Lennox or Trane furnace- will it reduce humidity?

[hvnoac]

I'm looking into replacing my 20 year old gas furnace and would appreciate your advice. I live in Seattle in a 1 1/2 story brick house with mostly finished basement. There is no A/C.

I've been checking humidity recently- it reads 60-75% throughout the house. (Did not measure during winter/spring when basement smelled really moldy. Currently there is only a very faint "off" smell.)

I have gotten proposals from several HVAC contractors. They propose either Lennox G71 or Trane XC95.

During times when heat is not needed, will running either of these furnaces in fan-only mode help with humidity?

I was told that the Trane XC95 can be programmed to run the fan intermittently. (This is why it was recommended over the XV95 model.)

One of the Lennox dealers recommended running the fan 24/7.

Or is it better to look into portable dehumidifiers or other solutions?

Thanks for your help on this question and a previous post. (I was unable to post a followup.)

[sktn77a]

During times when heat is not needed, will running either of these furnaces in fan-only mode help with humidity?



Not unless you have an A/C or dehumidifier tied into the new system.

[hvnoac]

Thanks for the reply. So are there any reasons to get the Trane XC95 with its programmable fan function when there is no A/C or dehumidifier?

[sktn77a]

Well, there may be other reasons, but dehumidification isn't one of them. Either of the furnaces should qualify the residential energy tax credit and possibly other rebates, depending on the model and where you are located.

[RyanHughes]

Define programmed fan function. Some thermostats (or at least the Honeywell 8000) have a circulate feature which runs the fan "intermittently" 30% of the time when there is no heating or cooling call.

[hvnoac]

I was told that the Trane XL900 thermostat that works with the Trane XC95 furnace can be set to run the fan intermittently without heat (or A/C), while the Trane XC95 only has a fan switch on the furnace itself.

I don't know how the fan operates on the Lennox G71, but running it 24/7 was recommended by one of the contractors. Different thermostats were recommended on the 2 Lennox proposals. (One recommended wireless.)

[RyanHughes]

The XL900 is built off the VisionPRO IAQ thermostat (step above the VisionPRO 8000), so the fan circ. feature makes sense. Doesn't mean the XC95 is necessary, but probably nice to have over the XV95 if upgrade price isn't necessary. The XV95 can be used with the 8000 thermostat and have the same fan capabilities (i.e., 30% runtime when not in heat or a/c cycle). Running the fan isn't going to help your indoor humidity concerns, however.

[hvnoac]

Thanks for the info. I had been impressed with the Trane dealer's attention to details, so I'm surprised that the upgrade to XC95 is not *required* to run a fan via the thermostat. We had specifically talked about flipping a switch on the XV95 furnace itself, which seemed inconvenient. Maybe other details were confused by him or by me.

Would running a furnace fan 24/7 along with a portable dehumidifier in the basement make any difference in the rest of the house?

[t527ed]

any fan on any furnace can be set for intermitant operation with the right thermostat.

running the fan might make a very small difference while running a dehumidifier but i doubt it will be much.

dry air around the dehumidifier will pull the moist air into it all by itself.