Attic water heater & attic exhaust fan. (roof, Lowes, tank)

[nacmd70]

We are not permanent residents of North Carolina yet. Our water heater is in our attic(really scares me). When we are not present I set the temp gauge to the lowest setting. We were back for a few days and not only was the tap water warm but the shower was very comfortable and could be made too hot. I assume this is because of the markedly increased temperatures over the last month. Would wrapping it with insulation be of benefit in the winter and just removing it in the summer?
Second question. Anyone have experience with an attic exhaust fan to lower the attic temp and hopefully decrease the "load" on the AC.
Any input appreciated.

[Barking Spider]

Most newer water heaters do not benefit from an insulation blanket. IN fact, if you read the manual, they tell you NOT to use them.
Hopefully you have a pan with a drain pipe under the water heater in the attic.
The water pipes in the attic should also be insulated.

Most attics I see have either not enough ventilation, or the very minimum the code requires. You can use passive vents or the thermostat controlled power vents. The placement and type of vent is dictated by the type of roof and ventilation you have now.
Some houses have a gable vent on each end of the attic that provide a cross ventilation. Others have soffit and ridge vents that provide a ventilation pattern that is more up and out. Both work fine, it depends on the type of roof you have.
Hip roofs usually don't have enough ridge length to get enough ridge vent area to provide adequate ventilation, so they need power vents.
Houses that are really wide and have gable vents can have air flow issues because of the distance between the gables, so vents are needed in the middle section of the roof.
The short answer is a power vent will probably work OK and get you additional ventilation.

[CyFree]

If your water heater is an older model it is a good idea to insulate the tank (and leave it insulated year round), and the pipes. Insulation will prevent standby heat loss, and the water will need to be reheated less often.
You can then turn down the thermostat. For every 10 degrees you turn down, you can save 3-5% in water heating costs.

I would, however, recommend you consider installing an on-demand tankless water heater, since your current one is located in the attic. This is the time to do it too, because you can take advantage of energy efficiency incentive programs in your area, and there is a Federal Tax Credit for ENERGY STAR (R) qualified tankless water heaters that can be claimed up to December, 2011. In addition, savings of up to 45% in your water heating costs will give you a great return for your investment.

Here's a link to all the incentive programs available in North Carolina

As for the attic, attic exhaust fans will not reduce the load on your A/C at all. They might make things even worse, because when they blow out the hot attic air, replenishing air is sucked straight from the living area. In other words, the air that you are paying to cool your living space, will be cooling the attic instead, and that will make your A/C unit work harder.

Consider a radiant barrier to cool down the attic instead. A radiant barrier is less expensive, doesn't need to run on electricity, and controls attic temperature by reflecting sun heat back to the outside.

To improve the efficiency of your current A/C system consider better attic insulation and proper air sealing, along with air duct, cleaning, sealing and insulation where needed.

A home energy audit would help you detect air leakages, duct leakages and areas where you need more insulation.

[sacredgrooves]

Powered attic fans are a common source of house fires. People rarely visit the attics and may not realize that the bearings have siezed up, and the electricity continues to flow to the unit. The also tend to pull conditioned air from the living space unless you have adequate soffit ventilation and have been found to cost more energy than they save. Most modern houses in NC have ridge vents anyway, and the powered fans are counterproductive with that type of ventilation. Passive roof vents will help though, as will installing radiant barrier or spray foam in the attic. Those are expensive endeavors though.
If you would like to read all about this, plus other energy savings ideas, check out Advanced Energy, an Energy Efficiency Services Firm They are building scientists out of N.C. State University with a wealth of information.