More blog posts about heating and air conditioning: •The coils on my heat pump are covered with ice on cold mornings. What’s wrong with it? •What is an HVAC system? •My air conditioner won’t turn on. •What size air conditioner is right for my mobile home? •What is a “ton” of air conditioning? •Why are some rooms colder or warmer than others? •What is the difference between the “ON” and “AUTO” settings on my thermostat? •The coolant line to the outside unit of my air conditioner is frozen. •What does an ultraviolet air treatment system do? •What is the minimum SEER rating for a new air conditioner? •What does “AUX HEAT” and “EM HEAT” mean on my thermostat? •What does the “AFUE” rating of a furnace mean? •How much life is left in that air conditioner? •What is a geothermal heat pump? •Why is there mold around the air conditioning ducts? •What does the MERV rating number on an air conditioner filter mean?

•What is wrong with an air conditioner when the air flow out of the vents is low? •How much will it cost to replace my old air conditioning system? •What is the difference between the SEER and EER rating of an air conditioner? •Is it alright to close the air conditioning vents in unused rooms? •What is the difference between a heat pump and a cooling air conditioner? •What is the right MERV number for my air conditioning filter? •My air conditioner outside unit (condenser) won’t start and is making a humming noise. •What is an air conditioning heat recovery system? •What is the average lifespan of an air conditioner? •When should I switch the thermostat to “EMERGENCY HEAT” for my heat pump air conditioner? •Why does the air conditioner condensate drain line need a trap in it? •Should I remove an old whole house fan or keep it? •What is a jump duct? •My air conditioner won’t turn on What’s wrong?

•Is it acceptable for an air conditioning condensate drain line to terminate under the house? •What is the purpose of the vent grille over the bedroom door? •Should I have a return air vent in the master bedroom? •Will closing doors reduce my heating and cooling costs? •How much will I save on my utility bill if I get a new higher SEER air conditioner? •Why is there a wall switch next to the furnace or indoor unit of the air conditioner in the garage?cost of 4 ton trane ac unit •What are the most common problems with wall/window air conditioners?fujitsu ceiling mounted air conditioning units •Which one is better for a home heating system: electric or natural gas?charging an ac unit and r22

•Why does an air conditioner condenser need to be level? •Why is it bad to have a clothes dryer vent near an air conditioning condenser (outdoor unit)? •When does the ban on R-22 air conditioning refrigerant take effect? •How can I tell if an air conditioner uses R-22 or R-410A refrigerant? •Why is my air conditioner not cooling enough? •What is a return air plenum for a furnace or air conditioning system? •When is an auxiliary drain pan required under an air conditioner indoor unit (air handler)? A blog with answers to your questions about HOME INSPECTION and HOME MAINTENANCE GO TO BLOG INDEX Exterior Walls & Structures Heating & Air Conditioning Click Below to Link to Collections of Blog Posts by Subject Mold, Lead, & Other Contaminants Older & Historic Houses “Should I Buy A” Termites, Wood Rot & Pests Top 10 Most Popular Welcome to our blog! We want you to be an informed homebuyer, and each blog post is a question that we have answered for our friends and customers over the years.

Hope they help you make a good choice for your next home. As the SEER number increases, the energy usage for the same amount of cooling decreases proportionately. This means that a 12 SEER unit will cool your home using half the energy of a 6 SEER, and a new 13 SEER system is about 30% more efficient than a 10 SEER from the early 1990s. Two mandates by the U.S. Department of Energy have pushed minimum SEER ratings upward. Air conditioning units manufactured in1992 and later were required to have a minimum 10 SEER, and the minimum was reset again to 13 SEER in 2006. Today manufacturers offer a 15 SEER for about 20% more than a 13 SEER base model, and up to 20 and above is also available. While the chart above outlines average SEER ratings for each era of air conditioning production, if you want to know the exact SEER of your air conditioning system, go to our blog “How can I find out the SEER of my air conditioner?” While we hope you find this series of articles about home inspection helpful, they should not be considered an alternative to an actual home inspection by a local inspector.

Also, construction standards vary in different parts of the country and it is possible that important issues related to your area may not be covered here. ©2015 - McGarry and Madsen Inspection. TRANE 4TWA3048A4000AA 4 TON AIR CONDITIONER HEAT PUMP R-410A 3-PHASE 13 SEER 0.0 out of 5 stars Product Warranty: For warranty information about this product, please click here We provide useful tips and information for homeowners, facility managers and contractors looking to improve their current HVAC system. Since the minimum efficiency regulation changed to 13 SEER in January 2006, most OEM systems now incorporate a thermostatic expansion valve (TXV) style metering device as the standard for air conditioning systems. It is now extremely important for the HVAC technician to understand the design and operation of this type of valve. The thermostatic expansion valve (TXV) is a precision device, which is designed to regulate the rate at which liquid refrigerant flows into the evaporator.

This controlled flow is necessary to maximize the efficiency of the evaporator while preventing excess liquid refrigerant from returning to the compressor (floodback). One of the design features of the TXV is to separate the high pressure and low pressure sides of an air conditioning system. Liquid refrigerant enters the valve under high pressure via the system’s liquid line, but its pressure is reduced when the TXV limits the amount of this liquid refrigerant entering the evaporator. The TXV – What It Does Do The thermostatic expansion valve controls one thing only:  the rate of flow of liquid refrigerant into the evaporator. Contrary to what you may have heard, the TXV is designed to control: Trying to use the TXV to control any of these system variables will lead to poor system performance – and possible compressor failure. How the TXV Controls the System As the thermostatic expansion valve regulates the rate at which liquid refrigerant flows into the evaporator, it maintains a proper supply of refrigerant by matching this flow rate against how quickly the refrigerant evaporates (boils off) in the evaporator coil.

To do this, the TXV responds to two variables: the temperature of the refrigerant vapor as it leaves the evaporator (P1) and the pressure in the evaporator itself (P2). It does this by using a movable valve pin against the spring pressure (P3) to precisely control the flow of liquid refrigerant into the evaporator (P4): TXV Pressure Balance Equation P1 = Bulb Pressure (Opening Force) P2 = Evaporator Pressure (Closing Force) P3 = Superheat Spring Pressure (Closing Force) P4 = Liquid Pressure (Opening Force) Energy Transfer in the TXV Here is a closer view of the TXV in operation. The flow of the liquid refrigerant is restricted by the valve pin. As the flow is restricted, several things happen: The pressure on the liquid refrigerant drops A small amount of the liquid refrigerant is converted to gas, in response to the drop in pressure This “flash gas” represents a high degree of energy transfer, as the sensible heat of the refrigerant is converted to latent heat