Well, heat pumps must be understood in the same manner. Essentially, heat pumps are devices that, uh, PUMP HEAT! They do this either mechanically (such as, a fan or blower), or a chemical (such as freon or refrigerant). Heat pumps can be used to pump cool air into a building, as well. There are types of furnaces that are heat pumps, as well as other units for swimming pools, air conditioners, water heaters, etc. This website has everything you need to know about heat pumps, including heat pump prices and a very good explanation of how they work, what they do, and the development of technology involved with them.

Listen, if you are planning a renovation or building a home, get informed about your heating system before you install it! I’m sure my house is just an aberration (I hope so), and the screwy heating system isn’t all that common. The heating and cooling systems in your house are going to be there a good long time. Make sure they’re done correctly, and make sure you get the best bang for your buck, too. Check out the website for information and on getting the best price of heat pumps.

Answer: no.

I want to address this issue again. If you have a forced air furnace, realize that there is an exchange of air going on with it– cold air to hot air. Your furnace needs to take in cold air, heat it up, and blow it out through your heater vents as heated air. If you cover your cold air return vents, you are starving your furnace, creating an air vacuum in your home (leading to an uncomfortable atmosphere), and perhaps filling your home with trace amounts of carbon monoxide.

Do not cover your cold air return vents.

I did a post about this when I renovated my living room, and re-did some of the furnace ducting to the room. I had done some studying and talked with my furnace guy. You can read the post here. You can also read my recent post about changing your furnace filters– it’s an easy chore, easier then changing water filters anyway! Not changing dirty filters can damage your furnace and wind up costing you more money on your heating bills, too.

Now, my home has cold air return vents, but not enough. Not only do you need vents, you need a proper amount for proper air exchange. My house, at about 1680 square feet, only has two small cold air return vents– for the entire house! That is far too few. My Furnace Guy said that for every heater vent (and size) in a room, there should be a cold air return vent. Bedrooms almost never have them, and this explains why bedrooms are so cold in the winter– there is no full air exchange but rather a vacuum of air. The heated air really has nowhere to go, since there is no air flow; and the room air remains stagnant and chilly. So ideally, every room should have a cold air return vent (or at least larger ones in key areas of the home). I know! This sounds awful, because with duct work, you have to rip out walls and work with metal. It’s NOT fun. However, the next time you have a wall open or if you decide to build an addition to your home, keep these things in mind. Your furnace will appreciate it, and it will show in the heating bills.

And in the meantime, keep all those cold air return vents uncovered!

Photos courtesy of Americanhvacparts and Office of Energy Efficiency of Canada.

One of the nicest things you can do for your furnace is changing the filter regularly. But how often does one change the filters? I’ve done a little research, and the answer is: it depends. Haha! Seriously, it does depend on your furnace, your house, and your lifestyle. If you have a lot of pets and a huge drafty dusty home like I do, you should change your furnace filters every month. If you use your furnace irregularly, have no pets, and have a smaller home, every other month or every three months are fine. Most furnaces come with recommendations in the manual; always check that first.

The main purpose of the furnace filter is to protect your furnace’s delicate moving parts from dust and dirt. And some filters come with extra benefits, such as capturing very small particles of dander, dust, and allergens. I only use those now. You should see how quickly they fill up with gunk!

I read a review at Consumer Reports a while ago, and they did a test on furnace filters. The “cheapo” brands (the ones I always got) were horribly non-effective in filtering dust and allergens from the furnace system. The filter that got the highest grades were those by the manufacturer 3M. Those are the only ones I purchase now; they’re called Filtrete Micro Allergen Reduction Furnace Filter. They are, obviously, more expensive than the cheapo ones, but at least they do the job! And we change them every month (well, try to). So I am always looking for deals. I used to get them from my local Big Box stores, but have recently found the filters I use at Buy.com. They come in a pack of 6 and the shipping is very inexpensive. Sometimes you can snag some when there’s a good sale; however, at this time of year, sometimes things are out of stock. Don’t ever wait to order seasonal stuff like this!

It’s important to change your filters regularly. Leaving filthy filters in your furnace can cause the furnace to overheat and shut down; installing insufficient filters can cause dust and dirt to pass into your furnace motor, clogging up the works and reducing the efficiency of the furnace (which means more expensive heating bills). Be sure to change your filters regularly! And if you’re looking for some good prices and great service, check out Buy.com’s inventory.

Well, I got a question from a guy named Barry who lives in Vermont (a climate just like New York State).

In my old Vermont house, with an oil furnace, I’ve got two vents clearly, forcefully, blowing cold air out into the house. Because of this, it seems impossible that they are cold air *return* vents. How can I confirm that they aren’t? Second question: can the furnace itself have the only cold air return vent?

I wanted to post his question and my answer in a separate post, because I think it may do others some good, searching for more information about cold air return vents. Here’s my response:

Hi Barry. Well, I’m not a furnace expert, but what I’d do if it was me is this:

1.) Make sure your ducting system is set up right. If you look at your furnace (you’ll see all sorts of ducts leading everywhere), you’ll see an “in” large duct and an “out” large duct, with many smaller ducts branching off of those. That’s for most forced-air furnaces, anyway. Check and make sure you know where the ducting system branches off into, and become familiar with your furnace system.

2.) My hot air return vents ALWAYS blow out cold air for the final three or four minutes right before the furnace stops. This is because the furnace fan keeps spinning for a little while after the gas heating flames go out– this is natural, to ensure that all the hot air has fully pushed through into the room. It’s the normal part of the cycle.

3.) Maybe your hot air vents blow out cold air because they are either too far from the furnace (like a third floor) or you don’t have enough cold air return vents and the furnace is just blowing whatever air it can find (and in an old home in a Vermont winter, that would be cold air).

I hope those tips help.

When I first paid attention to my furnace system, I was baffled that cold air blew out of my heater vents. After asking my Furnace Guy, he informed me about the natural cycle of a furnace air system. I suspect this may be Barry’s thought, too. Some furnaces will blow and blow cold air for quite a few minutes before shutting off and completing the cycle.

So I hope this helps anyone who is searching for furnace answers.

Answer: no.

I want to address this issue again. If you have a forced air furnace, realize that there is an exchange of air going on with it– cold air to hot air. Your furnace needs to take in cold air, heat it up, and blow it out through your heater vents as heated air. If you cover your cold air return vents, you are starving your furnace, creating an air vacuum in your home (leading to an uncomfortable atmosphere), and perhaps filling your home with trace amounts of carbon monoxide.

Do not cover your cold air return vents.

I did a post about this when I renovated my living room, and re-did some of the furnace ducting to the room. I had done some studying and talked with my furnace guy. You can read the post here.

Now, my home has cold air return vents, but not enough. Not only do you need vents, you need a proper amount for proper air exchange. My house, at about 1680 square feet, only has two small cold air return vents– for the entire house! That is far too few. My Furnace Guy said that for every heater vent (and size) in a room, there should be a cold air return vent. Bedrooms almost never have them, and this explains why bedrooms are so cold in the winter– there is no full air exchange but rather a vacuum of air. The heated air really has nowhere to go, since there is no air flow; and the room air remains stagnant and chilly. So ideally, every room should have a cold air return vent (or at least larger ones in key areas of the home). I know, I know! Replacing and rebuilding your home’s ducting system is not as easy as replacing all the kitchen sinks! With ductwork, you have to rip out walls and work with metal. It’s NOT fun. However, the next time you have a wall open or if you decide to build an addition to your home, keep these things in mind. Your furnace will appreciate it, and it will show in the heating bills.

And in the meantime, keep those cold air return vents uncovered!

Photos courtesy of Americanhvacparts and Office of Energy Efficiency of Canada.

I just wanted to let you know that it is very unadvisable that you cover these vents. I did for a few years until my Furnace Guy informed me of the details.

Your home needs cold air return vents. The hot air coming from your furnace entering your house must have a source. Unless you have a very sophisticated direct-vent furnace with supply air coming from the outdoors, you need return vents. This keeps the air in your house moving and reduces air pressure from the heater vent air filling your room.

Think of it as a fan in the summer. If you put your fan in your window and open the door, what do you have? Circulating air. What happens if you close all other windows and doors in that room and still run the fan? The fan blades still work, but the circulating air supply is almost entirely choked off, and the cool air no longer vents. It eliminates the fan’s efficiency. Moreover, it makes the fan run and you are still charged for the electricity to run the fan. You are essentially paying for nothing, plus wearing out the fan motor even faster.

A forced-air furnace needs intake air to supply the outtake air. To close off your cold air return vents chokes off the intake air supply. So it not only is costing you more money to do less, it is also making your furnace work harder to run.

My Furnace Guy said that, in a perfect world, every room that has a heater vent should have a cold air return vent. There is a mathematical calculation they use to determine how many return and supply vents a room and house needs. In my old home, I only have TWO small return vents. This is not good. I am trying to fix this, knowing that it is costing me more and making my new furnace wear out sooner. The worst thing I could do is cover my cold air return vents.

So… if you are wondering whether or not you can cover the cold air return vents– no, you can’t.

Just an interesting fact.

I’ve slowed down my renovations to a mere crawl these days. We are just too busy with school and fall/winter preparations right now. It has been…uh, interesting, using the fixtures on electrical system I installed. Nothing goes wrong, it is just me. I still remain jumpy when a light bulb goes out (oh no! did I wire it wrong?) or an appliance malfunctions (oh no! will it explode into a fireball?), but everything is really working as it should (no sparks, no flames, etc). So far.

Uncannily, we had a power surge during a horrific thunderstorm a few weeks ago. PEOPLE, BUY A SURGE PROTECTOR FOR YOUR COMPUTERS! During the storm, we heard this eerie, cackling zap throughout the house. Right after that, my daughter called me to the computers (which were on during the storm) as they mysteriously rebooted themselves and started spewing screwy BIOS information. Gulp. I shut off the power to the computers, restarted them, and, thank God, they seem to have recovered. I shudder to think of what might have happened had I no surge protectors. The rest of the electrical system here seemed OK (except for the digital timer on my coffeepot, which flashed Chinese numerals until I reset it). But it was a fright, to be sure. I also wonder if part of the problem was that the computers had not been plugged in to a grounded outlet area (the part of the house with the very old wiring). The next day we moved the computers to the part of the house that I had redone with proper, grounded wiring.

Other good news is that we finally got the thermostat for the furnace installed! On October 22nd (Monday)! Believe me, waiting that long to finalize the heating system in Upstate NY is risky. But the weather has been incredibly balmy in Upstate all month. No frost yet! Our frost date is usually about September 25th or so. I expect the weather to change at any time, however.

The problem with the thermostat was that… well, let me go back a little. Earlier in the summer I had removed it along with everything else when I gutted the Living Room. The thermostat wire had been plastered into the wall at some point when that part of the wall had been patched long ago. Needless to say I had to pry the very old and decrepit wire out of ancient, hardened joint compound, and the thermostat wasn’t too happy to move, either.

Unfortunately, I didn’t take a close look at how the thermostat was installed before I removed it. Oops.

So months flew by as we demolished, hacked, electrified, insulated, hammered, nailed, painted the room etc. Now I will say that I did have enough foresight in getting the proper wiring, placing it inside the wall, etc. Everything was set to install the thermostat until when it actually came time to do so. I just couldn’t figure out where to put the wires and where to place the screws. I didn’t remember how it looked when I had removed the thermostat….

I searched the internet for instructions and the most detailed I could find said, “For wiring instructions, see your installer.” Sigh. I have a great Furnace Guy, but this is peak season for him and not only was he hard to reach (I’d tried calling him a dozen times for advice but he was crazily busy) but I didn’t want to pay for a service call. My husband decided to tackle the thing. He studied the thermostat for a while and tried screwing in a few wires. I, in the basement, flipped the switch to see how it would go. Nothing. My husband tried moving some wires around, try that. Nothing. We were baffled. I was going to have to petition my Furnace Guy. Winter was coming and this fluky warm weather wouldn’t wait for us.

After two weeks of phone tag, my FG popped by. He took a long look at the thermostat and my husband’s wiring job. He scratched his head and asked, “And it doesn’t work?” He wondered if something was wrong with our furnace– that $4,000 furnace we got last year– brand new– after the flood–and whose warranty had just expired a week ago– that furnace. Gulp.

We double-checked everything: the circuit breaker (even though I had never removed the furnace circuit when I’d done the panel work), the wires, the junction boxes, the connections… time was ebbing away and my FG had to go soon. He tested the furnace’s electrical panel (with some very cool voltmeters!) when he suddenly said “aha!” He pulled out this tiny purple thing from the panel and tested it. It was the fuse to the furnace. Remember that power surge we’d had? It had blown out the fuse to the furnace. My FG said fuses are a great safety feature, because that tiny fuse absorbs excess electricity should any flow. If anything were to get by that fuse and zap the electrical panel, it would cost hundreds of dollars to replace. So that tiny little purple thing saved my new furnace. Neat.

The FG had an extra fuse on hand, he plugged it in the little slot, and voila! The furnace kicked in and started running! Not only was I thrilled that the thermostat finally worked, I was thrilled that my wiring work over the summer and my husband’s installation of the thermostat worked! Wow was I happy!

To put the icing on the cake, my FG said there was no charge for the service, not even for the cost of the fuse. What a guy! I paid him with a big bag of garden tomatoes and that seemed to make him happier than if I’d written a check.

Well, now we are really ready for winter. And given the weather forecast for the week, we did by the skin of our teeth.

I can’t even begin to explain how I did this job, it was so time-consuming and complicated. Cutting the metal with tin snips was the hardest part, I think. Also difficult was screwing in the sheet metal screws.

I do not consider my ductwork to be final. This is something I would truly like a professional to do. Working with metal, and that room by room, is enormously laborious. I had to do this room myself because the cost isn’t in the budget right now. I think I did a good enough job to last us a few years. By then I’ll probably hire my furnace guy to redo everything. Ductwork is pretty intense work. I have great respect for my furnace repairman.

I did not recycle as much of the old ducting as I wanted. This is mainly because the old ducting is 7-inch diameter. Modern measurements are 6- or 8-inch. I was in a real pickle, trying to make things match. I used a few adapters (6- to 7-inch) and I stuck with the flexible ducting. I suppose I could have bought all new 6-inch ductwork, but it would have cost a small fortune for this room.

Anyway, I think my adaptations are acceptable. I can rest easy that we are ready for winter now. The ducting is sealed good and tight. It is free from drafts and finally free from all those spiders making their nests in the holes.

Now that we are doing one room at a time, I am doing everything in one room at a time– walls, ceilings, electric, insulation, floors, ducts. It is not as efficient as doing all rooms all at once, but this method is more manageable for us (financially as well as for sanity).

So I right now, on top of learning everything else, I am learning how to repair and install furnace ducting. It is actually not terribly difficult, merely distasteful and dirty. The old ducting dates back to the 60s and some dates earlier. It is very, very dusty and rickety. Some pieces I am replacing but I am reusing most of the ducts. I spent a whole day removing everything that connects to the living room (two heater vents and one cold return vent) and scrubbed them clean. The cold air return vent was only sheet metal nailed onto floor joists in the basement, and a hole hacked into the living room floor as a “register.”

You can see the stone foundation and three floor joists through the “register” in the above photo. Unfortunately, the natural gas supply line was installed through the foundation and directly under this cold air return vent– not a very wise decision, because should the gas pipe ever leak, the fumes are dispersed throughout the house and also flow into the living room above.

When I peeled the sheet metal to reveal the joists, great gobs of greasy dirt and dust spilled out. Yuk. Thank God I was wearing a bandana to cover my long hair.

If you look closely at the picture below, you can see what I mean. This photo was taken before I removed 70 square feet of sheet metal nailed to the joists. I had removed the cold air supply duct (where the circle was) to reveal about a 1/4-inch layer of dust and cobwebs coating the joist above it. I am so glad to be rid of this filthy cob job.

There is a system to furnace ducting. You can’t just throw ducts anywhere. Cold air vents (return air) must be positioned in interior walls, and heat ducts and registers (supply air) must be installed along exterior walls. The system of forced airflow works with the natural physics of rising and falling air. Anything else is inefficient (and against some local housing codes). As expected, the ducting system in my house is all the wrong way.

There should be a cold air return vent in every room that has a heat supply vent. Only two rooms in my entire house have cold air return vents (the living room and dining room), and they are both along the exterior wall. Thus my furnace works very hard, and the air pressure in my house is uncomfortable (think of how a cup sticks to your face when you suck in the air from the cup– it creates pressure on your face because of the vacuum you created). Also, my upstairs rooms are absolutely frigid in the winter. One bedroom (15 x 17) has a teeny-tiny heater vent on an interior wall, and that’s it. The heat leaking out of that tiny heater vent cannot compete with the two 3′ x 5′ windows and the 250 square feet of uninsulated walls and floor of that room. All winter, a thick coating of ice covers both windows, and over the years the water has rotted the window panes. I won’t even go into describing the other bedrooms. We freeze every winter up there.

So, the fundamentals are important here: supply on outside walls, return on inside walls. Have enough heat registers for your room (there is a formula for calculating the necessary cfms to square footage). And have an equal amount of cold return vents for your heat supply vents.

So I am in the process of installing another supply of heat in the living room, replacing the dirty cold air sheet-metal cob job with a closed-duct system, and patching/sawing holes in the floor above to accomodate the changes.

This autumn, I have to add more cold air return ducting to the downstairs to make the system a little more efficient. Next year, when we remove the chimney, the new opening will allow me to completely reconfigure the supply/return ducting system for the second floor. The noggin on the first floor make ducting and electrical nigh impossible for exterior walls. I have to work around that!

For now, I am thrilled to be doing even one room as it ought to be done.