around 5oC+, worse case worse we'll have to dry the cloths indoors when it is too cold.

I don't think you'll ever have a problem with the cold affecting your ability to dry the clothes, and indeed with a condenser it will help. Drying indoors brings with it a host of other trouble in winter times when doors and windows are shut to keep the heat in..

People who report condensers taking a long time might well be running hem in small utility rooms. As the drier draws world air through the condenser unit, the cold world air causes the hot moist air in the dryer loop to condense the water out as it cools, but the heat has to go somewhere.. And thats into the world air that is passing through the heat exchanger. As a result, if the utility room isn't well ventilated it warms up, which means warmed air is going through the condenser, which means it doesn't condense as efficiently

The current top rated (by Which magazine) heat pump condenser dryer (heat pump ones run cooler) is a Bosch WTW87560GB at 610 quid. That said if your eaves are well vented, you needn't fit a hole in the wall.. Just run the tumbler snake up and of the soffit

 

[flameport]

is a Bosch WTW87560GB at 610 quid.

Why would anyone pay that much, or even anywhere near that for a tumble dryer?