Rapaire -

You would probably be thinking of ceiling fans, suspended, to bring some of the heat that rises down to useful levels. These can be quite helpful in evening out the temperature, but of course require installation - hanging and often routing wire and installing outlets.

As a test of whether this is going to actually help, you can probably get circulation comparable to a couple of ceiling fans with a portable fan on the floor that you can plug into an existing outlet and aim upward to set up the desired circulation if you use one of the high efficiency ducted fan models like the Vornado in each of your problem spaces. This will give you an indication of whether circulation is really going to help, and/or if the lowered ceiling is really needed.

Metchosin -

If you put 60 Watts into any electrical device in a closed space, you get 60 Watts worth of heat. Whether if comes out of the device as heat, light, or noise, the "heating" is the same. The problem with using a lighting device as a heater is that it's difficult to regulate it so that it's used when needed and not used when it's not needed. With many devices designed specifically for heating, a thermostat is included so that they run only when they should run.

A 60 Watt incandescant bulb puts out less than one Watt of light, while a 14 Watt fluorescent "bulb substitute" produces the same amount of light. If the purpose is to produce light, the fluorescent saves about 75% of the electrical power that would otherwise be used. Usage is highly variable with people's personal habits, but a rule of thumb sometimes used is that 30% of the electrical power one buys is used for lighting, if you're in an "all electric" home. If you have another method of room and water heating, the "lighting" burden can be as much as 60% of your electrical consumption.

A 60 Watt light bulb running for one year (8,766 hours) puts about 565 KWH additional consumption on your electric bill. Of course the rated life for 60 W incandescant bulbs is about 1,500 hours, so you'll use about 6 bulbs per year if you leave them turned on all the time. For your pumphouse heating, the biggest inefficiency comes from the need to have enough instantaneous heating rate for the coldest one or two really cold nights, but most of the time you're using 60 W when 25 or 30 W would be enough, even in winter. A thermostat to turn the "heater" off when it's not needed likely would reduce the energy consumed to about 10% - or less - of what you're using with an unregulated heater on all the time (or at least on all winter).

A small heater, with fan and thermostat, set to as low a temperature as possible, probably would actually pay for itself in fairly short order in your pump house. Most such units run to 900 W - 1,500 W, but a thermostat would allow it to run only when actually necessary. Of course you lose the convenience of being able to look out the back door to see if there's light coming out the cracks to know that it's still working.

The thermal tapes made for wrapping the pipes under your mobile home are a compromise. They generally operate at a fairly low power level, but some incorporate a "thermister" that changes resistance in response to tape temperature and reduces the power level as the tape warms up. Even without the thermister, the change in resistivity¹ as the metal heater wires warm will "regulate" the power level so that you get more current at low temps and somewhat less when the tape/room is warmer.

¹ Your light bulb works somewhat the same. A 60 W bulb at 120 V must have a current of 0.5 Amps, or a "hot" resistance of 240 Ohms. A cold (room temp) 60 W bulb typically has a filament resistance of about 12 to 14 Ohms, meaning that the initial current to start heating up the filament is about 20 Amps, and the "turn on" power level is about 240 W (but ony for a tiny fraction of a second).

Using your light bulb to heat the pump house is a matter of putting in some heat and hoping it's enough. Patching the cracks won't make any real difference, since you'll still leave the light on all winter. If you should decide to use a thermostat control, reducing air leaks is very important if you want to minimize the actual power requirement to keep the shack warm. Most of the heat loss in typical structures is from warm air leaking out and cold air, that must be heated, leaking in to replace it.

While your incandescant light bulbs will contribute heat to warming the house in winter, you're unlikely to change bulbs repeatedly as the seasons change². My recollection of Vancouver Island and vicinity is that the heating season is pretty mild, and if you're using electric heat the "30% for lighting" is probably a fair estimate. Changing from 60 W incandescants to 14 W fluorescents should save you 75% of that 30%, or about 22% of your overall annual electric consumption - if you're a "typical user" (which is somewhat doubtful). If you're using fuel oil or natural gas for water heating, the percentage might double, but of course that's a bigger percent of a much smaller electric bill. I'll note that while fluorescents claim a much longer life than incandescant bulbs, the claims are somewhat exaggerated. They do last longer, but not as much longer as claimed (3 to 4x, but not 10x). In my area, recently, the fluorescent replacements for incandescant bulbs have dropped to about 2x in price, if you get them in bulk from a discounter (Costco in your area?), and do last at least 3x as long as incandescants.

² If you happen to use air conditioning, each extra WH of heat dumped into your house when the air conditioner is running generally requires very roughly 2.5 WH of additional consumption in the AC to pump it out.

John