Your questions, Our Answers

SearchAsk
See Answer
attic fan on roof

What’s the Best Temperature for Attic Fans?

At what temperature should I set my attic power vent fans to keep my attic cool? I live in a hot and humid climate, where temperatures are often in the 90s. The roof gets full exposure to the sun throughout the day.

Our Answer

Attic ventilators generally turn on between 90 and 110 degrees Fahrenheit.  That said, attic fans are not the best choice for cooling attics, especially if you have central air conditioning.  The reason is that attic fans depressurize attics and can rob air conditioned air from the main body of the house, greatly decreasing efficiency.  It essentially pulls that cooled air through cracks and crevices in the attic floor, and also through holes that allow for wires and pipes.
A much better cooling option is continuous ridge and soffit venting.  Basically, you cut a slot in the top ridge of the roof and put a vent right over it.  As the wind blows over the roof, it depressurizes the ridge and sucks the moist warm air from the attic.  Everything you want to vent from the attic gets sucked out of that ridge through the depressurization that happens through the normal wind cycle.

See Answer
central air conditioning systems, HVAC

Air Conditioning Options: Choosing the Air Conditioning System That is Right for You

I would like to install air conditioning on the 1st floor of my 2 story home.  I have casement style windows that swing out so I can't install a window unit. I could install central air, but I don't use the 2nd floor of the house.  The windows are 10 yr old Anderson.  Should I replace 1 window with a double hung window so I can fit in an air conditioner or should I opt for central air?

Our Answer

My first choice for energy efficiency, as well as overall comfort in air conditioning options, would be to install a central air conditioning system.  Central air systems can be zoned so they will only cool one floor of the home and not both.  However, you certainly should plan on both and discuss that with your contractor as it may be less costly to install some of the ducting to get ready for cooling the second floor at some point in the future.

Another option might be to install a through-the-wall air conditioning unit.  Many of the larger air conditioning units are available with wall mounted sleeves.  To install, you'd need to cut a hole in the exterior wall and frame it out the same way you'd frame an opening for a window or door.  It is very important to do this correctly, as you will be impacting the structural integrity of the house.  Also, this type of system will very likely cause a heat loss in the winter, as it is very difficult to seal it to prevent cold air leaking in. 

A better air conditioning option, which cost-wise will be in between the cost of a central system and a through-the-wall mounted portable, might be a ductless split system.  I have Fujitsu system like this in my office and it works extremely well as a supplement to my central system, which doesn't fully extend into the office space.  With ductless air conditioning, you have a wall blower that hangs on the inside wall of your home.  This is connected via a refrigerant line to a small compressor which sits outside, just like a central system.  The compressor supplies chilled refrigerant to the blower inside, which circulates the cooled air.

Given the above air conditioning options, my choice would be (1) central; (2) ductless; and (3) through-the-wall. Regardless of what you ultimately decide with the air conditioning options, you should be certain to choose the most energy efficient unit possible.  The Department of Energy' has excellent to help you understand cooling efficiency and options.

See Answer
central air conditioning systems, HVAC

How Can I Tell if my AC is Leaking Freon?

What is the better way to check a freon leak - a dye test, or an electronic device? I have had about five pounds of freon leak over the past nine months. My home warranty plan refuses to send out another company to check for the leak using the dye test.  They say "wait 60 days & see if the leak can be found."  What do you suggest?

Our Answer

First off, you're not the best person to be searching for a refrigerant leak - which, by the way, may or may not be freon depending on the age of your AC compressor. 

Rather than check for actual leakage, check for performance.  Here's how:

Measure the temperature of the air inside the house at a return duct, then measure it at a supply duct nearest to the air handler.  If the system is performing normally, you should read a 12 - 20 degree differential.  If the differential is less than twelve, you're well within your right to demand repair. 

As far as your home warranty company's refusal to address this problem, this is unfortunately somewhat typical, and I can only suggest you be very persistent with them, and always ask to discuss the matter with a supervisor.  Good luck!

See Answer

Ceiling Fans for Heating and Cooling

What direction should the blades turn during warm months and cold months? I was always told that the blades push the air down during warm months and pull air up during cold months.

Our Answer

Most people don't know that you can use a ceiling fan in both the winter and summer months.  During the winter, set your ceiling fan to turn clockwise to move rising warm air, down into your room. When the weather heats up, set the fan to turn counter-clockwise for a cooling breeze.  

See Answer

Attic Ventilation: Impact on Air Conditioning Costs

Does opening the door to the attic have a affect on the AC efficiency in the house? In the hot weather, I keep my 2 garage doors open and the back rear door to get air flow to keep the garage cool in the Arkansas summers. I also have a screen door to the attic which has steps to walk up (unfinished and insulated) and is located in the garage. I use this to ventilate what little air that will get up the steps to the attic which has several attic spinners. In listening to your show I hear you tell people not to create a void in the attic and that house AC will be drawn to it? I am in an all electric house and actually my electric bill has been very reasonable. I use a setback thermostat and cool the house mainly early evening till midnight.

Our Answer

Using an attic fan can have a negative impact on AC costs as the fan will depressurize the attic drawing cooler, conditioned air into that space and out to the environment.  It sound's like in your case the attic may be over the garage?  If that is the case there is no issue.  If the attic is indeed inside living space, then leaving it open will not help your cooling costs.  

This said, most of the concerns stem from the use of attic fans and not passive venting which is what you've described. More here about attic fans and air conditioning.

See Answer

Heat Pump vs. Gas Furnace

I'm considering having a heat pump installed in a house I'm closing on next week.  The house is located in western Pennsylvania, and currently has a gas furnace but no cooling.  The idea of taking most of the heavy lifting of the gas furnance and going cooling in the summer seems like a good idea to me.  Do you agree?

Our Answer

My advice? Don't do it.  It's never a good idea to install a heat pump when you have available gas service.  The cost of heating with gas is always less expensive than heat pump heating costs, especially in cold climates like the one you experience in western Pennsylvania.  Heat pumps are more valuable in warmer southern climates, where temperatures don't frequently dip below freezing. 
That said, chances are that your existing duct system needs to be updated to properly install central air conditioning and cool your house.  Considering you only have a furnace, those ducts are probably smaller than they would be if they were designed to carry AC - which would be the case regardless of whether the house currently uses a heat pump or a gas furnace.  They also might need to be relocated, because with air conditioning, you want to have supply vents at both the ceiling and the floor.  So adding central air conditioning to your home might require a hefty investment either way, but under no circumstances should you give up a gas furnace for heat pump. 

See Answer

Uneven Heating and Cooling Throughout House – What’s the Cause?

I have a brick three-bedroom rancher built in 1974. We blew insulation into the attic when we moved in, and last year installed brand new windows throughout the entire house. Yet when I close the doors to two bedrooms they get warmer in the summer and cooler in the winter. A lot of air that comes from the registers. There are also 31-inch air returns on the walls in both rooms. Is it possible that these are too big for the rooms and causing this problem?  Or could it be something else?

Our Answer

If registers are letting air into rooms from unconditioned spaces, like an unfinished basement or crawlspace, it could be the cause - or at least a contributing factor.  Hire a HVAC contractor who can measure airflow through those registers.  If the registers are damanged or perhaps not even fully open, it could account for differences.

See Answer

Sprinkler Head Hitting AC Unit: Problem?

Recently a house was finished being built next to mine, they laid the sod this weekend and now have the sprinkler head about 3 inches from my heating and air conditioning units. I want to know if this will hurt the units or cause me problems that result in repairs later. Should I go move the sprinkler away or is it ok?

Our Answer

Certainly an excessive amount of water on your exterior compressor unit is not good.  I think if you can direct it away from mechanical equipment you should, and then there would be no issue.  I hope this was installed on their property and not yours.  You mention it being 3 inches away which we're presuming is a typo.
 

See Answer

Newer Geothermal HVAC System Leaking Refrigerant

Our 3 year-old geothermal 1-ton attic system occasionally shuts off.  Each time it does, we're given a different reason for the shutdown. The most recent shutdown was caused, we were told, by low refrigerant levels - they said we needed 2 pounds added. Incidentally, we noticed our most recent maintenance agreement was changed from the prior two agreements to omit, you guessed it, 2 pounds of refrigerant added if needed. So we had to pay for the refrigerant.

Now I'm wondering what comes next. If we need refrigerant there must be a leak, right?  Or does it somehow evaporate in the system over time? Our geothermal system is still under warranty. I want to approach the business that installed the system but thought I could use more information beforehand. Any thoughts on this? Is it common? Is this toxic?

Our Answer

Indeed, this is very suspicious. 
One of the common fears and very real pitfalls with geothermal systems is they require impeccable installation, and are prone to leaking.  Once that leak springs, it can be very expensive to repair because accessing those coils can be near-impossible. 
I also think the warranties offered on these systems are somewhat misleading.  Let's say a system is warrantied for fifteen years.  Often, that warranty will cover the cost of the coils, but not the cost of labor and installation. 
You have enough history to document what's happened.  Put that info into a detailed, direct letter.  Then take that letter to both the manufacturer and installer and ask them to address it.  You want to address it to both of them, jointly, because both of them are potentially liable.  Your system should not be leaking refrigerant at these levels.

See Answer

How to Reduce the Dust Level in a Home

There is a fine dust that seems to be coming from the heat pump that gets on everything. The heat pump has been looked at and cleaned, and no one can find any problems. Any ideas? Thanks.

Our Answer

Basic fiberglass air filters do very little to trap dust and fine particles. It may be wise to consider investing in a high-efficiency electronic air cleaner. They can trap even virus-sized particles, and can certainly handle dust.

See Answer

Central Air Conditioning Fan Making Loud Noise

Just last week, the central air conditioning fan inside my home started making a constant loud noise.  What could be causing it?  Could the fan be hitting something?

Our Answer

There are several possible causes for a noisy forced air system.  When a fan's bearings begin to wear out, it's generally characterized by a lot of vibration and racket.  There's also the possibility the fan is baked with dirt or dust, which is forcing it out of balance, again resulting in noise. There's also a chance something inside the compartment has gotten loose and is rubbing against those fan blades.  To get to the bottom of the problem, have the fan thoroughly evaluated by a HVAC tech.  While that tech is in your home, make sure he or she also services your entire system for the upcoming season - whether it's summer coming up, or winter. 

See Answer

Keep Heating and Air Conditioning Vents Open or Closed?

Last year I purchased a 50-year-old home. Central air and heating were installed about 12 to 15 years ago, which included five vents in the basement. I had an energy conservation expert from the local electric company do a survey of the home. He suggested that I seal off all five vents in the basement since there was no living space down there. A little later my HVAC expert came to examine the system. He said I needed to keep those vents open as the system was designed to move air through those vents. Otherwise, I was building up too much pressure, causing extra strain on my HVAC system. What's the best way to go? How can I be the most energy-efficient and save money in the long run?

Our Answer

Generally speaking, shutting off registers should not add any kind of strain to the system. One thing to be aware of with respect to basement ducting: Make sure any return registers are left open because that pulls air back to the heating system to be reheated and re-cooled. That would include any damp air in the basement, which keeps the basement drier. One caution with regard to basement returns: An HVAC expert should make sure they're not located too close to the furnace, as that can cause the room to depressurize and combustion gases to be drawn into the house.

With all that said, I don't expect you to get a significant savings on AC by shutting off the basement registers because the thermostat that controls whether the system is on or off is most likely upstairs, away from that room.

See Answer

Home Addition Won’t Stay Warm. What Can I Do?

My house has a small room that was added on to the back of my attached garage.  It's about 6 feet by 12 feet.  There are two outside walls, one common wall to the house, and a common wall to the garage.  When I moved in, I added R13 value insulation to three of the walls. 

There's an HVAC vent on the interior wall and I also added a small electric strip heater, yet the room is constantly colder than the rest of the home.  The insulation helped a bit, but not as much as I hoped.  Any ideas?

Our Answer

This room is crying out for its own HVAC system. Often when rooms are added onto existing structures, the person constructing it thinks, "I have a duct, so I'm simply going to put a hole in the wall and add a register."  But forced air systems don't just supply heated air - they're effective because they pull cool air back to the furnace to be reheated, too.  I'm guessing you don't have return duct that does this, and the small heater you added is outpaced by the cold air. 
This is a good opportunity to consider a split ductless system.  I think it will give you you the amount of air conditioning and heat you need for this small space.  Installing it will be less expensive than installing a central system, but isn't inexpensive.  However, split ductless systems are very efficient, and often qualify for a variety of tax rebates and tax credits. Good luck!

See Answer

Why Do You Only Recommend ASHI Home Inspectors?

Why do you only mention ASHI? There are several other home inspector societies out there that are the same as ASHI and quite frankly, some are even better. IE: they require stricter standards for the inspectors! There is nothing wrong with ASHI, but having always believed this is a nuetral based information site, I am surprised there is no mention of others, or at least a mention that there are others? Locally, several of the "good old boy" home inspectors are ASHI members, they don't comply with hardly any of thier standards, these guys are in and out of a 2500 sq/ft home in minutes, no attics, crawl, or any other detailed areas are inspected. More of a "need this just to satisfy the bank" kind of inspections. There is no one at ASHI or any of the other societies for that matter that are following inspectors around to assure they are doing a thorought job. I recommend to people to get online and look for ratings, such as Homeadvisor or Angies list provide. Also, ask for references from past clients, etc.. Caveat Emptor!

Our Answer

Let's just say it sounds like you have a dog in this hunt, as the saying goes. 
I spent 20+ years as a member the American Society of Home Inspectors (ASHI).  I believe they are the best means of assuring that a perspective homebuyer is finding someone qualified and confident in home inspections.  In my view, ASHI's standards are among the strictest in the nation, test among the most comprehensive in nation, and that the formation of other organizations is likely a response to the fact that many home inspectors don't want to put out the time and trouble needed to meet ASHI's requirements. 

See Answer

Cooling Air Conditioning

live in kansas. on farm. home owner. been thinking of puting in a hydro a coil. can i hook this up to my water well and drain to the garden? or will i be required to use the refrigerant unit. also what problems may occur if either way is chosen?