Humidifier question

[raharra]

Please remember that I am an electrician, so don't use big words/technical phrases or else I am going to have the "deer in the headlights" look.

Yesterday, I replaced a broken First Stage sequencer and two burnt jumper wires on a customer's electric furnace. He has problems with excessive humidity in his basement and he asked me why he required a humidifier on his furnace.
I told him that I would find the correct answer and get back to him.

For us ignorant wire-jockeys, why would an electric forced-air furnace require a humidifier? I thought that typically only gas furnaces would dry out the air enough to need to add humidity back in the air.

His next question was whether I can install a Programmable T-stat that will combine his humidistat & t-stat. Has anyone ever installed one before and where do you purchase it?

Thanks,
Rick

[trouble time]

You need a humidifier on your furnace to add moisture to the air in the winter. All furnaces dry the air out. A comfort level of 38%-55% humidity is desirable. Any heat source will dry out the air. Electric heat does a very good job of it. You do not need a humidifier in the summer just the opposite.
As for the thermostat/humidistat combo I do not know of one on the market.

[Gross]

ask him why the heck he has an electric furnace in nebraska....

[TalkingHead]

Think of humidity as being relative to temperature. For every one degree you raise the temperature and the moisture in the air stays the same the relative humidity goes down 2%. Regardless of the type of heating used in a house as the outside air leaks inside during the cold weather months it gets heated up. The amount of moisture stays relative the same as it was in that air outside, but now it is warmer and the relative humidity as a percentage goes down. That is why people in houses during the winter feel more comfortable adding humidity and that is why it is a good thing to seal up as many air leaks as practical. The average RH in the Sahara desert is 23%. You home can have less than that without adding humidity when it is cold outside.

[garya505]

In Nebraska, the humidifier should only run in the winter when the indoor air gets dry. In the summer he could probably even use a dehumidifier, at least in the basement.

There are several humidifiers in the market that can control a furnace and a humidifier. The one that is most popular here is the Honeywell VisionPRO, though several of the Honeywell and White-Rodgers thermostats will do it, as well as other brands. Unfortunately we can't post direct-purchase links here, but they're not difficult to find if you look. Don't bother with the "big box" stores like Homers and Lowes though.

[raharra]

Thanks for all the advice.

As far as why do we have electric furnaces in Nebraska, I could say that we just got electricity last week out here in the Boonies, someday we hope to get this Internet stuff that everybody is talking about. Up till this point we were still burning cow chips & sod grass. Pretty easy to troubeshoot a cow chip furnace.

The type of furnace that are installed in a residence depends on where you are located. If you are within city limits, you have the choice of Natural Gas or electric.
Out on the farms, the majority of them use Propane with a few older ones using electric heat. If the customer lost utility power for a couple of days, most farmers have some sort of generator and "double throw" disconnect so they can power up a few small appliances until they get utility power back. A propane furnace typically uses about 10 amps to keep the house from freezing up; well within the capacity of even a small generator.
If the customer has a big enough generator (usually driven off the Power Take Off of a tractor), he will be able to feed an electric furnace with a portion of the heaters turned off.
There are a few old units that burn fuel oil, but they are few and far between. Nobody likes the smell and the price is higher than other fuels.
We had a streak of "pump & dump" ground water based heat pumps with electric backup heat strips in a few new houses that we wired in the past 5 years, but I am pretty sure the initial install price scared most customers off.

That is pretty much the sum total of what I know about furnaces.
Rick

[garya505]

The payback on ground-source heat pumps is just too long. It sounds like out in the boonies there would be a great place for a dual-fuel system with a air-source heat pump and propane furnace (or electric strips if you really need to) for aux heat. Propane and electric furnaces are expensive to run. You'd need 30 to 40 Amps for the heat pump though, and maybe another 10 or so for the blower in the furnace. I'd probably just go to aux heat on the generator when the power fails, then you only need the 10A. Just like what they're doing now, but most of the time they could save a lot of money by running the heat pump. Air-source heat pumps have come a long way in the efficiency department in the last few years.

[trouble time]

Thanks for all the advice.

As far as why do we have electric furnaces in Nebraska, I could say that we just got electricity last week out here in the Boonies, someday we hope to get this Internet stuff that everybody is talking about. Up till this point we were still burning cow chips & sod grass. Pretty easy to troubeshoot a cow chip furnace.

The type of furnace that are installed in a residence depends on where you are located. If you are within city limits, you have the choice of Natural Gas or electric.
Out on the farms, the majority of them use Propane with a few older ones using electric heat. If the customer lost utility power for a couple of days, most farmers have some sort of generator and "double throw" disconnect so they can power up a few small appliances until they get utility power back. A propane furnace typically uses about 10 amps to keep the house from freezing up; well within the capacity of even a small generator.
If the customer has a big enough generator (usually driven off the Power Take Off of a tractor), he will be able to feed an electric furnace with a portion of the heaters turned off.
There are a few old units that burn fuel oil, but they are few and far between. Nobody likes the smell and the price is higher than other fuels.
We had a streak of "pump & dump" ground water based heat pumps with electric backup heat strips in a few new houses that we wired in the past 5 years, but I am pretty sure the initial install price scared most customers off.

That is pretty much the sum total of what I know about furnaces.
Rick

With humor like that you are going to fit in quite nicely here.