Comments for Mark Robison, P.E.

Comment on Hotel Bath Exhaust Subducts by Henry

Henry — Mon, 09 Jan 2012 13:55:24 +0000

Also, to respond to Mike’s question about the 25% rule of thumb: this is a guideline documented in SMACNA’s “Fire, Smoke and Radiation Damper Installation Guide for HVAC Systems”

Comment on Hotel Bath Exhaust Subducts by Henry

Henry — Mon, 09 Jan 2012 13:47:00 +0000

To respond to Mike’s question (only a little over 2 years too late for his meeting): the code section in the 2006 International Mechanical Code is: 607.5.5 – Exception no. 1.1.

I disagree with Mr. Robison’s assertion that “Since fire smoke dampers are expensive, the code offers an alternative as follows…”

This is not the intent of the code. The motivation of the code is always safety and never money. If you read the commentary version of the code, you will find that this exception is intended to allow exhaust systems to continue exhausting potentially hazardous fumes during a fire emergency. The idea is that in some cases (namely, in the case of laboratory fume hood exhaust) the amount of safety added by allowing the exhaust to continue to run through a sub-duct assembly more than compensates for the amount of safety lost from the absence of a fire damper.

Comment on Hotel Mitsubishi City-Multi VRV Installed at Sheridan Carlsbad Resort & Spa by Paul O'Connor

Paul O'Connor — Fri, 21 Oct 2011 11:12:19 +0000

Mark,

Quite an interesting installation technique.

Given the hotel application and depending on the number of heads, the AG150 master controller is an excellent option for the entire building. With expansion cards, it allows for connection of up to 150 fan coil units throughout the building, to one main colour touch screen.

This is particularly useful in hotels where it enables management at reception to manage each room individually as a patron checks in,adjusting start/stop, temperature etc, without the need for a full blown BMCS system, or indeed waiting for the client to reach his/her hotel room to bring conditions to an acceptable level. This enhances the energy rating of the facility with specific management of AC operating times.

The applications thereafter are numerous for lots of various commercial applications. I have managed at least 15 major installations of this type. Some with 170 + fan coil units.

Additionally, the AG150 can be linked directly to a BMCS for a commercial office space via a BACnet module, with high level link on Cat 6 cable. I find it ideal to mount the AG150 directly onto the face of the Mechanical switchboard, as a monitoring point of all the VRF, without the need to interrogate the BMCS head end during routine maintenance.

Im guessing in this instance, you installed the heat recovery VRF rather than the heat pump system, with the fresh air make up to the unit dependent on whether it be natural (ie. openable windows), or forced (ie. a fully sealed hotel room).

Comment on Trouble Shooting Hotel Hot Water Recirc Systems by Jessie

Jessie — Sat, 10 Sep 2011 01:22:31 +0000

I manage (2) hotels as the Chief Engineer – I am having some opportunities with no cold water on all 5 floors. I played with the balancing valves on the 4ht floor, adjusted the 2 symmons mixing valves temps set at 120 – I have 2 circ pumps running 24/7 the timers have been by passesd why? And how can I begin this process of eliminations I am getting complaints at all hours. Please assist me with good pointers to get this fixed.

Thank you,

Comment on Trouble Shooting Hotel Hot Water Recirc Systems by Chin Joong onn

Chin Joong onn — Mon, 04 Apr 2011 07:25:20 +0000

Dear Sir,
What is the international standard of when you turn on the hot water and within how many second you will get the hot water. We are having 9 sec.
Please advice.
Thanks.
Chin Joong Onn.
Chief Engineer

Comment on Minimum Hotel Bathroom Plumbing Clearance by The Future of Design Master and Revit - Design Master Blog

The Future of Design Master and Revit - Design Master Blog — Fri, 01 Oct 2010 09:55:05 +0000

[...] Resolve Conflicts: This last step is one that might never be automated. Once conflicts are found, you and the other designers will have to work together to find solutions. Done right, it is possible to reduce the minimum ceiling space in a hotel bathroom from 10 inches to 6 inches. [...]

Comment on CPVC vs Copper in Hotels: Is there Still a Double Standard? by TANDU

TANDU — Fri, 01 Oct 2010 07:27:43 +0000

Can we use in a 5 star hotel CPVC pipes for PHE lines? cost is a consideration.

Comment on CPVC vs Copper in Hotels: Is there Still a Double Standard? by S.S.Karikalan

S.S.Karikalan — Fri, 23 Apr 2010 16:07:41 +0000

PE AL PE composite pipes will be un doubtedly the best bet for plumbing. If the installation is properly done and tested the only least problematic and and least failure and also the best available piping material is pe al pe composite pipes only. Many hotels which has used in Chennai more than seven years enjoying trouble free ervice life. Kitec is only a brand name and the failure is reported in the brass fittings.

Comment on Hotel Mitsubishi City-Multi VRV Installed at Sheridan Carlsbad Resort & Spa by Kelly

Kelly — Sat, 20 Feb 2010 13:35:39 +0000

We did a condo that required fresh air, Mitsubshi makes a losnay unit that incorporates into the system quite nicely, although it is large, sometimes hard to find space for it.
Mark, when I went to Mistubishi school, they repeatedly harped about “NO TRAPS” which in some cases is imposible. I noticed between the outdoor units and the roof penetration you have them all traped right out of the box, is this an issue at all?
Very nice looking job, having the challenge currently of trying to correct a dissasterous install (by others) on a three tower, seven story building I really appreciate seeing good work….kudos!

Comment on Trouble Shooting Hotel Hot Water Recirc Systems by Spike

Spike — Wed, 03 Feb 2010 13:25:47 +0000

I have 2 different hotels, however the new 22 floor hotel has been open for a year now and we have had constant problems with the domestic water – cold backing into the hot, hot backing into the cold etc. Obviously the water problems tend to happen during times of lower water use – during higher volume days we tend to keep enough water moving for the system to be happy. We have a two zone system with PRV’s to maintain pressure at each zone then to make matters worse we have mixer valves installed at each sink in every room & to add to this within the shower valves are Pressure balancing valves. Now let me throw one more thing into the line-up here – on the upper floor mechanical room at the domestic hot water boilers are dual Symmons Temp mixer valves for setting the water supply temp (OK hope everyone followed that). What I have found is that the piping when installed was not sufficiently flushed, I am finding metal shavings getting caught in PRV’s, “Y” strainers, mixing valves, shower valves, just everywhere. This is my procedure when I run into the problem:
1) Basement mechanical room – make sure the cold and hot water pumps are pumping close to the same pressure up the tower.
2) Check the different zone PRV’s- make sure the pressures are close to the same, I like to have my cold water slightly higher then the hot (it’s more acceptable to customers to wait a minute for the hot water then to try to figure out why there is no cold water) I like to change the setting on the PRV’s for each zone just so I can make sure they are working – as we are speaking I have 3 prv’s not working that I have to pull today (like normal suspect debris causing the issue).
3) If it’s hot backing up into the cold – I go to the upper floor mechanical room and check the cold water side of the Symmons temp mixers, if the cold water side is hot I Turn the mixer to as cold as it can get and go to the affected floors and run as much water as I can (both hot and cold to flush the problem out – you’ve got to get the hot out of the cold system, then once you’ve got the hot out of the cold readjust your mixers to maintain the correct temp usually 120 degrees.
4) Then try to determine where the problem is- perhaps you found the problem when you check the Basement pumps or the PRV’s that may have had too much differential pressure or not working at all, was it just one zone affected and if so what group of rooms – were the rooms spread out to different risers? Knowing the rooms can tell you if it was a under sink mixer within that riser that could have been causing the problem. You have to isolate where the problem is coming from in order to determine what is causing the problem, THEN you can resolve it. Keep in mind the “Needle in a haystack” scenario if you have a setup like mine – the culprit tends to change each time it happens – other then the primary culprit with is usually a debris problem.

Note to James’s problem above: James I would look at the size of the circ pumps, sounds like they may have been undersized. Now it this is a problem that just started to happen I would consider the age of the circ pumps and that perhaps the impeller has worn or become damaged – or perhaps the wear rings internally have opened up- you might need to rebuild the pumps, are you able to maintain pressure sufficient to get to the upper floors? (Remember it takes 1psi of pressure to climb 2.31 feet of height and that you want to add to this figure to the 40-50 psi that you want coming out of those upper floor fixtures so the guest can have a nice shower). Good luck. If I can be of any assistance you can email me at spikesamuels@yahoo.com