High-Efficiency Home Gas Furnace & Susceptability to RFI

[W2XR]

The air-to-air unit is discontinued.....sounds like GFZd needs one.

Frank your house is too air tight and you are adding more insulation?
Ct. winters get cold but ya gotta breathe.
Fred

There was a study done several years ago by the Univ. of Minnesota concerning the optimum level of humidity within a home, vs. the potential for moisture/condensation damage to the structure, such as water-soaked insulation, rotting exterior sheathing, mold within the home, etc. At outside ambient temperatures of something like 30 to 40 degrees F, the maximum relative humidity within the dwelling should not exceed 40%. As the outside temperature drops below 30 degrees F, the level of the humidity within the dwelling must drop accordingly, so that at some very cold outside air temperature (see the results of the study), the maximum humidity within the home should not exceed 20%. That's pretty dry.

Otherwise, with tightly sealed home construction, you very much run the risk of the so-called "sick home syndrome", including not only moisture damage, but possible health hazards associated with the various pollutents within the home, including formaldahyde (used in some building materials) and a slew of other toxins. One established remedy for the this, particularly with homes so tightly sealed that air infiltration losses are significantly minimized, is the use of a heat recovery ventilation system, or HERV. These are essentially very efficient heat exchanger units that bring in the outside air, pre-heat it from the furnace to reduce the delta T losses, and replace the stale air within the home.  I'm installing one of these at the same time that I replace the furnace unit.

Residential HVAC technology has come a long way in the past 15 years or so, largely motivated by the need to conserve energy, along with the way that modern homes are built. Take a look sometime at the Canadian R-2000 standard for new home construction. And to build a highly energy efficient home that is inexpensive to heat and cool does not materially add to the price of construction.

73,

Bruce

[W1ATR]

Hiya Bruce. Gotta keep it short, but the 98v is a good furnace. Zero problems with them in the field except for some igniter failures which were an easy fix. The expensive stuff (blower motor, board, etc) is covered by a 10yr warranty so make sure you use a decent lennox dealer that will be around when you need them. If your electric bills aren't too bad now, then consider installing a hybrid system (swap your condensor for a heat pump) and set the changeover to switch it out around 33deg. A manual D ductwork calc is important to make sure the 98 is going to run at it's rated efficiency. Too many of them are installed on pissweak ductwork and the gas bills actually go higher than a 90% would use. (Or even an 80% in some cases I've seen.) The heat exchanger has a lifetime warranty on it, BUT there can be problems with a claim if the ductwork isn't up to snuff and theres a failure. Stay away from pleated filters unless its one of the bigger 'air bears', otherwise just spring for an electrostatic. This furnace is all about proper airflow.

The thermostat should be what lennox offers for the system, but you can use any two stage stat and set the high low off settings with dip switches on the board. The lennox stat is better in a few different ways however. This is good info to know should it die and another isn't immediately available, (like at 2am in Feb) then a regular two stage stat can be slapped on the wall temporarily.

As far as the house being too tight, a lot of people don't quite grasp how severe it can really get with barely any signs until it's too late. There was a family around here, maybe Mass, I don't remember, but they gave themselves some sort of weird blood poisoning (I think a kid didn't make it) from indoor air pollution from cooking, candles, cloths drier, etc, in a house that was too tight. As Rob suggested, all you guys that like insulation and weather proofing just a little too much really REALLY need to invest in a fresh air exchanger. Frank, if your getting headaches during sleep (When your brain and body needs clean O2 the most) and you have to crack a window, the indoor O2 levels in your house are already way too low.

Good luck with the new install Bruce.       

[W2XR]

Hiya Bruce. Gotta keep it short, but the 98v is a good furnace. Zero problems with them in the field except for some igniter failures which were an easy fix. The expensive stuff (blower motor, board, etc) is covered by a 10yr warranty so make sure you use a decent lennox dealer that will be around when you need them. If your electric bills aren't too bad now, then consider installing a hybrid system (swap your condensor for a heat pump) and set the changeover to switch it out around 33deg. A manual D ductwork calc is important to make sure the 98 is going to run at it's rated efficiency. Too many of them are installed on pissweak ductwork and the gas bills actually go higher than a 90% would use. (Or even an 80% in some cases I've seen.) The heat exchanger has a lifetime warranty on it, BUT there can be problems with a claim if the ductwork isn't up to snuff and theres a failure. Stay away from pleated filters unless its one of the bigger 'air bears', otherwise just spring for an electrostatic. This furnace is all about proper airflow.

The thermostat should be what lennox offers for the system, but you can use any two stage stat and set the high low off settings with dip switches on the board. The lennox stat is better in a few different ways however. This is good info to know should it die and another isn't immediately available, (like at 2am in Feb) then a regular two stage stat can be slapped on the wall temporarily.

As far as the house being too tight, a lot of people don't quite grasp how severe it can really get with barely any signs until it's too late. There was a family around here, maybe Mass, I don't remember, but they gave themselves some sort of weird blood poisoning (I think a kid didn't make it) from indoor air pollution from cooking, candles, cloths drier, etc, in a house that was too tight. As Rob suggested, all you guys that like insulation and weather proofing just a little too much really REALLY need to invest in a fresh air exchanger. Frank, if your getting headaches during sleep (When your brain and body needs clean O2 the most) and you have to crack a window, the indoor O2 levels in your house are already way too low.

Good luck with the new install Bruce.       

Hi Jared!

Thanks for the great input here. If anyone knows this stuff, it's you, and I was hoping you would respond.

Very interesting about the ductwork, as none of the HVAC contractors I met with have brought that up............I'll have to look into this.

Can I call you at a convenient time to discuss this in greater detail? Plus I'd like to speak with you about another (unrelated) topic as well.

I may have misplaced your phone number. Can you advise via PM your phone number and a convenient time for me to call? My e-mail is triodes@optonline.net

Looking forward to your reply.

73,

Bruce