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 My house currently has 8 (13.75" x 7.75") return air ducts, 4 each on the first and second floor. My furnished basement has no return air duct, but 2 supply air ducts.
My central air condition installer is recommending a 4-ton, 2-stage, 17 SEER high efficiency air conditioner. With the government rebate incentive, it is about $200 more than a 3.5-ton, 13 SEER high efficiency air conditioner that we would otherwise picked. My previous 15 years old now broken air conditioner is 3.5-ton.
The installer recommends adding a return air duct with the opening (10") close (about 2 to 3 feet above) to the "return" air filter. This return air duct will be piped (about 2 feet) to the gypsum wall partitioning the furnace from the rest of the basement.
My question is, wouldn't this new return air duct being so close to the blower, turns into a giant air sucking opening and renders the first and second floor return air ducts useless? Please advise.
Thank you.
Answer Kim,
First, how did your old equipment do before it failed? Second if you increase the tonnage you increase the cfm from the air handler and if your whole duct system return and supply are not sized for it, it will not only not reach those efficiencies, but, not cool your home as well. Was there a problem with temperature control in the basement? I recommend that the company that wants to increase the size show you why and how. In our industry we use a standardized calculation chart called manual J. This calculated the btu heat gain/loss for each room and the amount of air delivered to match it. It also calculates the amount of air that can pass through a duct system at set static pressures.
And unless you have having issues with the basement I would only recommend that you put a flow through grill in the door or something to let the air return easily to the upper floors.
