Heated Windscreen Washer

[clivehorridge]

Time ago, I set about making a heat exchanger to warm up washer water in a jacket around on of the heater pipes.

After making it, it sat in the shed, so as winter is coming, I fitted it today, hurrah!





It's very simple, just a straight through 13mm pipe with some 22mm sleeved over, using reducers. Some copper brake pipe soldered in to take the washer tubes.

Works a treat.

 

[StarCruiser]

Neat! Is that run off the rear heater connections…?

Like it very much. Might even do the same. [emoji6]

 

[StarCruiser]

I get it, I had thought you had just run the small bore pipe through the main flow but you've effectively got a shell and tube heat exchanger there with the small bore just as connections to the jacket that would be full of screen wash. So rather than a flash heater you are preheating a 'slug' of screen wash.

Um, pardon me for asking, but won't there be a chance of cracking the windscreen? Or will it lose enough heat between nozzle and screen not to be a problem I wonder?

 

[Towpack]

I was wondering that too. With the engine fully warmed up the initial squirt of washer fluid could be 80-90degC. If it loses 20deg it could still be 60-70deg. I had a similar although much more basic setup on a car years ago built up from an article in Car Mechanics I think it was. Just a length of copper brake pipe wrapped round a convenient coolant hose for a few turns and linked up with plastic washer tubing. The water used come out of the jets steaming in cold weather but never felt that hot when hand tested. It didn't cure the problem of the jets themselves freezing up overnight though.

 

[adrianr]

Nicely done. I wrapped about 6 feet of plastic hose with the washer fluid in it around the heater hose. Cable tied the ends.

Cut holes in the soundproofing in the bonnet underneath the washer jets to get engine bay heat into them. It does warm up the area of the jets pretty quickly. Some vodka in the washer bottle also helps it not freeze.

 

[clivehorridge]

Thanks for the observations guys.

I've used several versions of this this device on several cars in the past and I've never cracked a screen!

On more refined models, I've insulated the whole thing in domestic pipe wrap, so I would have thought that one would have been a "cracker", if any were...

There must be oodles of heat loss in the plastic jet pipes. Before I cobbled this up, I had a meter and a half of tubing wrapped around one of the hoses which worked a bit, but the cold water soon came through.

I also use windscreen washer liquid from the fuel station, supposed to be good down to -30C. It has frozen at the jets on occasions, but only when extremely cold, say -20C and less.

There's a non-return valve on this too, which stops the exchanger draining back into the reservoir bottle.

We'll see how it goes. Didn't cost much to put together, just a few plumbing bits and pieces. The trick is to ream out the 'stop' in the reducers so that the 13mm pipe goes right through them.

Yes Rich, you got it, it just creates a copper jacket around the heater pipe. I don't think it matters which one, they all feel as warm as each other to me when the engine is up to heat.

It takes about 8 minutes for my heater to work driving the truck from cold at about zero outside.

 

[StarCruiser]

Well that sounds pretty conclusive I'd say if you've done it before.

On the jets, I had a thought about this. There's a selection of silicone heaters on eBay of varying wattages. I had the idea that suitably sized ones could be glued to the underside of the bonnet ideally around but adjacent to each washer jet. The heat, if enough would feed through to the jets and defrost them in a short time. Well, that's the theory.

Like this one
http://www.ebay.co.uk/ulk/itm/272039712593

 

[clivehorridge]

Well that sounds pretty conclusive I'd say if you've done it before.

On the jets, I had a thought about this. There's a selection of silicone heaters on eBay of varying wattages. I had the idea that suitably sized ones could be glued to the underside of the bonnet ideally around but adjacent to each washer jet. The heat, if enough would feed through to the jets and defrost them in a short time. Well, that's the theory.

Like this one
http://www.ebay.co.uk/ulk/itm/272039712593

Good idea.

The trouble is, the jets are encased in plastic, which is one of the poorest materials for conducting heat. Still, they wouldn't need much just to stay at or above zero...

 

[StarCruiser]

Agreed, it was more to give them their own little microclimate in effect. [emoji4]

 

[frank rabbets]

My 1989 audi coupe 80 had heated jet nozzles but they were not connected on UK models !! It is therefore possible to get a heated jet nozzle but one may have to modify the holes in the bonnet.

 

[StarCruiser]

There's heated nozzles on eBay [emoji4] various ones for various cars. Not expensive either.

 

[clivehorridge]

There's heated nozzles on eBay [emoji4] various ones for various cars. Not expensive either.

If you've no objection to green oval parts on your cruiser....

 

[StarCruiser]

What? And have it infect the whole car with breakdown vibes? Not on your Nellie! I was thinking more BMW or the like. Though i didn't spend much time on it TBH.

 

[clivehorridge]

What? And have it infect the whole care with breakdown vibes? Not on your Nellie! I was thinking more BMW or the like. Though i didn't spend much time on it TBH.

I thought that may prompt a response

Indeed, BMW and I think VW have similar devices, but the idea is neat...

 

[chapel gate]

Nice idea clive. My old cav 4x4 turbo had heated washer jets that came on with the heated mirrors. There is a device called a hotshot iirc that heats the washer water. I use neat screenwash in winter.

 

[clivehorridge]

Nice idea clive. My old cav 4x4 turbo had heated washer jets that came on with the heated mirrors. There is a device called a hotshot iirc that heats the washer water. I use neat screenwash in winter.

Heating the whole washer bottle is the ultimate, but there might be a tendency for ctystals or other gunge to propagate in a warm water reservoir, JMO.

Yep, here they do a summer mix, just a degreaser and cleaner basically, but in the winter the -30C stuff is quite effective when used neat.

 

[clivehorridge]

Just had a little read up on "Heat Shot", it seems to be positioned between the reservoir and the jets, similar to mine, but almost instant, 30 seconds instead of 8-10 minutes!

Nice.