Aprilaire - 720M

Thank you! I purchased a 720M. I found a wiring diagram on setting it up with a smart thermostat so I didn't need the more expensive 720A.

Tbh, I'd return and get an Aprilaire AA720M, install it above the cased coil on the supply. Call it a day. Bypass humidifers are not recommended on two stage and modulating furnaces. Given you got a Dave lennox signature series/elite series I know it's got a constant cfm motor, and I know your just going to waste lots of water. AA720M uses an internal fan and mounts like the bypass. 24vac to the Lennox board to be used by icomfort. While it has a 120v outlet plug for the fan. Internal circulator and powered by hot water means best price/performance you can get.

A bypass humidifer relies on the furnace fan blowing heat over the evaporator pad to humidify the air. The less air and heat you have, the less effective the humidifer is. The Lennox SLP99V is a modulating furnace, so it runs at very low speeds for most of its life. This means you wouldn't get enough hot air to get full use out of a bypass humidifer. The AA720A has an internal fan and it's installed on the supply side, so it eliminates the issues with pairing a bypass to a constant cfm furnace.

600 is a bypass air humidifier. 720 is fan powered. 800 is steam. 720 is 60% more water efficent over 600 model, has an easy to change hydrocore, and is better performing. While having no performance drop on 2 stage and variable speed furnaces. I'd go 720

Ive never heard of a single stage A/C that can't be paired to a two stage or modulating furnace before. Blower speed for the furnace heating will be variable, however for A/C cooling it will be a single constant airflow speed. To be honest with your current configuration the 600 will do just fine. However if you are considering a two stage model, which I will highly recommend, it should be paired to a 720 series.

What a silly contractor. Very silly. Lennox doesnt make anything that locks you into a single stage furnace. You dont go two stage or modulating to save gas. You do it to reduce noise, get better temperature distribution, more even heat across the home, with a gentler temperature curve. Plus it significantly reduces start/stop wear and tear, so its as reliable or more reliable compared to single stage. My company may install a couple hundred furnaces a year. 90% of those furnaces are two stage models. 7% modulating, and maybe 3% single stage. A two stage model really is not much more than a single stage, and boasts significantly better comfort features. I've never had a customer in my entire career regret upgrading.

EXACTLY what I did. I just finished my install a day ago. In rearching my setup, I realized I could get and insstall a 720M (and NOT the 720A) and just hook the bugger up to my NEST thermostat. I however had the fun extra task of rewiring my thermostat wire; my furnace (2-stage, with A/C) uses 6 wires, and that's EXACTLY what the stupid hvac guy installed when the furnace was replaced a year ago. Had I been home when he did it, I would have asked for more wire. So, I ripped out the 18/6 thermostat wire and replaed it with 18/8. With the extra wire now available I hooked that to my "\*" terminal on the NEST and I was good to go. Works like a charm, and frankly,wiring in a smart thermostat to that humidifier was way EASIER than using Aprilaire's humidistat and transformer combo.

Weve installed a bunch of 720's since we swapped to them about two months ago. I think it's a better design than the 700, less waste, better blower design. How they hold up remains to be seen. I don't hate the hydro core idea, a lot of 700's should have been getting a new pad holder frequently that weren't and this will take some issues out of the equation. Hydrocore cost is 34.99 and it's way easier for a homeowner to change than on a 700. A generic pad from Lowe's for a 700 was still 12.99, cost difference is not that high.

720 piped to hot water will probably keep up, otherwise get a steam humidifier if you're really worried about it.

I just installed the Aprilaire 720 last weekend, easy as pie!

See if you can open the duct to the upstairs bedroom. Ductless would be a potential solution, but personally I prefer ducted. You may need to add some ductwork to accommodate a ducted heat pump. If the unit is properly sized, it should dehumidify in the summer ok (although in the shoulder season, running a dedicated dehumidifier may be necessary). A central humidifier during the winter is recommended. The heat pump shouldn't take as much humidity out of the air as the oil furnace does, but will likely still need help. I used the Aprilaire 720 and it raises the humidity enough to be comfortable. But you may need a steam based humidifier like the Aprilaire 800 if the 720 isn't enough. Steam is more expensive to install and run, so I hesitate to recommend it.

Depends on what brands your getting quoted aprilaire is the king here and most others I've seen tend to junk out after a few years that's a fair price for the work being done

Aprilaire whole home system is the way to go…

Mines worked flawless with basic maintenance for 5 years strong so🤷‍♂️

And no one cut any wires, it was an easy install along with a new blower and heating coil being installed at that same time.

Get a quote from Buric! They did our HVAC replacement a few years ago and we added an AprilAire humidifier at that time. They were great and other family have used them since and also had good things to say.

That system is a piece of shit. Just Google the reviews or look on YouTube. Not only is it a piece of shit but they designed it so if you have it installed they will cut out your wires and you will not be able to replace it with a normal thermostat without getting expensive wires repulled through your walls.

The system uses a proprietary control panel with a touch screen that is not connect with the standard set of wires. They most definitely did cut the wires to interface the control panel at your furnace/air handler. There is no other way to wire it. Google install Aprilaire. They have a YT showing you exactly that.