glib: You might be right if the outside temperature were just below freezing or if the crop were more freeze hardy. But I'd bet a lot of money that my open blossoms would be frozen well before the water in the barrels froze. A couple nights ago when it was 10F outside and 55F inside I cut off the heater and fans to simulate a power outage. In 37 minutes the air temperature was down to 41F. In another 37 minutes or one hour at most the buds would be freezing. The heat is in the water but it just isn't going to transfer fast enough to protect something as tender as fruit buds. And the water in the barrels was at about 60F when I cut the power. Maybe under other conditions or with freeze hardy crops like greens, theory might hold up. I won't trust it at 10F outside for fruit bud protection. I do greatly appreciate your input and calculations. Maybe you are right. But is all that heat of freezing going to be released all that fast?

I have had a Bertazzoni 36" gas range with 5 burners for about 7 years now and I absolutely hate it. It replaced a 5 year old Thermador which kept breaking down. When it worked, the Thermador oven was fantastic and the temperature incredibly accurate. My Bertazzoni is quite the opposite: the oven temperature is not calibrated, unless I have a thermometer in the oven, I have no clue what the temp is, I cannot rely on the outside knob, it's inaccurate. My cakes are often burned on the outside and raw on the inside. The bottom of the oven has been curling up, it seems quite flimsy. The igniter broke twice and now, I cannot use the broil setting because it will not ignite. The top burners are ok, the largest one (2 part) is practical for very large pots (we are a large family, we often utilize larger pasta pots) but it still takes for ever for water to boil. Cleaning the burners is quite challenging, especially if liquids boil over. One of my oven lights burnt 2 years ago and no one was able to help me purchase a new one. Customer service at Bertazzoni suggested I go to a lighting shop for a bulb, they were not able to sell me a replacement one. I did just that and was told by 3 shops that they do not carry this type of light bulb. All in all, I would not recommend this gas range. I am now in the market for a new one, does anyone have any recommendations?

Capedude, you have started down the path that would be called a layman's explanation. My knowledge of the DHW and boiler standards is obviously limited. That said, I deal with various types of industrial standards now and then and I have learned to understand how they work. My read is that the boiler standards are fit to combination steam-hot water boilers. The water heater standards are more restricted to appliances that make hot water. Many, if not most, jurisdictions allow the installation of water heaters (Z21.10.3) to power hydronic heat. That means that many officials have decided that they area safe for that use. It boils (he he) down to the question of which set of standards is a better match to an hydronic (hot water) heating system? Is it a set of standards for appliances that make hot water on the one hand, or on the other hand, a set of standards for appliances that can make hot water or steam. If code-compliant, the Westinghouse or HTP Pioneer option makes for an inexpensive way to graft a very efficient boiler into an archaic system without the need to install additional piping (primary-secondary) for boiler protection. You have a buffer built in eliminating the need for a separate buffer tank to prevent short cycling in the case of small zones. The design of the heat exchangers in these water heaters is unique. it looks like they use the inherent stratification of how water in the tank to set up a counter-current exchanger. If you don't like the water heater aspect, a Versa boiler with Z21.13 can be installed if it is not too big and you can stand the additional coin. The physics of the HX are the same as with the water heater. Reports I have seen indicate that even though they may cost more than some other efficient boilers, the amount of money that you can save in repiping (buffer tank) and controls more than compensates for it.

Haha, well now this makes sense. I'm in Silicon Valley and have more than enough exposure to engineers and tech types who think they can understand and improve just about anything with homespun whizbang. They far too often fail but have trouble admitting that. Usually the damage isn't too costly. That may not be so here. JoeQ, your clever "system" may bring your furnace to a premature end of life. Or may have already. And that can lead to carbon monoxide emissions in your home. Or may have already. A new furnace may be a few thousand dollars. Health damage from carbon monoxide, hard to quantify. Your "system" isn't performing its most basic requirement, which is to properly control the furnace without damaging it or risking your health. Declare your experiment over and call an HVAC company to get your stuff working right, the traditional way. Good luck.