If you had a really old humidifier in a dinosaur furnace and you werenÂt sure if it was working or not, that would lead me to believe it was never serviced, thus probably didnÂt work.

The only true test to see if you will benefit from a humidifier besides the telltale signs of static electricity is to have taken relative humidity readings in your house at various times in the winter. Many thing effect the need or benefit of having a humidifier such as windows, cooking and bath ventilation.

One advantage of the new furnace is the flue. If you old one that had with a big flue and draft hood that was stealing ambient air along with humidity, causing cooler dry air to infiltrate on a constant basis.

No. Humidifiers need to be serviced at both ends of the season, a task rarely done by the average homeowner. Also the only really effective humidifer is a steam type that humidifies independent of the furnace. At the price you are quoted, I doubt that is the one your contractor is pricing. Save your money and if you need humidity in your bedroom to sleep, get a portable. You should be able to add one later at no greater cost.

I think the price is high since they will be right there working on/replacing the unit anyway. If money is tight right now I would punt the humidifier until down the road, I think it should not cost much more to add later than they are charging.

I do like humidifiers and even though they do require service it is no big thing to take care of. I have one and it pays for itself in a much higher comfort level at a lower temp in winter and my hardwood floors do better with it.

Bypass pad humidifiers which is 95% of the residential style sold in the US work fine and service required is a $10 media pad.

$450 is a common price to have one installed alone, with an equipment install at same time I have heard $250-$275 is common and should be able to be negotiated.

"Hi all. Next week we are having a whole new heat and AC unit installed in our house..."

"We are trying to save money, like everyone,.."

Have you considered a heat pump as your primary heating with the 80% gas furnace as back-up? If you're going to replace the outdoor a/c condenser and matching indoor coil anyway, a heat pump may be a smart choice depending on your utility rates.

What are your electric rates, natural gas rates?

Good luck.

Your furnace could be overisized for your house. I'm in Philadelphia area w/ 2500 sq ft 2 story home.

Just replaced 20 year 125,000 BTU furnace with 90,000 unit, which is a bit oversized, but needed the 4 ton blower.

Speaking of 4 ton; I hope that's a 2 stage unit. My heat gain needs a 3 1/2 ton unit, but I got a 2 stage 4 ton. It has rarely gone to 2nd stage, but gives long runs in first stage which does a great job on humidity (which you need). If not, hope you got a good thermostat that will allow humidity control (summer) with your vs blower.

Hope you got a heat calc.

V

Hi all. We are going to wait on the humidifier. We'll see how it feels this winter and if it's too dry, we'll install one later. THanks so much for the feedback on that, we really needed to hear what other people thought about it.

Garyg, thanks for the tip about the heat pump/gas furnace combo. We did consider it, but we had a straight heat pump a few homes ago and didn't care for it. It was a really cold winter and the electric bill was outrageous. Most importantly though, we didn't like how it felt. I'm one of those people who is always cold and I froze all winter, it just never felt warm enough. Thanks for the suggestion, though.

Veesubotee, I hope the system is not going to be oversized for our house. Is it inefficient to run if it is? any other down side? the company did send someone out to give me the estimate and they called in the numbers to the office for them to do the calculation. And yes, it is a 2 stage unit.

Not sure about the humdidity control on the thermostats, I will check into that.

thanks very much -

Did you happen to be standing next to him when he 'called in' the numbers.

Having done my own heat calc, I can tell you that there are a lot of numbers to be crunched: every wall measurement, every window measurement and accurate description of the type; insulation values, estimates of infiltration and general construction, etc. Would probably take about 15 minutes to convey that info, not to mention the time needed to compile that information.

Be advised that all 2 stage furnaces are NOT variable speed (blowers, that is). This is what's important for summer humidity control.

V

I

The TUD furnace model she listed in her post is V/S

R9V - Variable speed
5K - 5 t drive

Hi. Yes, the furnace is definitely variable speed.

As far as the load calculation goes, the guy giving us the estimate was here for a long time. He called numbers in to the office and then we waited for them to do calculations. At least 15 minutes. Then he gave us the 4 ton recommendation.

We will talk on Monday and I'll ask specifics about the "calculations" to be sure we are getting the correct size for our house. I was concerned about that. I had two other proposals from different companies. One was for a 3.5 ton system and the other a 4 ton.

Thanks for the advice. I do appreciate all the information I've gotten here.

the discomfort you felt with a heatpump is due to it's low heat output. however, a heat pump with a gas furnace as a secondary heat system is MUCH better. the heatpump basically runs only when it's warm enough to put out good heat, then the furnace fires up to put out heat when the heat pump output gets too low, and it totally shuts off the heat pump. this method of heating will save you thousands of dollars a year in heating bills. mostly in the transition temps of the day, and year. this way you don't run the costly gas when it's only cool outside. and you don't ever see cool vent temps when it's cold outside!

vstech - thousands of dollars? I live in NC (not terribly different than NoVa), have an 80% gas furnace, and spend under $1000 per year in gas in a 2800 sq feet 1.5 story built in 1993. My worst month was $200 so it is actually closer to $500 a year - and that is including hot water and cooking. I've thought of upgrading the furnace but I'd probably save $100 a year - that is a pretty long payback.... Even if gas doubled...

Thanks all. Interesting information on humidity. Glad we are holding off on the humidifier.

And thanks for the info on heat pump/gas combo. Definitely something to consider, but I do think we'll probably go with all gas.

Appreciate the input!

That guy's an idiot and since been proven wrong (written in '97), take a look at ASHRAE 2007 guidelines.

Here's another article of many that addresses standard homes and unvented attics

Many people can't maintain 35-40% humidity in the winter for comfort, respitory assistance, furnishing and flooring protection without a humidifier.

Here is a link that might be useful: attic ventilation and health concerns

We have read many of the articles by Mr. Lstiburek and his colleagues. They seem to do a lot of field testing and research, some of it in conjunction with the US Department of Energy's Building America program. They seem to reference recent, credible, original research, and they seem to provide reasonable written reports of what they try, whether it works or not, and why that might be so. It is surprising how much of what we do has little basis in research.

We have never met Mr. Lstiburek, but we are grateful for his and his colleague's work. We believe our home is more comfortable as a result. We leave it to others to form their own opinions of Mr. Lstiburek and his work from the impressive variety of written, credible insights offered on his firm's website (see link below).

Here is a link that might be useful: building science.com provides objective, high-quality information

FWIW, for anyone concerned about humidity and mold, here is a direct link to Lstiburek & Co.'s Mold articles.

BTW, we learned a lot from reading Joe Lstiburek's articles, but I didn't mean to sound like we are plugging him. The name of the following link, like the name of the link in my post above, is taken from the www.BuildingScience.com website.

HTH

Here is a link that might be useful: Preventing Mold Problems

Mold is no doubt an issue and excessive humidity is often the cause, on the same level, insufficient RH in an average home is a damage causing, uncomfortable, possibly energy wasting result also.

My only response was your adamant answer, no humidifier. Unless they rebuilt their home and sealed their envelope, to advise them to not have a humidifier is like me telling you to lose weight. (I've never seen you)

The moisture produced in a house doesn't just disappear or burn up in the furnace. Most houses that are dry in the winter are leaking heated, humid air. Better to recognize low humidity as a signal to tighten the leaks in the shell and both stabilize humidity AND conserve the energy spent heating the air. Many suggest the best first step to improve energy efficiency is to tighten the envelope by sealing leaks and cracks.

We followed the advice at sites like BuildingScience.com, and tightened our house. Our winter humidity now stays around 35% just from showering, cooking, etc. If it were lower, we would first look again to improve the shell.

Also, we agree that no one should take our word for it. We referenced the Lstiburek article and web site so anyone interested can read from an authoritative source and form her own opinion.

"The moisture produced in a house doesn't just disappear or burn up in the furnace. Most houses that are dry in the winter are leaking heated, humid air."

Each situation is different. Depends on how much moisture is produced versus how much is consumed/leaked. I have the opposite situation: a tight house and use a heat pump for primary heating along with a woodburning fireplace insert. My heat is very dry and the moisture levels are low in the winter. I'll be installing a by-pass humidifier this year.

I have a hardwood floor with a heat pump and heat strips and with no humidifier if the temps drop very cold here in Missouri the humidity drops like a rock and wreaks havoc on my hardwood floor. There are many variables on if you need one, in my instance I do. I paid 300 installed for a General Aire unit.

we live in a very dry environment (RH in single digits) in the mountains of northern california. We use a wood stove as primary heat and hydronic radiators as secondary. We have no ducting and this is a new house. What is the best way to bring up humidity in our house.

Mikey your choices are self contained wall humidifiers either evaporative or steam. Steam units arenÂt too attractive and difficult to hide. Wall units require space and can have limited outputs unless supplied with hot water. Given the fact that you heat with wood, this may not be a viable or desired option.

Your best bet would be a free standing console humidifier with its own reservoir, fan, media belt and control. You can then store it away in the summer.

Growing up in a baseboard hydronic house, I remember ours so well, and it worked.

The link below shows location-specific recommendations for much of Virginia, the OP's location.

Although the link is for that "Mixed-Humid" region, "Section One" of the "Information Package" shows two maps, which define hygro-thermal regions throughout North America based on rainfall (annual precipitation) and temperature.

A recurring theme at BuildingScience.com is that our building codes do not account for the different environments across the country. This is an amazing site if you want to educate yourself so you can better participate in decisions. And if your contractor is open-minded (as ours was), you both might be more satisfied with the result.

Cheers!

Here is a link that might be useful: Designs that Work: Mixed-Humid Climate

Finally, this linked report summarizes controversies of and approaches to managing indoor relative humidity. FWIW.

Here is a link that might be useful: What relative humidity should I have in my home?

There you go a report that suggests not too high to cause damage and not too low for furnishings and comfort.

The earlier post of no/never doesn't apply to everyone across the board, many people in substantial heating climates will benefit from supplemental adding of humidity to their living space.

OP: "Our home is in Northern Virginia. Hot and humid in summer, not so humid in winter."

Many people recommend humidifiers for their own reasons, regardless of local conditions, moisture-related risks, thoughtful alternatives, or the limits of human perception.

This is our last post in this thread, and we will let others have the last word, if they wish. We do not make, or sell, or install, or service humidifiers, but having lived in Northern Virginia, all we recommend to the OP is.... "No! No humidifier," and Caveat emptor.