How To Look At A House

McGarry and Madsen's home inspection blog for buyers of  

site-built, mobile/manufactured and modular homes


Tuesday, May 8, 2018

Here’s links to a collection of our blog posts about HEATING AND AIR CONDITIONING:

Is the energy efficiency of the furnace part of the SEER rating of a central air conditioning system?

Why is the base of the gas flue at the roof red? 

How do I understand the air conditioner or heat pump condenser label (data plate)?

Why does the "AUX HEAT" (auxiliary heat) light keep coming on at my thermostat, even when it's not that cold outside?

What is the requirement for a service receptacle outlet for heating, air conditioning, and refrigeration (HACR) equipment?

Does an old air conditioner use more electricity as it ages? 

Where is the air filter for my central air conditioner and furnace? I can’t find it?

Can I convert a heat pump or air conditioner from R-22 refrigerant to R-410A, or switch R-410A to R-22? 

How can I tell whether the condenser (outdoor unit) is an air conditioner or heat pump?

What is the required clearance for access and working space in front of a furnace or air handler?

 What is a PTAC unit?

What is the difference between an inverter heat pump air conditioner and a conventional one? 

What is the minimum slope of a flue connector for a gas furnace or water heater? 

Will installing a special ultraviolet (UV) light in the air conditioning system kill mold? 

How did homes stay cool in Florida before air conditioning? 

What is the small pipe sticking out of the eaves/soffit under the roof overhang? 

Can I run a window air conditioner on a portable generator?

How much cheaper is it to heat a house with a heat pump versus an electric furnace or baseboard heater? 

What is causing the outdoor unit (condenser) of my air conditioner to shake? 

When is it acceptable to use indoor air as combustion air for a furnace? 

How can I find out the size of my air conditioner? 

• What does a "heat pipe" do in an air conditioning air handler?

Why has the thermostat screen gone blank? 

Why can't I use my home's central air conditioning system to cool the garage? 

Does the condenser (outdoor unit) SEER rating determine the SEER of an air conditioning system? 

Why is my bathroom vent fan not exhausting enough air?

What is the minimum height of a ceiling fan above the floor? 

When should I switch the thermostat to EMERGENCY HEAT for my heat pump air conditioner?

What is a FanRecycler and AirCycler? 

What is a ductless mini-split air conditioner? 

Is a furnace allowed in a bedroom, bathroom, or an adjoining closet?

Does a half bathroom (no shower or tub) require an exhaust fan?

What are the Florida Building Code Energy Conservation Code requirements for installing an air handler in the attic? 

Why does it take so long to cool a house when an air conditioner has been off for a while? 

Why is using a stud cavity or joist space as a return air duct a bad idea? 

What is a return air plenum for a furnace or air conditioning system?

Why is my air conditioner not cooling enough? 

How can I tell if an air conditioner uses R-22 or R-410A refrigerant?

Why do the lights dim when the air conditioner starts up?  

When does the ban on R-22 air conditioning refrigerant take effect?  

Can the return air be in the same room as the gas furnace?

What color should the flame be in a natural gas furnace?

Why is it bad to have a clothes dryer vent near an air conditioning condenser (outdoor unit)?  

Why does an air conditioner condenser unit need to be level?

How can checking the fireplace damper reduce energy bills year-round? 

Which one is better for a home heating system: electric or natural gas?

How can I fix rooms that are too warm or too cold in my mobile home?

What are the ventilation requirements for bathrooms and kitchens in mobile homes?

What are the most common problems with wall/window air conditioners?  

Why is there a wall switch next to the furnace or indoor unit of the air conditioner in the garage?

How much will I save on my utility bill if I get a new higher SEER air conditioner? 

Will closing doors reduce my heating and cooling costs?

Should I have a return air vent in the master bedroom?  

What is the purpose of the vent grille over the bedroom door?

What is a jump duct? 

Is it acceptable for an air conditioning condensate drain line to terminate under the house?

Should I remove an old whole house fan or keep it? 

What is the SEER of my old air conditioner?

How can I find out the SEER of my air conditioner? 

What is the best air conditioner for a mobile home?

What size air conditioner is right for my mobile home? 

Why does the air conditioner condensate drain line need a trap in it?

What is the average lifespan of an air conditioner? 

What does the HSPF of a heat pump system mean?

What is an air conditioning heat recovery system? 

Can a bathroom exhaust fan dump air (discharge/terminate) in the attic?

What are the requirements for bathroom ventilation?  

My air conditioner outside unit (condenser) won't start and is making a humming noise. What's wrong?

Should I move my air conditioner into the attic?  

What is the right MERV number for my air conditioning filter?

Why is my air conditioner running constantly? 

Is it alright to close the air conditioning vents in unused rooms?

What is the "temperature split" of an air conditioning system? 

What is a "ton" of air conditioning?

What is the difference between the SEER and EER rating of an air conditioner?

What is a TX valve or TXV for an air conditioner or heat pump system?

How does a hydronic heating system work? 

What is the minimum SEER rating for a new air conditioner?

What is the difference between a heat pump and a cooling air conditioner? 

My air conditioner won't come on after changing the air filter. What's wrong?

What is a geothermal heat pump?

What is wrong with an air conditioner when the air flow out of the vents is low?

Why are some rooms colder or warmer than others?

Will a house without air conditioning pass a 4 point inspection?  

Why is there mold around the air conditioning vents?

What does an ultraviolet air treatment system do? 

What is an air conditioner for a mobile home called?

The coolant line to the outside unit of my air conditioner is frozen. What's wrong? 

What does "AUX HEAT" and "EM HEAT" on my thermostat mean?

My air conditioner won't turn on. What's wrong? 

What is the difference between the "ON" and "AUTO" settings on my thermostat?

What does the “SEER” rating of an air conditioner mean? 

Is it cost-effective to replace an older, low-efficiency air conditioner system with a new high-SEER system?

• What does the MERV rating number on an air conditioner filter mean? 

What does the "AFUE" rating of a furnace mean?

How can I prevent mold in my Florida winter home when I'm gone for the summer? 

• How can I check to see if my bathroom exhaust fan is actually working and moving air? 

• My bathroom is stinky and humid even though it has an exhaust fan. What can I do to fix it?

Is pipe insulation flammable? 

• Can the disconnect box be mounted directly on a heat pump or air conditioning condenser? 

• What is a Durozone dial-type switch used for? 

• How do I set a humidistat in Florida? 

• Why is there an air conditioning vent (register) outside on the ceiling of the porch?

• When is an auxiliary drain pan required under an air conditioner indoor unit air handler? 

• What is the minimum SEER that HUD requires for an air conditioner or heat pump for a mobile/manufactured home? 

• When did the building code begin requiring bathroom vent fans to discharge to the exterior (not the attic or crawl space)?  

• What is the canister thing about size of a small soda can on a refrigerant line near the heat pump or air conditioner condenser (outdoor unit)?

Why is the mini-split ductless air conditioner installed in a sunroom enclosed with acrylic plastic windows called a “dehumidifier” on the building permit? 

How can I tell if my air conditioner uses freon? 

Can a grille covering a hole in the drywall ceiling be used for the required make up (combustion supply) air for a gas water heater or furnace in a garage? 

• What is the code for minimum height of air conditioner or heat pump condenser mounting pad/slab above ground? 

• Does the mounting pad have to be replaced to install at new heat pump or air conditioner condenser (outside unit)?

• What are the building code requirements for installing a heat pump air handler (indoor unit) in the attic? 

How did people stay cool in Key West before air conditioning? 

• What are the problems with underground return air ducts? 

• What is the required clearance for access and working space in front a heat pump or air conditioning condenser (outside unit)? 

• What temperature is too cold for a heat pump to work? 

• What are the exhaust fan requirements for a mobile home bathroom? 

• What are the exhaust fan requirements for a mobile home kitchen? 

• How much clearance is needed around an air conditioner? 

• What is maximum power cord length to a window or wall room air conditioner? 

What is included in an air conditioner inspection by a home inspector? 

• Does a wall or window air conditioner need a dedicated circuit? 

• Is a range hood exhaust fan required to vent outside? 

• Can a water heater and air conditioner use the same drain? 

• Does a home inspector determine if an air conditioning system is adequate for a house? 

• Does a home inspector test the air conditioning system? 

• Can a Type B vent connector be run horizontally? 

• What is the correct size breaker for the tons of my heat pump or air conditioner condenser? 

• What is an electric heat lock out on a heat pump? 

• Can the flexible ducts under a mobile home be on the ground? 

• Can the disconnect for an air handler be inside it? 

• Can I use a flexible duct for my range hood?

What are the code requirements for a range hood duct? 

• What is the average life expectancy of house a/c and heating ducts? 

• How long does a home thermostat last? 

Does my house need a heating system to pass a four point inspection? 

Can an air conditioning condensate drain pipe connect to a sink drain?

• How can I make my Florida air conditioner last longer? 

• What is the difference between an upflow, downflow, and horizontal air handler or furnace? 

• What is the difference between a fan coil unit (FCU) and an air handling unit (AHU)? 

• Does code require a p-trap in an a/c condensate drain? 

• Where can a return air opening/register NOT be located by code? 

Why is there a burnt smell when I turn on the heat?

Why does my air conditioner keep shutting itself off? 

• What does an orange or yellow flame at gas furnace mean? 

• What is an RTU air conditioner or heat pump? 

How energy efficient are window air conditioners compared to a split system whole-house air conditioner? 

• Why can't I use duct tape on heating and air conditioning ducts? 

• What is the best location for a heat pump condenser (outside unit)? 

What is the best location for a heat pump air handler (indoor unit)? 

• Why does my home still feel humid and muggy with the air conditioner on?

• Why are there wires sticking out above the  condenser fan motor? 

• Why is the air conditioning temperature split (delta T) fluctuating up and down while the system is running?

• How close to the property line can I put an air conditioner? 

• Why does it say INSTALLATION PROHIBITED IN THE SOUTHWEST on my air conditioner label?

What is short cycling of an air conditioner or heat pump? 


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