Man Cave: Modified

Man Cave: Modified

Getting warm in San Francisco is almost always a challenge, and even a high rent doesn’t guarantee your apartment will include adequate heat. Buildings are old, uninsulated, and drafty—the triple threat for those who like to be able to comfortably walk about their apartment in our overly-valued draconian conditions—if they even have heat.

There is no cold.

I have a small man cave. It is a small shed that got dragged across my backyard and attached to my apartment sometime around 1920. It doesn’t have heat at all. Through the years I’ve tried heating it with various space heaters, but it’s so drafty the most that’s provided is waves of warm air interspersed with Arctic blasts. I also can’t sleep with a fan clicking on and off through the night—it’s awful. Ultimately, I’ve found that the only way to effectively heat the room is with radiant heaters. They make all the surfaces of the room feel warm so my body heat is no longer the primary heat source.

There is only heat and an absence of heat.

The Matts

About 12 years ago I stumbled onto FlexWatt heat tape. It’s sold for heating reptiles, but my cat likes it, too. You order the stuff by the foot, cut it to the appropriate length, then wire it up. I use aluminum snap rivets to insert wire posts, and then seal them with silicone (that way if my cat knocks over a glass of water, the floor won’t be electrified). At 20 watts/lineal foot, it can take quite a bit to maintain comfort on the coldest of nights. I have several sections under my rugs.

A couple of years ago, I realized I could apply the FlexWatt matts behind a painting I have. The additional coverage really helped warm up that side of the man cave so I could sit at my desk longer, and provided an attractive way to transform everyday possessions into functional heating units.

A Word to the Wise

The heat tape says something about not being stuffed under stuff. I have completely disregarded that for 12 years using it primarily under rugs with no ill affect. It runs pretty cool and hey! It’s designed to get warm after all. Covering FlexWatt with material has been fine, but I wouldn’t recommend double-layering the stuff. Of course this article is provided for expositional purposes only documenting my experience and in no way should influence your choice or activity.

Modern Thermostat

Many older homes utilize millivolt heating systems. Especially in the Bay Area, these are often wall heaters, although sometimes they may be in the floor heaters as well. Getting these plugged into a modern learning thermostat isn’t too challenging, but does involve jumping through a couple of extra hoops. There is a great tutorial on getting these systems plugged into a Nest Learning Thermostat over here using an off-the-shelf Honeywell relay box.

Life is hard when you can’t control your heater with Siri. Your man cave will be the laughing stock of the town and your friends will never come visit you if you have to get up to change the temperature. Getting Siri for my heat mats was imperative to their success.

It turns out the Nest thermostat does not like to operate without controlling something. It will give you an alert that it is not experiencing the associated voltage drop with the heating system when it tries to switch it on if you power it off a 24VAC brick with no system plugged in, and eventually errors out and gives up. When I first designed my heating matts, I designed them to operate off two iDevices wall plugs. That way each zone could operate independently. This let me setup the painting heater as an auxiliary source for those colder evenings. I started that way but eventually just programmed everything to operate together. This meant that the room stayed more evenly warm and also reduced the duty cycle on the under-rug heaters. At this point, the only real advantage of separate iDevices plugs was handling the total wattage and avoiding having wires snaked all over the room to get to the painting heater.

Additionally, Nest does not currently support HomeKit. There is a Nest HomeKit Bridge in Node.js for just such occasions, but it’s annoying to have to run yet another box to handle functions I feel my allegedly smart thermostat should already take care of. I get easily indignant over such issues. Because of the lack of HomeKit and the inability to operate without actually having something plugged in, I went with a Honeywell Lyric Round.

Further Issues

I also encountered an occasional (although admittedly rare and pretty unannoying) issue where my thermostat wouldn’t trigger my heater on due with the HomeKit cues, probably due to some network or wakefulness issue with my AppleTV. Looking back, things could have been smoother had I used a Honeywell Relay Box to control the main under-rug heat matts directly with the thermostat and used an iDevices plug only for the auxiliary painting heater. Or, sized up the under heater rugs to control the whole system entirely with one Honeywell relay box and skip having to purchase and configure the iDevices plugs altogether.


No matter how much you’re paying for space, you can always pay more to make peripheral spaces more appealing. Get out there and wire some stuff together and stay warm in your man cave this season. And if you’re not heating with combustibles, take the time to properly weatherstrip your doors and windows. Even if you love the tropics, you don’t want to get the PG&E bill for heating the world.

Featured image by: unsplash-logoSteve Halama


About Will Puckett

A 20 year veteran of the San Francisco Bay Area, Will Puckett is an author, artist, and guide. He enjoys styling CSS, and helping friends move furniture. When not parked in front of his iPad, he rescues, restores and rides bikes. Will has been lucky enough to take long rides on both coasts of the United States, and encourages people to explore the world by bike. He tries to lay in his hammock as much as possible reading and planning his future container home, but does enjoy periodically escaping to skate. And of course ice cream.