Home brew dog kennel heating pads?

[Chris Wilson]

These are available commercially, but are quite costly, so I got around to considering building some. I am in the UK on 240 volt mains and need five pads to go in outside wooden kennels in separate dog runs. The concept is two metal plates in a sandwich about 4 feet long by 3 feet wide. Within the sandwich is a heating element.

My first thought is run them on 240 volt AC, maybe through an isolation transformer, rather than dropping down to say 12 V AC. For a heating element what about several metal clad power resistors screwd under the top plate? I envisage about 25 Watts of heat energy warmth being enough versus running costs. The plates will of course be well grounded using armored cable. How many resistors to give a decent heat spread through say 3mm thick alloy plate for the top of the sandwich construction, with thinner closing the bottom? If I went the safety route how inefficient would it become on say 12 Volts using the transformer from a big automotive jump / charger I have redundant?

Any ideas for other types of heating element welcome and just general thoughts? The kennels are quite far apart, and mains power is available very close to two of the runs with two kennels in one run and a single kennel in the other run,  which are directly alongside two sides of a big steel building. The other run with two kennels in it is separately located and about 35 feet from the steel building. The steel building has mains power. It's quite possible to easily bury armored cable from the steel building to the separate run, as the ground between is earthen.

Thanks for reading!

[nali]

How about trace heating cable?

[Towger]

How about trace heating cable?

I used this for a rabbit hutch.  The advantage is it self regulating.

[CJay]

Brewer's fermentation pads perhaps?

Maybe this stuff:

https://totaltiles.co.uk/underfloor-heating-mat-150w.html?gclid=Cj0KEQjwmri_BRCZpaHkuIH75_IBEiQAIG0rIWgvXURSFfUKE9XEmy-Kd1rwivJqpYgllFPkSUFYopIaAnih8P8HAQ

Looks cheap enough to experiment with

[Marco]

A square meter of heating film for floors costs ~15$ from our friends in China.

[setq]

They eat dogs there. Make sure you buy the right ones

[Cerebus]

I read that as "Home brew dog. Kennel heating pads?" and I thought "Yes, the least you can do is get your dog a kennel heating pad if he is brewing beer for you." 

I think the things you have to consider are "How is it going to behave ..."

• If peed on
• If puked on
• If chewed
• In very high external temperatures (direct sun on the kennel)
• In very low external temperatures (cold enough to freeze the pee pooling on the mat)

I'd start by looking at the self regulating type of heater tapes and cables, and look for ones I could drive from isolated low voltage. You might have to be quite cunning with protection circuitry to adequately cope with some of the risks outlined above.

[CatalinaWOW]

In my youth we always just used an incandescant bulb to heat the dogs kennel in cold weather.  Temps were as low as -30 C.  Simple and cheap.  One of the few times the low efficiency of an incandescant was good.  The lights were left on all night, and wattage was chosen to keep the temperature "warm enough".  The dogs had lots of bedding to burrow in so it wasn't necessary to get up to human comfortable temperatures.

Even now that incandescants are getting harder to find and going up in price it may be a good option.  Robust sockets designed for rough outdoor use are readily available.

[Chris Wilson]

Thanks for the great replies, the pipe heating cable looks a simple and cost effective method, I will order some and try a bit of experimentation, your time is appreciated everybody