Our Blog

Variable Refrigerant Flow Systems


Building owners and operators are continually looking for ways to reduce the energy and cost required to heat and cool their buildings. Responding to this need, many US and overseas manufacturers are now manufacturing and selling Variable Refrigerant Flow systems (VRF).
These systems are being marketed as a more efficient and flexible alternative to traditional split DX, packaged rooftop and chilled water systems. Benefits are stated to include:

  1. Higher energy efficiency Simultaneous heating and cooling More flexible zoning
  2. Quiet operation
  3. No duct work
  4. Simplicity

However, these newer systems may not necessarily be right for every building or application. Things to consider before purchasing and installing a VRF system include:

  1. Not all VRF systems provide simultaneous heating and cooling.
  2. First cost can be higher, especially for heat recovery systems that provide simultaneous        heating and cooling.
  3. Minimizing or eliminating duct work may not be possible in larger rooms / areas.
  4. Separate 100% outside air systems will likely be required to meet current building and energy codes. Benefits of minimizing duct work are offset by the need to have a fully ducted 100% outside air system.
  5. Maintenance requires more knowledge than split DX and simpler packaged roof top units.
  6. Energy savings in large part can be due to capacity modulation and zoning, which may not be as applicable to all building operations.

If you are considering installing a VRF system in your new building, or replacing your existing system with a VRF system, give us a call. We can help you confirm that the decision is right for your building

Mark Fratto, P.E., LEED AP BD+C

Humidity Control

During several recent conversations, we realized that many building owners, operators and design professionals do not fully understand how relative humidity levels are controlled in a building.
For example, many of the people that we talk to think that humidifiers can control the humidity level by both removing moisture from the air and adding moisture to the air.  In reality, it does not have the ability to lower the humidity level in a building; a humidifier can only add moisture to the air.
If you have an existing facility or are designing / building a facility where the control of humidity levels is important, please give us a call.  We would welcome the opportunity to discuss what type of system(s) would best suit your needs.

CMS Adopts the 2012 Life Safety Code

As you know, CMS finally adopted the 2012 Life Safety Code for Hospitals and Outpatient Surgery Centers as of July 5th, 2016.

What does that mean for those of us in Texas? Well, any Hospital or ASC project submitted on or after July 5th, 2016 and receiving Medicare funding will now be reviewed under the 2012 Life Safety Code. However, if the Hospital or ASC is not receiving Medicare funding, it will be reviewed under the 2003 Life Safety Code.

All other facility types including Dialysis Centers, Free Standing Emergency Medical Care Facilities and Special Care Facilities, will continue to be reviewed under the 2003 Life Safety Code.

The 2012 Life Safety Code references other updated codes and standards that will impact the design of your mechanical and electrical systems. If you have any questions concerning the new codes, please give us a call. We are looking forward to working though this together.

What is Arc Flash

In conversations about electrical systems, you may have heard of Arc Flash but what exactly is it?

The electrical panels and switch-gear in your facility have access to a tremendous amount of energy from the power company. If one of these panels fails or if maintenance / service personnel make a mistake and cause a failure, all of this energy will rush into the equipment with catastrophic results. This failure will result in the release of a significant amount of heat and light.

During a failure, temperatures can reach up to 35,000 degrees. When you consider that the human body experiences Third-Degree burns and cell death at 150 degrees after only 2 seconds of exposure, you can see why anyone in the room is in grave danger.

This heat can cause the inside components of the electrical panels to expand up to 67,000 times in volume. This expansion results in violent explosions sending shrapnel over 700 miles per hour into the room.

Couple this with light damage to the eyes, hearing loss, etc. and you can understand why this is a serious concern and why OSHA is focusing more on Arc Flash every day.

Fratto Engineering has years of experience in Arc Flash analysis and labeling equipment most vulnerable.

If you would like more information on Arc Flash and how to protect your facility, please give us a call at 817-461-2337.


We hope to see you soon at any of the conferences listed to the left of the article.

Mark Fratto, P.E., LEED AP BD+C

Forecasting The New Year

Dear Client

We are pleased to share with you, Mark Fratto's featured article in January 2014's Construction News Dallas/Fort Worth.  Mark was asked: What is your forecast for the AEC industry in 2014? 

Fratto Engineering, Inc. is excited about our performance in 2013.  We finished the year exceeding our revenue projections and meeting profit expectations.  We completed a near record number of projects and added eight new clients.

Our performance is the result of a conservative management philosophy developed to accommodate the economic headwinds of 2013.  We feel that many of these issues will persist through 2014 and therefore plan to continue our conservative approach to ensure that we provide quality design services for our valued clients.

Many forecasts are optimistic for construction growth in 2014 which is promising for the Architectural and Engineering community.  However, as part of our conservative approach we won't be taking this for granted and will continue to keep our finger on the pulse of the economy. Forecasts for Institutional Building construction are encouraging, predicting an increase from 2% to 6% in 2014 with Healthcare flat to 7%.   We will be monitoring this closely as these forecasts can be revised downward; 2013 forecasts were cut by over 50% midway through the year.

Issues impacting design and construction that we are concerned about include GDP, growing government debt, consumer spending, residential housing market, Architectural Billings Index and the Affordable Care Act.

GDP growth overall continues to be of concern.  However, it is encouraging to see that 3rd quarter GDP was revised up to 4.1% lifting the average up from 2.5% for the first two quarters.  Perhaps lower forecasts for the 4th quarter will also be upwardly revised.  If the economy remains sluggish, it will limit the growth of non-residential design and construction.  According to the NFIB, owner optimism is in record low territory, having only been this low less than 10 times in 40 years.  Record high numbers of owners feel that this is a bad time to expand and nearly 70% are not interested in borrowing money.

Consumer spending accounts for 70% of the general economy.  It is reported that consumer spending only grew by 1.4% in the third quarter of 2013, the slowest since 2009.  The majority of consumer spending (about 70%) is in the services industry which only grew by 1.2%.  In addition, consumer confidence declined sharply in October and again in November.

The residential housing market is also a significant driver of the economy and it is unclear if the impending Dodd Frank regulations will have an overall positive or negative impact on this market.  In Texas we have been fortunate that the housing market has been impacted less than the rest of the country.  While housing prices have been on the rise, it will take a few more years for municipalities to realize an increase in tax revenue.

The Architectural Billing Index measures billing relative to the prior month.  After a quarter of marginal increases in billing, the index is again turning negative with November logging an overall decrease with a larger decrease for the Institutional market.

As the Affordable Care Act unfolds it continues to create uncertainty for business owners and for the Healthcare market.  This uncertainty is driving a volatile and limited construction market while providers develop and implement new business models.

We are very fortunate to be located in Texas.  The Texas economy continues to grow at double the national average and the population is expanding.  Couple that with low interest rates, a business friendly environment, etc. and we are excited about meeting the challenges of 2014 and expect results similar to last year.

Mark Fratto, P.E., LEED AP BD+C

Legionella and Domestic Hot Water Systems

Dear Client,

Many of our clients do not realize that Legionella can live very comfortably
in warm water, up to about 122 degrees.  This means that it likes the
building's domestic hot water system.   We have visited several facilities
recently including medical facilities that have chosen to operate their
water heaters at 110 degrees, providing a potential breeding ground for
Legionella.  Building management and operators state that they want to save
energy or that they do not want to run higher temperatures that require a
mixing valve to provide code required temperatures to sinks, etc.

While we understand that budgets for operation and maintenance are under
pressure, we do not feel that this is an area that can be compromised.
Between 8,000 and 18,000 people are hospitalized each year from Legionella
with a fatality rate of 5% to 30%.

We highly recommend operating your domestic hot water system at 140 degrees
and using a quality mixing valve to reduce temperatures to a code required
level for use in your building.  In addition, during any renovation of your
facility, make sure that the contractor does not leave dead end or abandoned
piping in place that can result in stagnant water in the piping system.

If you have any questions regarding the design of your system or the quality
of your mixing valves, please give us a call.  We can help you evaluate your
systems deficiencies and design the appropriate solutions.

Sincerely Mark Fratto, P.E., LEED AP BD+C


Air Conditioning and Heating Efficiency

Dear Client,

With another hot Texas summer on its way, many are thinking about opportunities to make older air conditioning systems operate more efficiently. 

One would think that decreasing the outside air would improve the systems performance.  Actually, we would caution not to reduce the amount of outside air being drawn into the air conditioning system.  By decreasing the outside air, the exhaust system in the building will still be pulling in the same amount of outside air.   Instead of the hot outside air coming in through the air conditioning system and being cooled first, it will come in through the doors, the windows, and any other openings, and not be cooled at all.  Often, this unconditioned air being drawn into the building will cause the opposite effect resulting in higher temperatures and humidity levels in the space.

If you have any questions about your system design or operation, please give us a call.   We can help you evaluate your system's deficiencies and design the appropriate solutions.


Mark Fratto, P.E., LEED AP BD+C


Arc Fault Nuisance Tripping

Dear Client,

Our recent experience with Senior Living facilities has shown that the nuisance tripping of arc fault circuit breakers is an ongoing problem for tenants and building personnel. We wanted to share this article with you and hope that you find it helpful when considering the design of your next Senior Living facility or other building types containing dwelling units.

Mark Fratto, P.E., LEED AP


NFPA 70 (the National Electrical Code) requires that dwelling units have arc fault circuit breakers in all areas except the Kitchen, Toilet and Garage. These breakers are not the ground fault breakers that we are all used to. Arc fault breakers are designed to detect electrical arcs in the wiring system served by the breaker. If an arc is sensed, the breaker will trip. The intent is to reduce the number of fires caused by faulty wiring.

Unfortunately, everyday household equipment and appliances create arcs or conditions that look like arcs to these breakers. This includes vacuum cleaners, commonplace electronics like televisions, fluorescent lighting, etc. 

The manufacturers of arc fault breakers are continuing to update their designs to accommodate the more troublesome equipment and appliances. However, our clients continue to have problems with nuisance tripping.

Until arc fault breaker design improves, this can be minimized by using RFI/EMI filters on household electronics and training the tenant, maintenance personnel and custodial staff to use receptacles that are not protected by arc fault breakers when possible. For example, use a receptacle in the Kitchen or Toilet when vacuuming the unit or using small hand tools during maintenance.

We recommend that you have conversations with your client early in the design process and help them understand that unfortunately these breakers are required by code and they will experience some level of nuisance tripping. Follow this with a discussion of what their staff and tenants can do to reduce the number of problems.

For more information regarding this issue, please contact us at (817) 461-2337.

Important News on NFPA Requirements

Dear Client,

At the 2011 ASHE Conference, we gained some very interesting and important information regarding the National Electrical Code requirements for healthcare facilities. We wanted to share this with you and hope you find the article below helpful when considering the design of your next healthcare project.

Mark Fratto, P.E., LEED AP


NFPA 70 (the National Electrical Code) requires that the electrical distribution system in a healthcare facility be coordinated. In other words, the circuit breaker or fuse closest to the load should interrupt power to a failed device instead of a circuit breaker or fuse that would take an entire electrical panel or part of the hospital off line. Obviously this makes sense, especially in a healthcare facility. However, the code leaves room for interpretation on the parameters associated with the coordination analysis.

Some of you may have experienced local authorities interpreting the National Electrical Code to require system coordination at 0.01 seconds in lieu of the 0.1 second standard that has existed for some time.

The 0.01 second requirement requires a more complex and more expensive electrical system with larger equipment. This has resulted in higher construction costs and larger electrical rooms. In addition, it can increase the incident arc flash energy which increases maintenance costs. For these and other reasons, many states have clarified the code to only require the standard 0.1 second coordination. However, at this time, Texas has not issued that clarification and is leaving the interpretation up to local electrical inspectors.

During the July 2011 ASHE Conference in Seattle, we were informed that the NFPA 99 committee has reviewed this issue at length and the 2012 NFPA 99 will make it clear that systems can be designed for 0.1 second coordination.

For now, we would recommend that you discuss this issue with the local electrical inspector prior to starting the design of any healthcare project.

For more information regarding this issue, please contact us at (817) 461-2337.

Are You Ready For An Emergency Power Outage in Your Hospital?

Dear Client,

Recent winter weather has drawn increased attention to a less talked about power problem. With a little planning, hospital staff can smoothly transition through the loss of power; both normal and emergency. We wanted to share the information below with you regarding these types of power outages.

Mark Fratto, P.E., LEED AP


In February of last year, several hospitals in Dallas/Fort Worth lost power during the snow and ice storms. For many, this was unexpected.

In this case, the utility power failed and fortunately hospital emergency generators came on line to provide limited power to critical care areas. While this creates an emergency condition for the medical staff and their patients, there is power available and most facilities have plans to function adequately on limited emergency power.

However, power outages are NOT limited to a loss of normal utility power. While less frequent, there are internal electrical system failures that can and do cause a loss of power to the emergency (red) receptacles and lighting circuits. In some hospitals, areas like surgery and ICU have a limited number of normal (white) receptacles. Some facilities have no white receptacles or normal lighting.

Many hospitals and their medical staff are not prepared for a loss of power to their red receptacles and do not have a plan in place to continue general and critical patient care with limited to no lighting and power from only a limited number of white receptacles.

For patient safety and an effective staff response, Fratto Engineering, Inc. encourages facilities to educate their medical staff about the possiblity of a loss of power to the red receptacles and lighting circuits. Training should be provided so that the staff understands how to provide ongoing care with a limited number of white receptacles and limited lighting.

For more information regarding this issue, please contact us at (817) 461-2337.