All residential models are energy star qualified and utilizes pvc venting.
Condensing boiler with on demand water heater.
The first one we would like to recommend is the takagi natural gas tankless water heater it is actually a commercial tankless water heater the flow rate reaches as high as 10 gallons per minute.
The water that goes through the pipes is heated and then it s ready for use.
Also idk of any single on demand water heater that would be able to handle the gpm needed for a car wash type shower.
Tankless water heaters work very simply.
It uses a unique microprocessor electronic control module that automatically adjusts blower speed and gas flow rate to closely match the boiler output for space heating or domestic hot water demand.
Indoor residential condensing natural gas combination boiler with 199 900 btu h input modulating.
M series natural gas condensing boiler tankless water heater with 160 000 btu input.
Condensing water heaters are a newer innovation in tankless water heater technology that claims to offer multiple promising benefits that increase efficiency as well as the durability of the heater.
Overall efficiency in a condensing model is approximately 90 percent which makes them one of the most efficient choices you can make.
This means cheaper materials can be used for the ventilation system.
The proline xe combi boiler provides industry leading continuous hot water delivery with its on demand high efficiency design.
The prestige is a 95 afue fully modulating stainless steel wall mounted condensing boiler.
Condensing water heaters pull heat from the exhaust cooling it to much lower temperatures.
The heating exchangers for condensing are made of stainless steel which is highly corrosion resistant and has a long service life much energy and wasted gas are saved because of the design.
I think you best option would be to use a small mod con boiler that has a 10 to 1 turn down with an indirect water heater connected to it that has enough storage capacity for the shower.
Proline xe condensing tankless water heater family state s condensing tankless gas water heaters are available in residential and commercial line ranging from 120 000 btu h to 199 000 btu h with options for natural gas and propane.
All at the same time.
Superior space heating performance the proline xe combi boiler offers up to 74 more heating capacity than other combination boilers.
Provides homeowners with an endless supply of hot water energy savings a space saving design and environmental benefits takagi and rinnai offers ease of installation now with more venting options right out of the box.
Condensing gas tankless water heaters delivers high efficent hot water in the same small box of regular efficent on demand water heaters.