An additional look at ICC’s 2015 mechanical and fuel gas code changes.

A proposed change to the International Fuel Gas Code would prohibit fuel-fired appliances from being located under stairs in engineered residential buildings, such as the Council Tower apartment complex (featured in pme Sept. 2011). Photo by Dan Frisch

In last month’s column, I addressed a number of proposed changes to the International Code Council’s International Plumbing Code. This month, I will continue with a review of the proposed changes to the International Mechanical Code and International Fuel Gas Code.

More than three-quarters of the changes proposed to the mechanical code directly relate to air-moving systems. While I’m not ignoring these changes, I will not be addressing any of them other than the changes to plenums.

Unfortunately, the proposed changes to plenums impact all other systems, including plumbing piping, fuel gas piping and hydronic piping. For the last 30 years, there has been a saying, “What’s a mechanical code hearing without hours of discussion on plenums?”

That will occur again this year. There are 16 proposed changes to the plenum section. A number of changes propose to completely eliminate plenums and require ducts for every air-handling system. When you read the justification for some of the plenum changes, you would be convinced that plenums are the most dangerous components that could ever be added to a building.

While these changes are somewhat crazy, it would make life easier for all of us since we would no longer have to worry about what type of piping material was exposed in a plenum or what type of insulation could be used in a plenum.

Many of the remaining plenum changes relate to what can be exposed in a plenum. Some changes want tighter requirements and additional fire testing of material. Other changes want to expand the allowance of materials, such as plastic water pipe. I always found it strange that certain individuals get so concerned about plastic water pipe. If it does burn through, wouldn’t the water that comes out of the pipe help to put out the fire?

Most of the plenum changes are submitted by those with vested interests. The finest proposed change was submitted by the code action committee. This is a group that studies issues in detail - without any vested interests. When I read the committee’s change to plenums, I can say that I was very impressed. Committee members have addressed all the concerns and have logical, straightforward requirements.

Hydronic piping and boilers

This is the first time in many years that there are a number of proposed changes to the hydronic piping and boiler sections. Many of the changes to the hydronic piping section include material requirements. Two of the changes directly relate to ground-source heat pump loop systems. The current code allows any hydronic material to be used for ground-source heat pump loops. The two proposed changes would restrict the material to plastic pipe.

While it is well-known that polyethylene dominates the piping material for ground-source heat pump loops, there is no technical justification for limiting the material to only plastic pipe. If someone wanted to spend the money to install copper tube, why should the code prohibit its use? Some of the first ground-source heat pump loops were installed in copper and steel. There is no reason to restrict the use of these piping materials.

A part of those same two changes would remove the use of polyethylene from an acceptable hydronic piping material for everything but ground-source heat pump loops. Again, there is no justification provided for removing polyethylene as an acceptable material for other hydronic piping systems. Polyethylene is currently used in many chilled water systems, as well as low-temperature radiant heating systems.

Another change to the hydronic piping section would require a thermal barrier below a snow-melt system. That change perplexed me. With an interest as to why such a change is proposed, you search for the answers in the reason for the change. The reason given for this change was that this was always the intent of the code. My immediate response was: “No, it’s not. Otherwise it would have said that.”

The funny thing about this change is that the thermal barrier below a radiant heating system is designed to save energy. With a snow-melt system, we are just throwing energy outside. After all, isn’t that what the system is doing? Heating the drive or walkway so that snow doesn’t stick? This appears to be a misguided code change.

Fuel gas chatter

The International Fuel Gas Code has the fewest proposed changes of all the codes this cycle. The first proposed code change raises a red flag to those who design engineered residential buildings. The change would prohibit fuel-fired appliances from being located under stairs. The one-line reason for the change reads, “Locating gas appliances under stairs may cause a fire that could trap persons and prevent escape.”

I have been guilty of locating water heaters under stairs in engineered residential buildings. With the lack of space often available, it makes perfect sense to locate an appliance under the stairs.

The proposed change does not provide any data that shows the appliances to be a hazard so that they block the escape route from the building. Furthermore, the International Building Code and International Residential Code require all dwelling units to be sprinklered. If an appliance is located under stairs, that space must also be sprinklered. This change basically is saying that the sprinkler system won’t do its job.

Many of the other changes relate to gas piping installation requirements. There is a proposed change to require a thermal shutoff valve on the gas supply to each appliance. Another proposal would require a gas leak detection system. These topics have been discussed in the past. The question always arises as to how much protection is necessary in the event of a fire.

A perennial favorite is a proposed change to prohibit unvented room heaters in dwelling units. This seems to take up a lot of discussion every cycle. Products that have been targeted specifically are unvented fireplaces, which have become very popular in residential occupancies. Every year, the same data is submitted, just in another format.

If you haven’t downloaded the code changes, I would encourage you to go the ICC website and download them. It should be an interesting week in Dallas (April 29 to May 8). If you are in the area, plan on attending.