"Cast iron steam radiators under windows are rare in all but the smallest of rooms..." What? I grew up in a town where many of the houses were heated with steam, including my house. IIRC 17 steam radiators, added well AFTER the house was built, and every one of them was located under the windows. The same was the case in the homes of my friends. The house my Mother lives in right now was originally built with gravity hot air, but around 1912 was converted to gravity hot water. All of the radiators are located under the windows. Steam radiators don't solely rely on height to delivery heat. Just as with hot water radiators, steam radiators can be made shorter and longer to increase the radiation surface. The radiator under the bank of windows in the dining room was 24 sections, height was about 30 inches. I'll stick by my original assessment -- unless the owner is willing to put a rather massive amount of money into an old home -- totally new systems, insulation, windows -- a simple switch from steam to forced air doesn't make much sense. That may, or may well not, be appropriate, feasible, and possible. I'm certain, though, that if you do have 40 years of experience in this that you'd know there's often a point of no return where spending money to make upgrades is not only a waste of money, it's foolish.

Niabiaxxmoi, Upkeep on a ground-source heat pump is going to be a lot higher than on a gas furnace/air-air AC combo. A furnace has much lower complexity and higher economies of scale of manufacture. Note that zoning is not something that will save much money in a well insulated and sealed home compared to a poorer structure. I am going to disagree on some points. It is better to knock on doors than place flyers; ask any professional community organizer. Best to do both door to door and flyers. Just be sure to have a woman in the mix for door-knocking. Other women are much more apt to open up for a woman than a man if they are alone. Stay away from the mailboxes. Some mean-spirited person may rat you out to the Postal Dept. No, they won’t send you to Gitmo, but the max fine is the postage that you’d use to mail the flyers. Take into account the difficulty of an added flue pipe for an added gas water heater when counting your chickens. It should not be a problem, but on rare properties, it can be. OFF TOPIC WARNING: This may be splitting hairs in some views, but New York State does not have property tax. All property tax is local and it is not particularly high in New York State (I.e. the real New York.) National average property is about 1.3%. There are lots to quibble with in these numbers since there are so many exemptions and technical differences. According to my information, New York City and fellow travelers in the far Southeast (the other New York) has a very low property tax expressed on a % basis. That is part of the reason they must constantly siphon off revenue from the rest of the state to support themselves. They have a tiered system for residential properties. Adjusting for other vagaries, the rate varies from 0.6% in Brooklyn to 0.8% in NYC. I believe that is for homes with 1-3 families. If there are 4 or more residences in a building, the rate skyrockets. By contrast, in Monroe County, on the North coast of New York, the effective tax rate is more like 3%. In Rochester, more than half the property tax goes to public schools. Of course the assessed value of the property plays heavily into the actual dollar amount that you pay.

If you have 35000 btu from the outdoor unit...it means you can installed 2 indoor with 12000 btu and 1 indoor unit with 9000 btu. https://www.minisplitwarehouse.com/ The Benefits of Zoned Heating and Air Conditioning. If properly installed and designed by a home heating and cooling professional, zoned heating and air conditioning can dramatically increase your comfort and energy efficiency. 1.) Energy Savings When combined with programmable thermostats and Energy Saver mode, you can save up to 35% on your energy costs. By only having to produce a certain amount of conditioned air for the different “zones,” your HVAC system won’t have to work as hard. 2.) Easily Integrated Zoned heating and air conditioning can easily be integrated with your current system. Ductless mini-split systems can also be used for your zoned heating and air conditioning — no ducts required. Keep in mind, however, that for multi-zone applications, you will need to use an outside heat pump. 3.) Improved Comfort and Control Zoned heating and air conditioning are as simple or sophisticated that you want it to be. You can use your programmable thermostat and smartphone apps to have complete control of your home, or you can simply change the temperature manually. Regardless, by being able to change the temperature of each zone, you will have more control and comfort than ever without having to disturb other household members. 4.) Works for Both Heating & Cooling Zoned heating and cooling is a convenient and efficient solution for homes with multiple levels, sprawling designs, and large open areas that formerly relied on supplemental heating and cooling methods.

"In terms of the Bosch I doubt it would make much difference if you sized it for heating... unless you needed more heat than a 5 ton unit can produce." Name plate capacity of a heat pump refers to cooling mode only. The term "ton" refers to a ton of refrigeration which is 12,000 BTU/hr. Heating capacity is usually referred to in BTU/hr. The heating capacity of a heat pump declines as a function of decreasing temperature, so it can't be labelled without defining the outdoor conditions. Stated otherwise, a 5 ton heat pump does not have the same heating capacity as a 60,000 BTU/hr furnace--the capacity of which is independent of outdoor conditions. "However, the Bosch can deliver heat down to 5F." That statement can be a bit misleading. While a particular heat pump may be able to extract useful heat down to 5F, that doesn't guarantee it will be able to do so at a sufficient rate to meet the required heating demand without supplemental (backup) heating e.g., electric resistance heat strips. When evaluating a heat pump in heating mode, we're interested in determining the balance point--the outdoor temperature at which the heating load of the home and heating capacity of the system are equal. Below that temperature supplemental heating will be required. For most heat pump systems and most homes (excluding uninsulated homes and super-insulated homes) the balance point usually falls in the 30 F to 35 F range. To be clear, that doesn't mean a particular heat pump won't extract useful heat below that temperature---it just means the amount of heat won't be sufficient to meet the total heating load required and backup heat will be needed. I suggest you consult with an HVAC design professional who can calculate the heating and cooling loads for your particular home and your particular climate zone. Those can be used to select the appropriate equipment and to design the duct work if you elect to go with a ducted system. And, for what it's worth, mike_home has been a contributor to this forum for a number of years. In general, his posts suggest that he knows what he doesn't know. That's more than I can say for some "professionals" here on houzz.com