Shutting down a house for winter

Q.    Our home in Vermont is well insulated and has vinyl siding. We would like to shut our heat off for four months between January and April. Would it ruin our drywall walls?

Freeze Monitor
Freeze monitor dials phone numbers if house temperature drops too low.

Our heat is gas, forced air, and our finished basement has a bathroom and gas stove. What would you suggest?

A.    You are taking a chance. Prolonged, very cold temperatures would eventually penetrate the house unless there is a source of heat. It is safer to simply lower your thermostat to 45 degree F. and arrange with a family member, trusted friend or neighbor to keep an eye on the house.

There are warning devices that would ring one or more telephone numbers if the temperature drops below the limit set on your thermostat. Such devices can be found at

Use of a humidifier when heating with wood

Q.  We supplement the heating of our home with a wood-burning stove. To counter the excessive dryness in the house we use a humidifier. My husband places the humidifier next to the stove, with the moist air blowing at the stove.

His theory is that the fan in the humidifier will now be circulating warm, moist air.  I contend that the moisture evaporates when it hits the stove. Your comments would be appreciated.

A.  I love questions like yours, because I can truly say that you are both right. The humidifier blows the moist air toward the stove and is carried with the rising hot air, now humidified, throughout the room. The air from any humidifier is absorbed by the air, and you can say that it evaporates into the air, as long as the ambient air is not saturated – seldom the case in winter.

Soot gathers in house that is heated with gas

Q.  I have a gas furnace with radiators and hot-water heat but I seem to be getting black sooty film over my walls and windows. The gas company says that gas is clean and it must be something else. I closed up a wood stove in my rec room, relined my fireplace, re-vented my gas dryer and opened a vent closer to my furnace for better combustion but still have the problem.

It is especially heavy around my windows and TV screen. I wash my windows frequently because of this and repaint my rooms every two years. This has been an ongoing problem for several years, since I converted to gas from oil. No one seems to be able to find out the cause. Hoping for your assistance.

A.    If your boiler is an old style that is vented through the chimney, it draws its combustion air through any openings, cracks and crevices in the house (fireplace, wood stove and around older windows).

If the flues to the wood stove, the fireplace and the boiler are next to each other in the same chimney, and there are flat caps on them, when the boiler fires up, its gases may be drawn back in the house through the wood stove and /or the fireplace flues. And if the boiler’s flue was not thoroughly cleaned at the time you changed from oil to gas (as it must be), the oil deposits on the flue walls are desiccated by the heat and drawn into the combustion gases of the boiler. The clean combustion gases associated with natural gas are now contaminated with the soot from the oil and are recirculated throughout the house.

Another possibility is that, if you use the fireplace, it may draw its make-up air from the boiler flue, thus drawing the desiccated oil particles into the house.

Have the boiler flue thoroughly cleaned by a chimney sweep; remove or change the caps to tunnel-type caps parallel to each other (never facing each other) and see if that does not improve the situation.

Insulating a home built with terra cotta blocks

Q.  We have an old house made out of terra cotta block from top to bottom. We recently insulated the inside walls with R-13 and drywall. Then we had our outside done in vinyl siding and the foam insulation 3/4 inches thick. Our house is still a little chilly at 69 degrees. Any suggestions on how to keep our house warm? Also we were going to invest in a pellet stove. Any suggestions on this?

A.  I assume you studded the inside of the house’s exterior walls and put R-13 fiberglass between the studs. That, together with 3/4-inch rigid foam, gives you  walls with only R-17 – not too exciting for a cold climate.

There is also the possibility that convective currents within the terra cotta blocks rob you of some of the R-factor. This is difficult to overcome unless the blocks had also been filled with insulation.

It would have been preferable to apply 1-inch thick rigid foam insulation directly to the terra cotta walls and then stud the walls, if you have the space, with 2-inch by 6-inch studs and R-19 fiberglass insulation. Then outside, I would have used 1-inch thick rigid insulation instead of 3/4-inch. This would have given you an R-29 plus.

Now it seems as if your only option is to get warmer with a pellet stove. Pellet stoves are very effective and, as long as pellets are readily available at reasonable prices, they are a good way to go.

Pipes freeze after furnace is moved from crawl space

Q.  My wife and I recently bought a small ranch that had an old, inefficient furnace in the crawl space. During the fall, we disconnected the old furnace and decided to install a new furnace in our attic space and run new ductwork. Things seemed to be fine until we had a sustained cold and windy period which froze our water pipes. We did not take into consideration that the old furnace in the crawl space was emanating enough heat to warm the space and keep the pipes from freezing.

I purchased an electric heat tape and fiberglass insulation, and applied it to the area that I believe to be most susceptible to the freezing (along the foundation wall running almost the full length of the house). We again went through a cold spell and the pipes froze, despite the heat tape.

I have received many recommendations for fixing the problem ranging from heating the space to re-piping with technology that has the heating element within the pipe. Any suggestions you may provide will be appreciated.

A.    It was a mistake to put the new furnace in the attic. The heat it generates will cause snow on the roof to melt, thus causing ice dams to build up at the eaves. This can result in leakage inside the walls, wet attic insulation and damage to wall and ceiling finishes. There is also a loss of efficiency as the furnace is in a cold space that is presumably ventilated; any benefit from the furnace’s stand-by losses is lost. If the furnace had been left in the crawl space, its stand-by losses would warm the crawl space, keep the pipes from freezing, and warm the first floor.

Since it is unlikely that you will go to the expense of returning the furnace to the crawl space, and if the insulating you have done is not as described below, I suggest that your first step be to seal any cracks admitting cold air anywhere around the foundation; this will keep the wind out. You should caulk them.

If there are any vents in the foundation, please close them and place insulation over them. If you haven’t done so, this is how the crawl space should be insulated: put R-19 fiberglass between the band joists with a vapor retarder facing inside the crawl space; insulate the walls down to two feet below grade with either fiberglass or rigid insulation.

It is not safe to go below the two-foot level as it could result in walls cracking under the influence of deeper-penetrating frost. This should prevent further freezing of the pipes that are surely just under the first floor joists, as the earth’s warmth and the heat loss from the first floor should keep them above the freezing point.

You should also insulate the water pipes with neoprene insulation you can buy in hardware or building supply stores; they are easy to install. However, if you have already insulated as described above, and insulated the pipes, you may need to provide a modicum of heat. I know of old stone cellars in which pipes used to freeze until a simple 100 watt light bulb was kept on during cold weather and proved to be sufficient to keep the pipes from freezing.

Installing light fixture on a ceiling that has heating cable

Q.    We have electric ceiling cable heat. In our living room, we want to add a chandelier but we are concerned if we can do it with ceiling cable. Our house is 30 years old and it does not have any light fixture on the ceiling presently.

A.    I assume that you will have a licensed electrician do the installation, as you should. The safest way to do what you want is to use wire mold, but extreme care must be taken not to hit one of the ceiling wires with any driven fasteners. For that reason, it is best to use adhesive.

House dust causes family arguments

Q.    Hope you can settle a disagreement between my husband and me. Our home is 21 years old. We live directly across the street from the bay. This house is the dustiest house we have ever, ever lived in. I can dust one day, and the very next, it looks like I haven’t dusted in a month. I see advertisements to have your duct work cleaned, but my husband insists it has nothing to do with any duct work and the dust is entirely due to the fact that we live on the beach.

I have come to hate this house. I see particles floating in the air despite vacuuming, dusting, cleaning on a daily basis. I have grown weary and do not want to spend every waking hour cleaning. I do not find this normal; he is constantly complaining about the dust and pet dander (one dog could not possibly create such dust, right?). I just do not know what to do.

Could it be the AC ducts or the heating system? I believe we have hot water radiant heating; another factor I believe could be the culprit. We have most of the baseboard heating  blocked off by heavy furniture and TV surround system so I am unable to vacuum those areas by my lonesome. We had to have extensive repairs on our mega screen TV because — and this is what the TV repair man stated: “It needs to breathe and be vacuumed every 3 months” — something I cannot do.

I believe if we rearranged some of these rooms and I had access to baseboards so I could vacuum, it would help tremendously. The great room in particular where the big TV is. My husband is unwilling to budge on rearranging furniture and thinks I should vacuum 2 to 3 times a day. I am getting too old to vacuum that many times a day. Hope you can help ME (us).

A.    Not being Dr. Phil, I can only respond to the dust problem. It sounds to me as if you have a very drafty house with poor windows.

Since you have baseboard heaters, you do not have radiant heat as radiant is used to describe heating systems in floors or ceilings; you have convection heating. The air-conditioning ducts may need to be cleaned yearly; it might help — it’s worth a try. If your air-conditioning system does not have an electronic air filter, you may want to have one installed; they pick up a lot of microscopic particles.

Other choices are (and I am sure you have thought about them) to move to a less windy and cleaner area; hire a cleaning service to come and move the furniture and do a thorough job once a month, or more often if necessary, to keep peace, or simply get used to having a house less clean that you would like it to be.

Heat lost in complex network of ducts

Q.  We purchased our home 16 months ago and realized last winter that the heat in the master bedroom is insufficient. The room was added to the dwelling by the previous owner three years ago and was heated/cooled via a flexy ductwork tube, which began in the basement, snaked up the side of the house then branched into four separate flexy ducts in the attic, entering our room through four vents in the ceiling (whew!).

I have been told by my HVAC technician that this is too far for the air to travel efficiently (by the time the air came through the vents, it was cold). We have since disconnected this contraption and have boosted circulation to other rooms in our home (air was being leeched-off the main duct for the master bedroom). But we are now left with a very chilly bedroom.

My question: Do we abandon all of the ductwork above the ceiling and install baseboard heat? Or do we look into a heat-pump system, which I understand is a bit expensive? The room stays comfortable in the summer, so we have gotten by without a window unit. Heat appears to be the biggest obstacle.

A.  You are right! Whew! Who ever thought this system up? The air running through a duct or ducts from the basement to the bedroom on the outside is bound to become cold by the time it reaches its destination.

Ask your HVAC contractor for his or her advice on the most practical way to increase the heat in the bedroom. A separate through-the-wall unit or even electric baseboard  may turn out to be the best solution if the present system cannot be satisfactorily extended within the conditioned envelope of the house.

If you have gas, you may want to consider having your HVAC people install a through-the-wall Rinnai heater. These heaters are very efficient and can easily be sized to fit the need of your master bedroom.