How To Mount a Water To Air Heat Exchanger to a Plenum - Pt 2

[@KellyBurnham]

Hey Jeff, Good video and thanks for the tip on crimping the sheet metal around the coil flanges. One comment about the supply/return connection locations - the HW connections 'must be counterflow' (supply in the top) to get the maximum heat out of the boiler water. I have witnessed this on commercial projects with big air handlers and you will see a loss of anywhere from 10% to as much as 20% with concurrent flow. Thanks,

[@patrickrussell6684]

Jeff you showed how to establish the wood boiler to the gas furnace and using the aquastat. How do you wire the aquastat to the gas furnace? I'm assuming I'm using the wires from the aquastat to to tie into the thermostat in the house. Do I splice the wires and then connect to gas furnace?

[@FinkFarm2011]

Any suggestions or videos on mounting in a heat pump duct board plenum and using the hot water coil as a backup/below 40°. It’d be connected to a boiler.

[@andrewspiterie]

Hii Jeff , SummerAire handler TC3550E hot water is designed fed into top of coil and grundfoss pump pulling from bottom. Looks like a design flaw to me. After nine years running I want to reverse to the pipe connections to the handler and rotate the circ pump 180 degrees. I even want to add another hot water pipe to the input to reduce resistance and maybe get more flow. My water heater is a Rinnai tankless RC98. All good but could be better!? What do you think?

[@bobbrua8758]

could you stack 2heat exchangers one on top of the other to heat a large area? like your videos excellent quality thanx bob here

[@kennethrea79]

Will this heat exchanger work with hot water heater. Can’t use wood boiler where I live, and house is on a slab foundation

[@JoshDurston]

Your hot water (supply) should be on the leaving air side so the coldest water touches the coldest air and vice versa. This will give you a measurable boost in coil capacity. I suppose if your water is hot enough it doesn't matter, but in the world of modcon boilers, and ground source heatpumps I think it makes sense to design for lower temps when possible. Air is best handled by pumping away (from the boiler), using a proper air separator (between boiler and pump) with coalescing media to capture micro bubbles, and some strategically located air vents, bleeds, and a hand valve / pump arrangement that allows enough flow velocity to carry any trapped air out and thru the air separator.

[@jmonheim1203]

what happens if I cant find an exchanger to match my plenum

[@kennethwilliams2738]

what is the warmed water being used for? water has a high specific heat, if this heats the water a significant degree it is taking a lot of heat off the furnace, and possibly adding a lot of heat load to a system that was designed and sized to heat air.... is it being used to decrease Delta T and load on a water heater?

[@MrRaul1102]

Kenneth Williams

[@waldo15061]

You've got it backwards.. The water in the heat exchanger is being heated by a water heater or boiler and shedding heat into the air passing over it to heat the house.

[@richardbarber4444]

So I have successfully installed Water to Air heat exchanger of recommended size and find heat output inadequate. Air temp. is much lower than when oil burner is running even when water is at 180 F It seems to me that this arrangement is inherently less effective than the original oil burner system due to higher operating temp. of oil heater. Also, the heat exchanger increases the resistance to system air flow necessitating a higher fan speed, if this is possible. What measures must I adopt to remedy these issues?

[@JoshDurston]

Make sure your hot supply water is piped into the leaving air side of the coil. You want what's called crossflow for maximum heat exchange. Google crossflow in heat exchangers to see what I mean. This will maximize heat transfer and will give more than a double digit percent improvement in capacity for the same water temperature(unless you are already grossly over pumping the coil). Measure your temperature delta on both water and air, if your water delta is excessive (probably greater than 20-30F) you may under pumping. Anything that blocks the airflow (AC coil or hot water coil) will add resistance and may require a higher fan speed to move the same amount of air. ECM fans may adapt automatically. Air leaks will kill performance.

[@Superduty_59]

Jeff I have a manufactured home with a down draft LP furnace and I have an A-coil for the central air. From other things that I have read it says to install the heat exchanger under the a-coil. Do have any tips or advice for this type of install? The furnace is in a tight spot. Washer and dryer on the right and a little cubby hole fot the water heater to the left of the furnace. Thanks

[@gregmcbride471]

I have the same problem as you. What did you do to install your heat exchanger

[@Feedback4Utoday]

Interested in idea... But a lot of talk about fitting cardboard around metal... w%o actually saying anything... No idea what u r doing