Ductwork and High Ceilings | HVAC Duct Work Systems

DuctWork and High CeilingsDuctwork and High Ceilings - I did not see any reference to my question and would appreciate a response as soon as possible, as due to a medical situation, have to make a decision soon. We own an OLD house with 13′ ceilings in a large part of the home and 11″ ceilings in the LV/DR and BR. We are oscillating on where to place the ducts…Floor or ceiling. It appears to be counterproductive to me to put the ductwork in the ceiling since it will have so far to go.

We are looking for the most cost-effective, not upfront cost but operating cost, solution. In addition, we are considering DF heat pumps. The house will need 2 or 3 to be zoned correctly. Please let me know about the duct placement and thank you for your help? (more…)

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…)

Air Handler Water Coil Freeze Stat | Freezing Protection Control

Air Handler Water Coil Freeze Stat - Freezing Protection Control
Air Handler Water Coil Freeze Stat - The HVAC Air Handler Freeze Stat is a low-temperature limit control and it is used mainly in commercial systems in the ductwork on economizers or in air handlers just before any coil especially water coils. It is a safety and protection control to prevent extremely cold air from reaching the hot water or chilled water coils inside the air handler where the air enters from the economizer.

Under ideal control setup if the freeze stat trips the economizer dampers close and the blower fan stops. This prevents coils from freezing. A frozen coil can bust open and will need to be replaced if it freezes. This is the purpose of the freeze stat in HVAC air handler applications which utilize economizers for free cooling and other purposes.
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Chilled Water Pipe Vibration Isolators | HVAC Piping

Chilled Water Pipe Vibration Isolators
Chilled Water Pipe Vibration Isolators - Vibration isolators protect the chilled water piping from receiving vibrations transmitted through the piping when the chillers are running. The vibrations can create problems not only for the chilled water piping but also for the building’s structure. The vibration isolators reduce or eliminate the vibrations that can be transmitted by the chillers. (more…)

DDC Control Module for an Air Handling Unit | HVAC Control

DDC Control Module for an Air Handling UnitDDC Control Module for an Air Handling Unit – This is a direct digital controls control module for an air handler that serves some VAV boxes in office spaces for a Data Center. This DDC control module includes analog and digital inputs and analog and digital outputs to handle all the control functions necessary to control the devices and components on a large commercial air handler. (more…)

Air Conditioner Ductwork Leaks | Leaky Duct Work

Air Conditioner Ductwork Leaks | Leaky Duct Work - A good consideration when replacing the air conditioning system is the ductwork.

Air Conditioner Ductwork Leaks

Red Arrow Shows a Duct Work Leak

Ductwork seems to be the most ignored part of an HVAC system. However, it is a very important consideration in this age of new technology and higher energy-efficient equipment being developed and manufactured. You can have the most energy-efficient engine but if it’s in an old 60 or 70’s model car your efficiency is going to suffer. The same is true with HVAC systems. (more…)

VAV Air Handler | HVAC Zoning

VAV Air Handler and HVAC ZoningVAV Air Handlers are ideal for providing zones in a commercial building. Office space typically has several offices and open areas that need to be conditioned for the comfort of the people working in those areas or offices. By installing VAV boxes and zoning the ductwork from those VAV boxes these areas and offices can be kept comfortable using a VAV air handler system. More on how VAV boxes work. (more…)

Dust Smoke Filter Banks | HVAC Ventilation Systems

Dust Smoke Filter BanksDust Smoke Filter Banks | Indoor Air Quality

Dust Smoke Filter Banks - These filter banks filter the exhaust air from a welding lab where lots of smoke, fumes and related dust ends up going through these smoke filter banks. Specialized filtering systems are commonly used in industrial areas where fumes, smoke, and dust can be hazardous to the health of people working there. (more…)