I know it has been years since this thread has been active but I got a NZ26 installed earlier this year and we have been using it to heat our 2 story 1850 sq/ft house and I wanted to share my experience. I just want to say there is no right unit for everyone and for every square footage.
If you are buying a fireplace unit to heat the whole house (like I got mine for), then I recommend over sizing the unit by a little bit but not much more. If you oversize the unit too much, you are going to burn a lot of extra wood just to heat up the cast iron fireplace which takes a lot of wood to heat up the fireplace. These kinds of fireplaces are only going to start heating your house once they heat up. The hot fireplace is what heats your house, not the wood burning inside of it. A huge unit will take a lot of wood to heat up and then it will be blasting in so much heat that you and your family will be baking. In addition, if you put a smaller amount of wood into a huge unit, it will take forever to heat up. In other words, if you are getting your unit to heat your house, size the unit you get to the size of your house... maybe go a little higher but not too much higher.
Our fireplace comes with a glass window door that is easily removed for cleaning. I take the door off and lay it on the floor and spritz some fireplace glass cleaner on it and let it soak on the brown stains for a while. Then, most of the stains remove easily without lots of elbow grease. It is very easy to put the door back on. Taking the door off and on is as easy as using a hanger on a bar (just a heavier hanger). You can clean the door without removing it but it is much easier to clean if you remove the door and lay it down on a table or the floor. Then, when you use a paper towel, you can put your body weight into cleaning the glass.
They have a steel drawer inside the unit that is used for collecting ash. It can hold a couple days worth of ash. This drawer is great because when the ash builds up high in the fireplace, I don't need an ash can. I just plop the ash from the fireplace into the drawer and let it sit there for a day and then throw it out in the trash the next day. I thought I was going to have to buy a metal container for this but it came with the unit and it is inside the unit and you can't see it from the outside.
When you start the fire in the unit, it takes a good hour for it to heat up before it really starts heating the house. So, when you first have it installed and you light a fire and it is not giving off any heat, don't worry. Be patient. The unit has lots of thermal mass and gives off heat well after the fire has burned out.
Since we have a 2nd story and since the bedrooms are upstairs, we had an optional gravity vent installed. This is very useful for early morning. You can open or close the vent. I usually keep it shut so that the first floor builds up with heat and it slowly rises upstairs. But, when you want to blast the upstairs with heat, I get up early sometimes before everyone else in the family and load up the fireplace with wood and open the vent and the heat pours into the upstairs. It gets nice a toasty and the wife and kids have an easier time getting up because they are not hiding under the warm covers to avoid the cooler air of the house.
There is a lever that controls the rate of air flow into the unit. This thing really has a huge affect on the rate at which the wood burns. What I do is a burn normal sized logs normally (the smaller the log, the more heat it gives off and the faster it burns) but at the end of the night, I throw a big boy log into the unit and set the air flow really low. I've put in logs that take up almost the whole fireplace. This way, it burns slow all night long.
It comes with an electric fan that kicks on and off according to how hot the unit is. You can shut the fan totally off if you like.
I love this fireplace. The reason I got it was because of Hurricane Sandy when the power was out here in NJ for a while. The house got cold. In addition, I am expecting the price of natural gas to go up. We are hoping to save over $1,000 a year on heating costs with this unit. Because we have a tall house, it cost about $17,000 for everything, including the hearth, stainless steel double walled chimney and the foundation and the soffet and the siding. They had to build everything new for us because we didn't have a fireplace before. In addition, I have wood logs delivered to my home by a tree service and I split wood all year round as a form of exercise. For a man, there is nothing like splitting wood that you are going to use to heat your house. You get to swing and axe and destroy, just like a little kid again, and at the same time, you are working out and doing something productive. I use an axe and sledge hammers and splitting wedges. When I first started, I wasn't strong. But, after a year of splitting logs, I can easily pick up the wife into my arms and walk around with her no problem. Hold her like a little baby. And I am a small guy, only 5'4" tall. If I tried that last year, I would have need a hernia surgery.
I am very happy that we got this NZ26 fireplace. It is an excellent product and I recommend it. It was installed by Home Conservation Energy out of Green Brook, NJ. I highly recommend them.
