Aboutjohn t. borgman Expertise I work days, so I can only answer early in the day or later in the evening, I live in Oregon. I have been so good at all the other area's of hvac, I am probably the only hvac guy that does not know oil. ( lol ) I am very well versed in gas, electric and heat pumps and will only answer residential applications. I have been known the past decade or so, by my employers as the guy you send when no one can figure it out. Trouble shooting is my special. I understand the physics behind air flow, refrigerants and electricity. I understand programmable t-stats, zone controls, economizers, fossil fuel kits and the engineering thought process in the wiring and construction of residential equipment
Experience I was lucky enough to start in this field over 25 years ago as an installer, for a company that installed the best duct systems I have ever seen, even to this day. The best ,as far as understanding the way air really flows through a duct system, from the return air to the very last supply register . They also had great pride and the duct work was put in, not only to last 50 years, but to look exceptional. Then as I started doing service work, I was again fortunate that I found a 3 year engineering class being put on be a man that was the educational director for the Entire united states for a society called " the Refrigeration Service Engineering Society " And for the next 3 years I schooled at night and practiced what I learned during the day, a great advantage over schooling and then trying to remember it years later.. Versed in duct design manual J heat gain/loss calculations. Also experience in wine rooms and indoor swimming pool hvac & humidity controls
Publications I have 2 inventions that have gone through the process and been recorded at the National Institute of Standards and Technology from start to finish and thus been invited to national innovation workshops by the dept. of Commerce and the dept. of Energy. They are waste heat recovery devices that N.I.S.T approved as valid and am currently looking for marketing partners to get this product into the hands of consumers and make a BIG difference in Energy savings for every Household and Eatery and take a big bite in the the peak hours power consumption that face our Utilities companies.
Education/Credentials factory training in Lennox ,Rheem, Ruud ,Trane, Tempstar ,Carrier, Day&Night, Payne, Bryant, Coleman, Intertherm, Ultra boilers, Unico, Mitsubishi,Sanyo, Taylor, Nicewonger, . Associates degree in Refrigeration Engineering. Certified with Energy Department, Check-me Program, have N.A.T.E. certifications in gas, a/c & heat pump. Teach and apprentice at every company I work at.
Question QUESTION: We are looking to replace our A/C and furnace. One guy told me that a two-stage A/C is more efficient because it can run at a lower speed and will remove more humidity from the air. He didn't say I *needed* this, but told me the advantages. But someone else told me that a two-stage system will not effectively cool our upstairs because at a lower speed, the air just won't get up there as well. This guy said that I can get a single-stage system that controls humidity (Bryant 165A A/C).
I have a quote for a single-stage non-communicating system, a single-stage communicating system with more humidity control (the Bryant above) and a two-system. I don't like my house over-air conditioned, so I think having lower humidity would help a lot. I'd like the efficiency (and lower noise level?) of a two-stage system, but don't want something that won't work.
So, single-stage or two-stage?
ANSWER: Claire,
Go with the Bryant which is a carrier product. The outdoor high seer unit is so quiet you wont even know it is on unless you walk up to it. But you cannot have it both ways. If you do not want your house cool, then you cannot drastically lower the humidity, but you can remove humidity that way. It is the first thing removed before we lower the SENSIBLE heat which is what we feel on our skin. The more humidity you remove ( LATENT heat ) the more SENSIBLE heat is affected. That is just physics. Unless you have a huge humidity load like a swimming pool, in which case you basically have a mismatched system for removing the water and the sensible heat is not affected much.
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QUESTION: Thanks for your answer, but actually I got a quote for a single-stage Bryant system and a two-stage Bryant system. I also got quotes for single- and two-stage Trane systems.
My main question was whether a single-stage or two-stage system was better for cooling a two-story house. One guy told me the upstairs won't cool properly with a two-stage system because on the lower speed, air won't get upstairs. But I've also read that a two-stage system, which runs lower and longer, is better at keeping the temperature consistent between the upstairs or downstairs.
So which is it? Which is better at cooling both upstairs and downstairs?
Answer Claire,
It really depends on your duct system and that is something that the contractors should be looking at FIRST. If you do not have the proper air flow and volume at any speed to match the btu heat gain/loss of each room and a proper return air system, it will not make a big difference, no matter which system you use.
In our industry we use manual J, a math table of values that equate to the type of insulation, windows infiltration, ect. All of that is calculated and the proper amount of cfm of conditioned air is delivered at a certain velocity, so that each room is balanced. Now, if you have ( and I am sure you don't ) a duct system like this, then the slower stage can work under low load conditions and high speed can handle the top end of the load position.
