Air Handling Unit Components 2 | HVAC Forced Air Systems

by | Air Handlers | 0 comments

Air Handling Unit Components 2: Heat - There are many different types and arrangements of heating systems for air handling units and these types of heating systems and arrangements of heating systems vary from commercial to residential. Some air handling units do not have any heat source inside them at all but have remote heat for zoning. The air handling unit provides the airflow and the remote heaters provide heat for zoning.

Sometimes the air handling unit is a VAV air handling unit and other times it is just to provide air for a duct heater whether the duct heater is gas-fired or electric. For air handling units which some have heating systems inside the five main ways of providing heat for air handling units are:

Air Conditioner Squirrel Cage Blower | HVAC Air Flow

by | Air Conditioning | 0 comments

Air Conditioner Squirrel Cage Blower | HVAC blower motors move the air through the system. The blower motor is sized based on the amount of air flow necessary for the system. This blower motor is the supply fan for the supply air in a large commercial York AHU. An AC and heating forced air system is sized based on load. The load factors include heat loss and heat gain, number of people in the building, types of rooms served, factoring in heat produced by equipment such as computers and other heat producing equipment. (more…)

Grounding and Bonding Electrical Systems | NEC Code

by | Technical Reference | 0 comments

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…)

Variable Air Volume Systems – Commercial HVAC

by | Commercial HVAC | 1 comment

Variable Air Volume Systems - Variable Air Volume (VAV) systems are the best way to zone especially in large buildings. A VAV system with the proper controls and setup will help the building owner realize large savings in energy usage. There are many VAV systems out there set up in different ways. The most common set-up (for DDC) is, of course, usually the cheapest to install.

They have an air handler (DX or Chilled Water) which supplies the VAV Boxes with fixed pressure and temperature of the conditioned air. The VAV Boxes have electric reheat which will heat the air if that particular zone calls for heat (it is not uncommon to also find VAV boxes that have hot water reheat although this usually costs more to install but can save in energy costs). More on how VAV boxes work.

(more…)

Helping Your Air Conditioner – Beating the Heat

by | Air Conditioning | 0 comments

Helping Your Air Conditioner - Beating the Heat - The new house you just bought is not so cool and the air conditioner seems to run all the time. You begin to worry that maybe something is wrong with the air conditioner. You tolerate it for a while until your spouse broaches the subject a few hours later. Both of you discuss the matter and come to the conclusion that something is wrong with the air conditioner. (more…)