Home garage heating.

My garage is brick and attached to the side of the house. One car size with a concrete floor.

Please advise as to what may be the best option to heat ones home garage.

What would be the cheapest solution.

Many thanks for the help.

My opinion is biased as I live in the country but a wood burner. Pallets are a good source of fuel. It is quite easy to make one if you have access to welding equipment.. Noel.

Hi Cedric,

The first thing I would do is insulate the walls. This can either be a rigid foam board glued to the wall with a few screws to hold it in place, or build a timber framework to create an internal wall with insulation, more choice with the method, and finish it of with a board. You have a choice of boards depending on how tough you need the walls to be. Plasterboard, chipboard or stirling board would do the job. You will probably have to include a vapour membrane in the constructio. Then you can think about heat.

Lee

Hi Cedric,

I seem to have posted this twice. Now deleted.

Lee

Edited By lee webster on 16/01/2023 09:41:23

^^^^ This. The better you can insulate it, the easier and cheaper it is to heat. Insulating the ceiling is important too. And some kind of floor covering or even a false floor with insulation between it and the cold concrete is good too. And put your main work area up against the wall that adjoins the house. That will be the warmest part of the workshop.

For your climate in the UK you will need to look at humidity/moisture control too. Not just to stop corrosion of machines and tools etc but if you can knock the relative humidity down to 50 per cent or so, it takes less heat to achieve a comfortable temperature. Too much humidity and you will need to heat the shop to a higher temperature to feel comfortable. (Likewise, too little humidity and the perspiration drying off your skin will make you feel colder and so again more heat will be needed.) It is worth installing a wall thermometer with relative humidity gauge to monitor it. And dehumidifiers seem to be a thing in some UK workshops from what I see on the forum.

I think I would start by...
Making sure doors are draught proof and well insulated
If possible, put in a plasterboard ceiling
Insulate above the ceiling or inside the roof if not.
Think about the walls like Lee said.
Less volume and heat loss, then you need less heat.
Make your mind up what you are going to do in there - what temperature you need and when.
If often, then just a radiator with a thermostat off the home central heating?
If not so often - a simple fan heater?
For me, not propane - they stink and produce loads of water.
An electric tube heater if you just want to increase the minimum temperature.
If working in there 17deg. is OK for me.

It all boils down to what you want to use it for.

The first thing to do is to read all the posts on this forum for the last 3 months, We have covered this topic every week, over and over again. You can do this in the warm of your house thus saving 3 days of heating in the garage.

Shouldn't need to warn but be careful if you're going down the log burner trail. DON'T burn treated wood.

Regards Ian.

Yes, nice one

First step is to insulate all surfaces as best you can, then as the garage is attached to the house my preferred option would be to install a radiator off the house system and control its output with a thermostatic valve. It will put up your heating bills but whatever heat source you use will cost money to run and using the house system is far more convenient. When I still lived at home in the early 60’s my Dad installed gas fired central heating in our house and as the garage was attached to the house he had a rad installed there. My passion at that time was canoeing and I built my own canoe one winter and I was so glad that the garage was heated whilst I was busy building. Dave W

It is quite easy to make one if you have access to welding equipment..

But not legal. New wood burner installations are required to be "EcoDesign compliant" & EcoDesign stoves are not inexpensive.

Heat treated pallet wood is probably OK, but not chemically treated wood. Even the heat treated stuff is probably not legal, as solid fuels are supposed to be "Ready to Burn" certified now.

Having said that, my vehicle diesel air heater is probably of dubious legality - though red diesel is an approved heating fuel.

As your gagrage is attached to the house, i would go with "insulate, insulate some more & add a radiator off the house CH" - assuming that you have a wet CH system in the house.

Nigel B.

Sharp changes of temperature in an outside building like that will create condensation .

A sure way to turn steel to rust.

If it is open to the roof, install a plasterboard ceiling with insulation.

For the floor, I have bought some interlocking rubber mats from Halfords - they are about 10mm thick. They provide some insulation and are more comfortable than standing on bare concrete.

If you can, install a radiator fed from the house CH system. I have just done this and fitted a motorised radiator thermostat to it. I can control the temperature using an app on my phone so it only needs to be on when I want it and can be set to heat up in advance of going to the workshop. I have them on all the radiators ( it is the ‘Wiser home’ system from Schneider). For this particular system you need to replace your traditional CH timer with the Wiser one, but you can buy other brands that are free standing.

Stuart

Hence the need for humidity control as well as just heating.

I did a thorough job insulating doors, walls, ceiling. I didn't do the concrete floor yet but place is very cozy without it so I would say it isn't essential.

A self closing door is a good idea but at least a door that slams shut with draught exclusion.

I use a mini fan heater to take the edge off quickly, and an infrared to make me feel warm while waiting. It is a detatched double garage - half an hour of heat lasts all day for a weekend like we just had.

I also have a FLIR infrared camera to identify weak spots in insulation. Very useful once or twice a year (also good for electicals and finding the next thing that might let the smoke out.)

Edited By jaCK Hobson on 16/01/2023 12:19:51

As everyone says, INSULATE , walls. ceiling, floor, door, (Prevents heat loss and reduces the volume to be heated ) A well insulated shop will warm up faster, and use less energy to maintain the temperature.

If it runs frequently enough, pipe another radiator from the central heating, if you have it.

Next best,an electric fan heater. Convectors tend to be slow, Radiants may warm you, but not the machine so well, so rusting may still occur.

The objective is to keep the air temperature above the dew point.

Combustion heaters (:Liquid or solid fuelled ) produce water vapour, so the exhaust must be fed to the outside. Plus any leaks risk gassing you with carbon monoxide. AND they must have ventilation for the combustion air to come in.

A certain amount of ventilation is important. You exhale water vapour, you perspire, so leave a small vent at ground level. (under the Up and Over door? ) for the moist air to escape.

Howard

How good is the existing insulation? My garage/workshop is part of the house, with bedroom over. This means it has a double cavity wall which has been foam insulated inside, and the floor is damp-proofed. Unless it's very cold, I don't heat at all. Instead, heavy coat until the lights take the chill off. Brightly lit, 6x fluorescent tubes.

Wouldn't work in a thin-skinned lean-to type garage sat on a concrete pad, or a simple shed. These are diabolically poor.

My advice, don't start by heating. Minor reason is the cost, because lots of energy is wasted because most of the heat escapes uselessly. But the major reason is repeatedly heating and cooling a workshop is the very best way quickly rusting tools! Cycling the air temperature causes condensation. Instead, start by insulating as much as possible, plus everything you can think of to exclude damp.

Then heat as necessary for comfort. Choices:

• Electric for clean easy convenience. For cheapness, wood burner or similar, but remember the installation cost is higher than an electric heater, and they have to be stoked and maintained. Not good if you pop in and out of the workshop rather than work long hours in one
• avoid portable electric fan heaters and free-standing paraffin heaters - fire and trip hazard
• oil-filled electric OK, but they tend to warm the workshop top down. Hot air rises, so it takes a while for heat to reach floor level, which it might never do if the roof is poorly insulated
• radiant electric heaters emit radiation that warms solid objects rather than air. These feel warmer, but a good part of the energy is soaked up by the walls and equipment. My gut feel though is these are good for workshops. Safe, easy install, the benefit is felt instantly, and condensation is less likely because air is warmed last, not first.
• Never heat by combustion unless there's an external chimney!
• A combustion heater fed by air inside the room is inefficient because it pulls cold air in from outside. May not matter if fuel is cheap.
• Diesel heaters have become popular for heating workshops, but although oil is cheap, installation isn't. They require an external air intake and outlet, plus a 12V power supply. They blow room air over a heat-exchanger, and the distribution pipework can be aimed to maximise benefit. Fuel efficient, but more likely to cause condensation than a radiant electric heater. Again, much more suitable for long sessions in cold weather than short ones. Installation advice is shaky: aimed mainly at vehicles, the instructions provided vary from extremely basic, to good, but many are indifferent. Lots of youtube installation examples, but it's up to you to filter these! Most youtube technical videos are produced by amateurs, who don't have their efforts checked before publication. Consequently an uncomfortably high proportion contain errors, bad practice, or miss important details. Not a problem when shortcomings are obvious, but potentially nasty when they go unnoticed. Treat anything on youtube with suspicion, remembering that it's your problem if taking their advice burns the house down. The people who publish duff advice on the internet have no responsibility.

Dave

My integral single car garage protrudes half from the house. The part built out from the house has a uninsulated roof with cement board on the inside. The up and over door I covered with foil insulation and this made enough difference that I manage without further insulation. Some heat does come from the wall mounted combi boiler which is in the garage but not much as it is normally off while I am in there. If I was staying I would insulate the single brick external wall which is beyond the house and add insulation to the roof. Additional heat in the form of a small electric heater would be enough for occasional use.

For the last couple of weeks, my well-insulated and draught-free workshop has been mostly heated by the dehumidifier (375W) which has been run on a timer, for one hour during the night, on E7 power. The temperature had dropped below 10 Celsius this last couple of days, so the diesel air heater was fired up for an hour yesterday evening. Not yet checked the temperature today. The heater had been used for a few minutes on a couple of occasions this year, so far, to warm it sufficiently while working in there.

Apart from the temperature being adequate, the humidity has been around 70%, or less, during this time.

Cost, so far this year, is about £1.30 for leccy and less than a litre of diesel. Diesel usage was rather more during the cold spell, but not excessive, IMO.

I have a single skin brick garage, but I've insulated it with 3" polystyrene on the walls and 8" fibre glass above the ceiling. Heat then provided by 2 kW balanced flue gas heater. Run on full for 15 minutes then turned right down gets the place nice and warm. Having the place too cold means I keep dropping fiddly little things, so not worth it. The gas heater is designed for domestic use, came surplus from a domestic rethink. Floor is concrete flags with asphalt to keep the damp down, then 1"polystyrene topped with flooring grade chipboard. Had to cut holes and provide hard points for the heavy machines. 

Edited By duncan webster on 16/01/2023 14:41:32

Edited By duncan webster on 16/01/2023 14:41:55