Got a few estimates from local HVAC companies and it turns out that my furnace is grossly mismatched to the AC--I don't recall the furnace parameters, but it's twice what they'd recommend for my 1600 st ft house. Only upon performance verification is a certification symbol applied to HVACR products … All Topics Topic Home & Garden Heating & Air Conditioning » Mismatched compressor & air handler = big trouble decycled Posts: 1, Reputation: 1. This may not work as designed, even if it is the same size equipment. The indoor unit is 20 years old, 14 Seer condenser, 10 Seer airhandler. Check the voltage if the blower does not work; a tripped circuit breaker is a common result of mismatched voltage. After all, you can’t run your air conditioner or heater unless you have a way to communicate with it—and that’s the job of the thermostat. Services . I have gotten mixed information with local HVAC guys and need to figure this out. I … Decreased Lifespan The Lennox Air Conditioning system is a part of my heating system which makes it a great combination. Unit has a water leak and low on freon, possibly due to the mismatch with the 1.5 ton unit. According to the Air Conditioning, Heating and Refrigeration Institute, when AC coils are improperly matched, “the efficiency and longevity of these systems are significantly compromised”. So I have 5 ton Lennox gas furnace and air handler which is really too large for my house and just came upon a brand new 3 ton goodman condenser and coil for great deal. For instance, if you choose a high-efficiency air conditioner with a SEER rating above 16 and your furnace has an old blower motor, you are using a mismatched system which will sacrifice some efficiency. 301-799-7200. The indoor unit has a coil number. A system that contains mismatched coils isn’t something that Pedro Portillo, president and lead service technician of ACU Air Heating and Air Conditioning, Conroe, Texas, likes to see. You see, mismatched coils put extra stress on your AC system. Refer to your owner's manual for specific model limits prior to changing power sources. Prior to this, the air handler had been replaced in 2004, and the condenser in 2002. Categories: customer service, FAQs, Furnace draft inducer problems, Instructions, Problems With Answers, troubleshooting, Videos. The AC is 2.5 tons. 5 months ago. If critical zones are served by the AHU system, the system should be capable of meeting the zone loads at the reset SAT. The furnace connection should supply at least 10.5 volts DC and not exceed 14.5 volts DC at the furnace; AC voltage should be between 105 volts and not exceed 135. Typically, to get the maximum efficiency from the AC, you need to upsize the indoor coil by a couple of sizes and install a TXV. So if I understand this correctly, you CAN put a 3 ton coil and condenser on a 5 ton air handler. An air conditioner and furnace is a popular matched system in the Northeast, the Midwest and some places in the South. You Can Search Our Site for More Troubleshooting Problems, Heating, Air Conditioning Parts and Supplies in the Google Seach box below. Reply; Reply with quote; Nov 15th, 2017 5:05 pm #8; Kevinck [OP] Deal … Replacing your Central Air Conditioning or Heat Pump System Split air conditioning and heat pump systems typically consist of two parts: an indoor (coil) unit and an outdoor (condensing) unit. Air Conditioning and Cooling Systems - Mismatched air handler/condensing unit. The problem you find a lot is that the outdoor unit is replaced and the old indoor coil is not. require consideration of these critical zones, as they may prevent the air handling unit (AHU) system from resetting the supply-air temperature (SAT). Built with durable materials and incorporating brilliant technology throughout, Armstrong Air is not only the brand to trust with your home comfort, it’s also the brand more dealers would choose for themselves. Here’s a guide to pinpointing your problem: According to the Air Conditioning, Heating and Refrigeration Institute (AHRI), mismatched systems are at least 30 percent less efficient than matched systems. Decreased system lifespan. The entire HVAC system will suffer if mismatched components are pieced together. But it would seem to be beyond SOP for a Home Inspection. Connected to the inside cooling coil, the compressor pumps refrigerant back and forth, extracting heat and moisture from the indoors. The problem with mismatched HVAC systems is that they are just that…systems. I discuss why I think Mismatched systems are a compromise at best. The vast majority of standard forced air furnaces or furnace/ AC units are controlled by low-voltage thermostat units mounted somewhere in the house, usually in a central location. For an air conditioning or heat pump system to provide proper comfort, efficiency and operation, it is very important for all the components to be matched and sized properly. I do this all the time for Energy Audits and HERS Ratings. Do plan for lowest fluid temperatures: In most hydronic heating systems expansion tank size and air side pressurization is based the assumption that the cold fluid used to fill the system in the temperature range of 45F to 60F. Since 1928, Armstrong Air has been the smart choice for homeowners who expect more from their heating and cooling system. Even modern high-tech wifi or "learning" thermostats operate on principles similar to the classic older dial thermostats. Problems Associated with Mismatched Systems. The Government cannot give to anybody anything that the Government does not first take from somebody else. Thanks for your help. It transfers the heat to the outdoors. I moved into my house in 2005. The "matched" combination usually performs at the lowest rated efficiency -- 13 or 14 SEER. That is fine. Your air conditioner’s indoor and outdoor units must be designed to work together. And they told me that my furnace is sized for a 5 ton AC. If AC does not work with the current wiring, find the yellow wire. Put the white on Y on your Nest thermostat and see if it works. Manual is applicable only to the following models – LNIV2610, LNIV3510, LNIV5010, LNIV6510. If the AC works with the old thermostat, the colors are just mismatched. In the case of mismatched equipment, Call either Mfg and they will tell you if this voids warranty. At some point developers figured out that if a home was a little larger than a 2 ton but not quite a 2 1/2, they could mismatch the unit sizes. But you can troubleshoot your thermostat and furnace before calling a pro. The chemical coolant travels through the coil and then into a device that decreases the chemical’s pressure. Here are some factors to consider, as well as the benefits of avoiding a mismatched furnace and air conditioner. HVAC: Mismatched coils, should I replace AC? Beware the Mismatched Thermostat and Air Conditioner! There is no way a 15 year old system would be 7 SEER. Although it’s possible to mix and match the systems, it’s not recommended, especially if the furnace is over 15 years old. Air-side systems with cooling-only zones (electrical rooms, telecommunications closets, etc.) Spock (rhp) Lv 7. The gas can then absorb heat from the air that travels across the coils. A mismatched system may also break down sooner; What are some signs that I need a new HVAC system? What does an air conditioner do? Repairs and Maintenance; Energy Efficient Installation; 24-Hour Emergency Service; New Installations; VIP Service Plan; Resources. They work and perform best when the components indoors and outdoors match. From there, the chemical coolant becomes a low pressure gas and it temperature hovers just above the point of freezing. The air is very cold but the system stalls from time to time, probably because the condenser coils are too much for the evap coils. New Member : Oct 13, 2009, 12:50 PM Mismatched compressor & air handler = big trouble. And the following issues may arise. When incompatible components are added into the HVAC system, if significantly affects the efficiency and lifespan of the furnace or AC. Parts of an Air Handler . only the three wires? Mismatched Manufacturers is not recommended but may not be wrong. The breaker will trip once every 80 start cycles...happens maybe 3 times a year during the summer time when we use the AC. Points to Ask When Thinking Over Air Conditioning Replacement and Furnace Replacement at the Same Time. I would get the thermostat that is meant to work with the furnace to get the most efficiency out of both. 0 0. Having a working thermostat in your home is critical. It’s a good idea to hire a pro to address any thermostat- or furnace-related problems. it must be compatible with outdoor unit. An under- or over-heated home or an unresponsive thermostat is a common sign of a mismatched thermostat and furnace. FYI the "mismatch" sized unit thing is both not uncommon and not a very large problem. These two parts are specifically designed to work together as a coordinated “team” to provide top performance and maximum efficiency and comfort. Inspection AC report said that main unit is mismatched. They would put a larger air handler inside and the smaller condenser outside. An AHRI-matched system is recorded by AHRI as a properly matched system. LENNOX MINI-SPLIT SYSTEMS SERVICE MANUAL Lennox Mini-Split Service Manual PDF is here if further troubleshooting is needed.. LENNOX SERVICE MANUAL FOR ROOM AIR CONDITIONER (Inverter Split-Type) PDF is here. Get part numbers from both units for when you call. Posted on August 28, 2012 February 25, 2020 by Steve Arnold — 220 Comments … “A system that is properly matched will operate at its fullest efficiency, providing the customer with a more comfortable environment at a lower operating cost,” he said. makes me think this is an a/c only system and your heat source is something else [the RH terminal is usually for heating]. - I had what I thought was a new Goodman 12 seer, 3 ton heat pump full system installed last November. Tag: Heating troubleshooting. I'll try to be as succinct as possible.. Signs of a Mismatch . The Lennox outdoor unit and indoor coil has a 10yr parts, 10yr compressor, 1 … If you thi. Air Conditioner + Furnace Matched Systems. 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