Thermostatic Expansion Valves (TEV or TXV), one of the most popular metering devices for residential, high-efficient air conditioning and heat pumps, have performed almost impeccably for decades. Unfortunately, some manufacturers in the past few years have identified batches of valves that have had high superheat issues. Have we just been blind for so long, not realizing these problems existed? Or have these valves really been so reliable for such a long time?
If you think you…Continue
Added by Christopher Morin on July 21, 2014 at 6:30pm — No Comments
For as long as I can remember, the agreed epidemic with ductwork was always undersized return ducts. Although we are far from perfect with duct sizing in New England, I have frequently seen great strides in fixing this issue - particularly with replacement systems. Lets face it, you should just be properly designing the duct system on new installations. Undersized ducts cause great restrictions in airlfow, raising…Continue
Added by Christopher Morin on July 17, 2014 at 5:29pm — No Comments
This list does not represent the entire code, or even all municipalities. Everyone knows those towns that will hit you on every piece of the local code requirements, word for word from the text. But, don't be surprised when code officials, both building and mechanical inspectors, start failing permit inspections for these previously rarely enforced portions of the code! Are you going to wait until enforcement, or lead the industry in doing what the minimum is required by…Continue
Recently, Friedrich has modeled and sold in limited markets their DIY Mini-Split Heat Pump, Breeze. Just a few days ago, they scaled back their rollout in order to meet customer demand by limiting sales to New York and South Florida. I am torn between…
Attention Wrightsoft Users!
Have you ever completed a load calculation and it just seems like it was short of what you had expected? Particularly when you are first starting out with a tool, contractors can make mistakes. After all, we tend to learn "the hard way", right? In an effort to make software work, the companies tend to start with some default values that require adjustment. For instance, most have the duct system in…
Cleaning the condenser coil. This has always been the number one task that Service Technicians avoid at all costs when maintaining residential equipment. Maybe it is the nature of the fast paced business when the weather gets hot? Certainly could not be the lack of water to rinse the coil as there is almost always is a water spigot on either side of the home. I cannot figure out why, and this may be one of the largest aspects of seasonal maintenance that impacts the efficiency of…Continue
1. If you sign today, I will take $X thousand off!
This is a sales tactic often taken by a used car salesman. A Quality HVAC Contractor will price their installation with confidence, after finding a solution to fit the needs of the customer, and correctly sizing such equipment. I have no problem with "ballpark" numbers over the phone, as this can help sift through customers that are not interested in quality, so contractors do not waste time on what tends to be free…
Added by Christopher Morin on February 1, 2014 at 11:00am — No Comments
Vital to the operation of the refrigeration cycle, superheat must be maintained and stable to protect the compressor. We all know that the heart of the system cannot compress liquid (slug) without bad things happening. This would represent low/no superheat. But, did you know high superheat can cause valve and compressor problems as well? No matter the reason for attaching your gauges to the system, you must check the superheat, in the air-conditioning cycle.…Continue
4 or 5 ton systems should be multi-stage...
Added by Christopher Morin on November 10, 2013 at 11:35am — No Comments
There is nothing more frustrating to me than seeing needless deaths, particularly in America. I thought I saw my share chasing down WMD's that were never found in the Middle East. Does it sound that outrageous to put Carbon Monoxide in the same class as these? Think about it: a Colorless, Odorless Gas that poisons it's targets by being inhaled. The only thing a ruthless Dictator is missing is a way to weaponize this. Based on…Continue
Added by Christopher Morin on November 1, 2013 at 6:05pm — No Comments
Seems pretty elementary doesn't it? What should be a simple safety check on fossil fuel burning appliances, particularly for boilers with regards to ease of inspection, often is assumed with complacency or even goes unchecked. I know everyone's maintenance schedule is packing up in the Northeast…Continue
Imagine knowing the refrigerant charge was correct on a Central Heat Pump or A/C without attaching gauges! No, I am not referring to the Lennox "Approach" calculation, which I have found to be very unreliable to predict refrigerant charge, but instead using the simple total capacity calculation with the correct tool.…
An acronym for what is synonymous with all that is bad with the American Pastime, Performance Enhancing Drugs (PED's) have been proven to inflate a ballplayer's performance. Most important in contract years, a player's performance is measured in specific statistics. So, what if there was a pill, or cream, that an HVAC Technician or Salesperson could take to inflate their numbers. Make them perform at the top of their field and get them the highest pay in the industry? Would you take it?…Continue
I remember not all too long ago, yes I am still on what I hope to be the first half of my life, that Central Air-Conditioning was a luxury. Like the radio, then the television; next the telephone, and now the cell phone, Air-conditioning has become a necessity. What was before Air-Conditioning? What did the weather people (yes, politically correct here on Excess Air) say to the elderly before they would recommend "staying inside, out of the heat"?
I remember what I used to do…
The easiest way to show a homeowner how their investment in high-efficient equipment will help their wallet is to use the "Simple Payback" Calculation. This 'tried and true' sales tactic will quickly explain how many years before the additional investment to upgrade is paid off. Of course, there are many features that a high-efficient system provides, like superior levels of comfort, wether it be climate control or just condenser noise just outside their children's bedroom. These…Continue
There are not as many contractors out there as you would expect that are current with the most recent, and always updating, residential building code. Particularly when it comes to the sizing limitations for HVAC equipment, most contractors consider this minimum requirement by law nothing more than a nuisance. There is nothing more frustrating to see in a quality control role than a system that was sold, sized, and installed prior to the start of the system design process. Completing a…Continue
I remember a rash of nuisance service calls rolling in on weekends like this, the snowfall being the key part. It is amazing how well prepared a Heat Pump is for cold weather, with safeties, defrost controls, and supplemental heat (in most). Unfortunately, they do not come with windshield wipers to keep the condensers clear of snow, and snow will decrease the airflow across the condenser to a breaking…Continue