Air Conditioning and Heating Sizing | HVAC Technical

Air Conditioning and Heating Sizing
Air Conditioning and Heating Sizing - It is not uncommon for HVAC estimators or HVAC contractors to use various rudimentary techniques, which are generally referred to as rules of thumb. Some will say on the low end you need 1 ton of cooling for every 500 square feet.

On the high end, you will need 1 ton of cooling for every 700 square feet. These rules of thumb will also generally take into account a basic heat gain calculation for the kitchen and the number of people who will occupy the structure. (more…)

Outside Air Dampers with Energy Recovery | Energy Efficiency

Outside Air Dampers with Energy RecoveryThe dampers straight across are outside air dampers or make-up air coming from an energy recovery unit. According to the mechanical code, commercial buildings require a certain amount of fresh air from the outside to maintain good IAQ for the occupants.

An energy recovery unit allows it to be conditioned before being introduced into the building. Other methods include using enthalpy calculations to open economizer dampers and/or CO2 control of the dampers. (more…)

Ceiling Fan in a Garage | HVAC Airflow

Ceiling Fan in a Garage
Ceiling Fan in a Garage | HVAC Airflow – 
This ceiling fan keeps the air moving in a large garage where repairs are made to heavy machinery. In addition to providing a level of comfort by keeping the air moving in the shop the ceiling fan also helps to keep noxious fumes at higher elevations and moving towards the exhaust fans so the noxious fumes from heavy equipment can be removed from the shop area. (more…)

Infrared Radiant Heating Systems | Garage Heaters

Infrared Radiant Heating Systems | Garage Heaters

Infrared Heating System

Infrared Radiant Heating Systems | Garage Heaters

Infrared Radiant Heating systems provide comfortable heat in larger areas and spaces such as garages, warehouses, and other open spaces where other types of heating systems are not practical or efficient. Infrared radiant heat works through thermal radiation transmitting heat to large objects including floors and walls.

These large objects heat up through thermal radiation and then release that heat to the surrounding air through convection making the open space or open area comfortable for the occupants. (more…)

Grounding and Bonding Electrical Systems | NEC Code

Grounding and Bonding Electrical Systems and the NEC
Grounding and Bonding Electrical Systems | NEC Code - National Electrical Code Article 250 is all about grounding and bonding as represented in this photo where electrical systems are grounded and bonded to the buildings steel structure.

There are many different rules in the NEC (National Electrical Code) pertaining to grounding and bonding because grounding and bonding are important for safety reasons. Electricity will take the path of least resistance so if there is a short in the system the grounding system will be the path for the electricity instead of the motor or load that experiences the short. (more…)

Home Ventilation and Pressure | HVAC Venting

Home Ventilation and Pressure - It is becoming increasingly necessary to have your home checked for home pressurization. Does your home have negative pressure inside of it? Do you have a gas or oil furnace which is inside the home and uses the air in the home for combustion air to fire the furnace or boiler?

Do you have other gas or oil-burning appliances, a fireplace, gas logs, or anything which consumes air inside the home? This does not refer to furnaces that are located in the attic (unless you have a completely sealed attic or the attic has a maximum height of fewer than 30 inches.)

Home Ventilation and Pressure | Appliances and Air Content

These appliances consume air and along with some other air-consuming appliances in your home, the issue of home pressure and home ventilation comes into question especially in this day and age when the drive is on to increase efficiency and reduce energy consumption.

Homes are being built tighter with better insulation, doors, and windows. Less infiltration air is being fed into the modern homes of today so it’s important to give the home a safety check to make sure there is enough air left over for the occupants of the home.

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HVAC Duct Work – Air Handling Unit Duct

HVAC Duct Work - Air Handling Unit Duct - Air Handler Duct WorkHVAC Duct Work delivers the conditioned air to the spaces. The Air Handling Duct channels this conditioned air to spaces where it is needed and then a return duct channels the air back to the air handling unit duct for re-conditioning. The return ductwork has a negative pressure while the supply ductwork has positive pressure.

In commercial systems and tight residential homes, it is necessary to add fresh air to this conditioned air so the air remains fresh and healthy for the occupants of the structure. This is required by the mechanical code and often this air comes through ductwork from the outside. (more…)

HVAC Duct Systems

HVAC Duct Systems - Round Hard Duct WorkHVAC Duct Systems - Ductwork systems channel the air to the spaces where it is needed from the air handler. HVAC duct systems also will pull the air from the space and channels it back to the air handler where it needs to be conditioned. In some commercial applications, the area above the ceiling is considered the return duct. All the return air is channeled back to the air handler through the plenum where it is conditioned in the air handler. Part of the conditioning process is the air being passed through an air filter and then an exchanger like a coil or heat exchanger. (more…)

Heat Pump Thermostats | HVAC Heating and Cooling

Heat Pump ThermostatsHeat Pump Thermostats - To the average person a heat pump thermostat can be a very complicated thermostat compared to the typical thermostat which serves an air conditioning system with gas, electric, or an oil furnace. Of course, the heat pump thermostat typically has more wire terminations than the regular thermostat.

It has more switches to control emergency heat, and some even have lights, which will indicate that the auxiliary heat or emergency heat is functioning. Most heat pump thermostats are two-stage thermostats for the heating mode and a single stage for the cooling mode.

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