Electronic temperature controls began replacing mechanical devices in the late 20th century. Devices called thermistors, which are temperature-sensitive controllers with no moving parts, can be made that provide narrow temperature range control. Thermistors can be connected to control circuits that turn heating or cooling systems on and off, and are used in many digital thermostats.

 

A power conditioner is an electrical device that provides "clean" AC power to sensitive electrical equipment. A typical one for home or office has up to ten or more receptacles or outlets and commonly provides surge protection as well as noise filtering. Many models also provide Ethernet, cable and phone line conditioning.

A thermostat is a device used for temperature control within a home or commercial building. While newer programmable models offer advanced features and increased levels of efficiency, a standard manual thermostat is operated by hand using a built-in dial or switch. Homeowners can set the thermostat at the desired temperature so the heat or air conditioning switches on and off automatically, or simply turn heating and cooling or or off at the flip of a switch.

One of the most operating systems used in the manual thermostat is the bi-metal conductor. These units contain a strip or metal, which can be made from aluminum, tin, steel or some other material depending on the unit. As the room heats up or cools down, the metal reacts to the change in temperature. Once it reaches a specific set point, it sends an electric signal to the furnace or air conditioner to switch on or off. These units tend to be the most affordable, but are also slow to react to temperature changes. While they are effective in the long term, they offer fairly imprecise levels of temperature control.

The term HVAC (heating, ventilation and air conditioning) ductwork describes any system of ductwork and vents used to channel and distribute air in a vehicle or structure. HVAC ductwork systems are used in spaces ranging from automobiles to residential homes to the largest construction sites, but all systems share certain common properties and all provide for the circulation of air. 

Ductwork can be made of a wide variety of materials, depending on the intended site of installation and characteristics of the HVAC system that it is designed to serve. All HVAC ductwork should be appropriately-sized, tightly sealed and securely mounted in order to operate safely and efficiently.

There are a few simple ways for you to eliminate dust mites, and sometimes you may need to use a combination of various approaches to get the effect you’re after. Dust mites need a humidity level in the 50 to 100 percent range in order to thrive properly, so you may want to lower the humidity in your home significantly. This still leaves behind dead mites and their fecal matter, which causes an allergy for some people. To get rid of that stuff, you may need to vacuum and wash everything carefully. Some people also remove their carpets as part of an effort to eliminate dust mites.

Lowering indoor humidity, which is often the primary key to eliminating dust mites, will generally involve reducing the temperature inside of your home. Lowering temperatures tends to make the air dryer, so an air conditioner may be all you need in order to kill dust mites. 

According to some experts, a good temperature to aim for is the 75°F (about 24°C) range. It’s also common for dust mites to die in winter unless you live in a particularly warm climate or keep your house especially humid all the time.

 

There are two main methods for determining the proper duct size for a heating, ventilation, and air conditioning (HVAC) system. The equal friction method determines the pressure loss based on each segment of the ductwork, while the static regain method is based on how static pressure at one duct branch offsets the fiction loss of the section before it. 

A whole house attic fan is a fan that pulls air through the main parts of a house and up into the attic. Though not a standard part of the heating, cooling, and ventilation mechanics typically found in most homes, a whole house attic fan can be a valuable addition to a home, especially in certain climates. Not only can a whole house attic fan help cool a home by creating a continuous draft, most whole house fans are more energy efficient to operate than air conditioners and can achieve the same level of comfort when there is little humidity in the air.

Whole house attic fans started appearing with some regularity in homes built in the late 1950s and early 1960s. They are typically comprised of two parts – a large, belt-driven fan mounted in the attic and a louvered vent mounted beneath it in the ceiling. The best location for a whole house attic fan is in a central hallway of a house. When you open select windows throughout the home, a continuous draft is created by the flow of air pulled through the windows by the fan.

The price of a whole house attic fan will vary and is dependent on size, make and model. Custom installation and models will obviously be more expensive than purchasing standard models from a home improvement store and installing one your self. When purchasing a whole house attic fan, be sure to pay attention to the information on the box or packaging and buy one that is designed for your size home.