Terence McCann

Ask for your installation manual.

I think Dave was looking for a personal recommendation - not go to the local bookstore. He most likely has thought of that already.

You don't need to insulate the exhaust pipe. The problem is the moist exhaust gas is coming back into the intake from the where it discharges outside. It starts to freeze, the fresh air gets cut off and the furnaces stops running. Is there a screen on the fresh air intake? If it is a separate exhaust and intake a simple fix would be to put a 90 degree elbow on the exhaust and intake air, where it exits the home, and turn them so that they are pointing away from each other. This will divert the exhaust gas from the intake. You don't need to glue them in place, just put them on, as stated, and see how it works. You should get in touch with you local Trane factory rep (found though an authroized Trane HVAC company). If it is installed wrong, and it sounds like it, the installing contractor needs to correct their mistake, no charge. Right now the vicinity of the dryer vent is the least of your worries.

Perhaps a "New to the business" corner or some such forum addition. BASHI has something akin to it.

So, is the stove in Jeff's picture unsafe?

Hey Jeff, you ever play with the Yardbirds? Heard that one before eh? Attached is a CodeCheck pic of wood stove clearances. Check with the manufacture too. They have clearances in the install manual. Click to View 50.66 KB

It's most likely a bad flame rod (sensor). It is possible to get a defective new one (hair line crack in the ceramic). Make sure they replace the wire that connects to the flame rod too. Also, you may want to consider a new HVAC contractor too. It's easy to just keep replacing parts, at your expense, until the furnace works correctly. However there are correct ways to troubleshoot without being a parts replacer. You won't have to replace your furnace.

Where did you get the book Mike?

Ok, how about 85? Just pulling your leg. It is a fair question though. Home inspectors inspect homes when it's 90 outside. What will happen if they run the heat pump in this condition? Even though the indoor blower may move more air that's not the issue. Even if you sped up the indoor blower that doesn't change things. In fact if you look at fan curves you'll see there is a law of diminishing returns - more RPM actually equals less airflow. It has to do with coil design. Anyway the original question was energizing electric strip heat/emergency heat during summer months which is fine to do. It's basically an electric furnace at that point.

Is it safe then to run a heat pump, in the heat pump mode (running the compressor), when it's 90° F outside ambient?

Got to be a typo right? The Red Cross is assisting 17 people who live in the homes on either side of the imploded home. No word on when those residents will be able to return home. A CRT, when hit, implodes.

It's not a matter of the coils being matched, they are (assuming it was installed correctly, no retrofits improperly installed etc). It's a matter of total heat of rejection. As stated before, the surface area of the condenser is much greater than the surface area of the evaporator. The amount of heat that the condenser will pull from the air, in the heat pump mode with high ambient temperatures, is more then the evaporator can reject which will cause high head. Now, will it be a problem at 65, 70 or 75° F - probably not. If we shift the outdoor temperatures though and use 90° F as an outdoor ambient can we run the heat pump, in the heat pump mode, with out any problems - no. It will most certainly cause a high head condition. However at 90° outdoor ambient can we run the heat pump in an air conditioning mode - yes. It's not a matter of the coils being matched. It's about surface area and heat of rejection. Having said that though we, as home inspectors, need to default to the recommendations of manufactures. It's defensible.

Got one in a barn somewhere Bill? []

I've seen quite a few condensing units that the owners dog(s) have turned into a hydrant. The urine will strip away the fins leaving bare copper tubing behind. Amazing how corrosive urine is to the aluminum fins.

Yeah, but with some sour cream, chives and some bacon bits both will be delicious. ONE TEAM - ONE FIGHT!!! Mike But hard on the choppers.

It may have been running if the thermostat was set for automatic operation. Did you happen to notice the switch setting on the thermostat? Is this a heat pump? I've seen external crankcase heaters that get pretty hot.

I think that was a guess over at ASHI too Mike.

Bill, The attached picture was posted over at the ASHI forum. It read: "This machine is in an upper floor of a hotel that was built in 1891. Does anyone what it does?" If there is anyone who knows it's you. What is it? My guess is either food service or housekeeping. But its function I know not. Click to View 88.81 KB

Amen. They're junk. Ranks right up there with clothes dryer vent diverters.

That was good for a chuckle.

When we installed high end computer room air conditioning we always install vapor barrier behind the drywall. If we didn't the moisture would just shoot through the drywall to the exterior skin making humidity control damn near impossible. This was back in the days where large main frames weren't very forgiving - 70F with 45% to 50% RH. Trying to maintain 80% RH @180F without a moisture barrier is going to be impossible. The delta T will really drive everything to a cooler place. Also, I'm not sure how 80% RH is going to react with plywood? Have you done this before? I wonder if Greenboard, Wonderboard or Hardibacker might not be a better bet.

You can call their company for this type of question(s). Also, I would imagine the more penetrations in the barrier the less effective it becomes.

That would have been me Mike. I'm going to hate myself for doing this but this is the link for that thread: Radon Update

The original question was regarding a Trane unit and I'm pretty sure they don't use sequencers.

Just change the nozzle and filters once a year. It's cheap and good PM. No reason to over complicate it.