HVAC « Noel's Green (make that SUSTAINABLE) Blog

Dependence on oil has a BIG cost

the common Oil slick

The massive oil spill in the Gulf of Mexico is too big price to pay for our dependency on oil. Now we have to re-evaluate our energy plans. FINALLY. The sustainable approach is to stop drilling and spend more money on energy conserving measures and renewables.
.
.
.
.
.
.

In this months [...]

Better HVAC can save $48 billion/year in the USA

The latest numbers are that US buildings consume $320 billion/year in energy. 2/5 of all the energy used in the US. And about 40% of the energy (costing $120 billion/year) is used in buildings for HVAC.

Some of the 2009 stats HVAC designs that I have incorporated recently into my office [...]

THE LAST ENERGY CRISIS- 1970s and a B.S. Environmental Design

I have a BS ED, which is a science that encompasses the junction between engineering and architecture. My expertise is in buildings and how they work. I focused all my career on design of the built environment and building systems. I was educated in energy conservation, neighborhood [...]

The bottom line! Building commissioning today

I would like to share this 2006 excerpt from the Building Design and Construction magazine white paper on the bottom line of building commissioning.

To put some solid numbers on benefits of commissioning, Evan Mills, PhD, and colleagues at Lawrence Berkeley National Laboratory, Portland Energy Conservation, and Texas A&M University (Energy Systems Laboratory) reviewed published [...]

Demand Controlled Ventilation (DCV)

A recent article in ASHRAE Journal, “An Updated Look at DCV Approaches“, October 2009, page 82-84, covers an important component of building energy: HVAC ventilation control, also called “Demand Controlled Ventilation“. It is an overview of the reasons and logic behind one of the more cost-effective methods for controlling air quality while reducing energy usage.

Outside air – Opening a window
Comfortable and clean indoor breathing has always been associated with fresh air. You simply dilute inside air with conditioned outside air. Its the same as opening a window (albeit with more precision). Scientific observation reinforces the correlation between fresh air and a comfortable indoor breathing environment.

Formal design procedures and requirements for this have been part of the building codes for several generations. ASHRAE Standard 62, “Ventilation for Acceptable Indoor Air Quality (IAQ)”, is usually the basis for these. In summary, ASHRAE 62 describes uses several methods which to determine the required volume of outside air. One common method relies on a “prescribed“ outside air quantity (volume/time) as determined by the maximum anticipated number of occupants. Outside air volumes often have a considerable impact on the HVAC energy load, therefore close attention is paid the precise control.

Controls – What is DCV?
There are several common methods for controlling outside air. The most common is the so-called “Demand Controlled Ventilation” whereby the addition of fresh air is Continue reading Demand Controlled Ventilation (DCV)

Corporate Geothermal is a Renewable Energy tax credit…

Corporate geothermal or (ground-coupled or pond-coupled ) HVAC systems are eligible for tax credits under the same law as renewable energy measures tax credits. Renewable energies (wind and solar) and combined heat-power systems get a 30% tax credit. A new geothermal /geocoupled heat pump investment will garner a 10% tax refund, which [...]

Calculating the tax benefits

While I was thinking about how to calculate the tax benefits of upgrading and changing or upgrading HVAC systems, lighting and hot water heaters, I decided to see if anyone had made a calculator to analyze it already. Sure enough, General Electric had created this EPact calculator

I have not had the time [...]

BIM forces a break with status quo

Change is in the wind. Software and information technology forces a break with the past.

For generations, we engineers depended on drawings. The desktop PC, and software, such as Autocad, changed our dependence into a 2-d CAD.

Stephen Roth wrote in the recent issue of Consulting Specifying Engineers magazine.

HVAC cooling [...]

Building Air Leakage and Air

I just love this subject. Do you know whether your building is sucking or blowing? Did you know that even a new building, built to the usual building methods, will leak air? In a new project, the key is to make allowance for that, and design, build and validate accordingly. On an existing building, it is important to determine how much and where your building blows or sucks, so you can take action, if need be. Windows, doors, and construction joints all have a normal tendency to leak air or allow infiltration. Varying pressures within the building and across each envelope, causes air to move through these openings.

blower door

“Blower door” tests are a key tool for determining how much leakage occurs and in which direction, in (negative pressure) or out (positive pressure).

The major issues surrounding air leakage are indoor air quality, compromised comfort due to drafts or uneven temperatures, and energy usage. A good HVAC designer will account for all of these, and assure that undesirable effects, such as sucking cold or hot-humid in through the building joints is prevented. Likewise, a good architect/builder will account for the behavior of the envelope assembly, air leakage being but one behavior, in his/her design. (You can’t have a 100% tight envelope in practice, it rather more expensive to achieve 0% infiltration, so we plan for it, and plan to blow rather than suck. This rule does NOT apply to “clean rooms”, of course, where 0% infiltration is mandated.)

Blower door testing is a key component of new building commissioning or re-commissioning an existing building. If you know where all the intakes, exhausts, and door openings are, and their size and type, and then the remainder (theoretically) is the “tightness of the building’s construction”.
Continue reading Building Air Leakage and Air

Energy Engineering for your world

Noel Susskind, PE, LEED AP is an experienced mechanical engineer and building energy expert ready to
serve you. Commercial, government, educational and healthcare facilities are a focus.
He will:

Serve as a high level resource on the latest science and art of building, or introduce you to one. Knowledge includes minimizing building energy (carbon) footprint via [...]