Under-performing furnace and upgrade/mod. to the ducting.
Sept 14, 2016 12:25:42 GMT -5
michael79 likes this
Post by myredracer on Sept 14, 2016 12:25:42 GMT -5
First, apologies for the large photos and the space they take up. Can't find a way to make them smaller on this forum.
From the day we picked up our new Spree 262RKS 2 1/2 years ago, the furnace had trouble keeping the interior warm in cold weather. Once it got below 40F, it just wasn't warm enough and the furnace would run non-stop overnight when the outside temp. dropped. It was cold in the bedroom and we needed extra covers. We took it to the dealer who said it was the sail switch and they installed a new one - no improvement. The factory hacked a big hole in the subfloor for the ducting about 10"x10" next to the furnace. I could feel the draft coming up from below and could see the ground below around a hole for the propane line. With the hole being right next to the furnace, some of the return air was coming up from the underbelly space and cold outside air was being drawn into the furnace instead of interior air. For the 2014 262RKS model, the factory ran a 4" flex duct under the subfloor and over about 5' to an outlet in the kitchen area. The duct was non-insulated and it sat on top of the coroplast which had no insulation so the duct was sitting right on top of a cold surface.
It was also partially collapsed where it went through a floor joist thus restricting flow.
I sealed up the hole in the subfloor with plywood and replaced the flex duct with insulated duct. Pic #1 shows the hole in the floor. I had previously tidied up the wiring rat's nest for electric heaters I installed. Pic #2 shows the 8' long 4" flexible semi-rigid aluminum duct I used and the commercial duct insulation I wrapped around it. Pic #3 shows the modification I did to the original heat outlet in the kitchen. The black thing beside the duct is a built-in vaccum unit. Because I had to make a 90 degree bend and make clearance for the drawer under the dinette seat, I used a bend with an oval cross-section on one end. These are used in wood-frame bldg. construction. Pic #4 is the original factory flex ducting beside the furnace. Pic #5 shows the modified ducting and patched hole in the floor. I sealed up any gaps around the new ducting. Getting the new 4" duct under the floor and from the furnace over to the grill on the back of the opposite dinette seat was not easy because I did the work from inside above the floor and I had to get an arm way under the floor to fish the duct between the webbing in a floor joist.
While doing this work, I also changed the 2" ducting to the bedroom to 4" because the bedroom was so much colder than elsewhere. The 2" bathroom duct originally ran all the way under the shower to below the sink and was unnecessarily long and reduced flow. I rerouted it to beside the toilet. I also went through the entire TT and sealed up any other holes I could find through the floor.
When all done, all I can say is WOW. What an unbelievable improvement. Instead of taking hours to get comfortably warm, it's now more like minutes. Warm air now comes blasting into the kitchen and same with the bedroom. I installed a new grill in the bedroom that has a damper so can control the heat output as needed.
Gil, Deb and Dougal the Springer Spaniel
2014 KZ Spree 262RKS
2009 F250
From the day we picked up our new Spree 262RKS 2 1/2 years ago, the furnace had trouble keeping the interior warm in cold weather. Once it got below 40F, it just wasn't warm enough and the furnace would run non-stop overnight when the outside temp. dropped. It was cold in the bedroom and we needed extra covers. We took it to the dealer who said it was the sail switch and they installed a new one - no improvement. The factory hacked a big hole in the subfloor for the ducting about 10"x10" next to the furnace. I could feel the draft coming up from below and could see the ground below around a hole for the propane line. With the hole being right next to the furnace, some of the return air was coming up from the underbelly space and cold outside air was being drawn into the furnace instead of interior air. For the 2014 262RKS model, the factory ran a 4" flex duct under the subfloor and over about 5' to an outlet in the kitchen area. The duct was non-insulated and it sat on top of the coroplast which had no insulation so the duct was sitting right on top of a cold surface.
It was also partially collapsed where it went through a floor joist thus restricting flow.
I sealed up the hole in the subfloor with plywood and replaced the flex duct with insulated duct. Pic #1 shows the hole in the floor. I had previously tidied up the wiring rat's nest for electric heaters I installed. Pic #2 shows the 8' long 4" flexible semi-rigid aluminum duct I used and the commercial duct insulation I wrapped around it. Pic #3 shows the modification I did to the original heat outlet in the kitchen. The black thing beside the duct is a built-in vaccum unit. Because I had to make a 90 degree bend and make clearance for the drawer under the dinette seat, I used a bend with an oval cross-section on one end. These are used in wood-frame bldg. construction. Pic #4 is the original factory flex ducting beside the furnace. Pic #5 shows the modified ducting and patched hole in the floor. I sealed up any gaps around the new ducting. Getting the new 4" duct under the floor and from the furnace over to the grill on the back of the opposite dinette seat was not easy because I did the work from inside above the floor and I had to get an arm way under the floor to fish the duct between the webbing in a floor joist.
While doing this work, I also changed the 2" ducting to the bedroom to 4" because the bedroom was so much colder than elsewhere. The 2" bathroom duct originally ran all the way under the shower to below the sink and was unnecessarily long and reduced flow. I rerouted it to beside the toilet. I also went through the entire TT and sealed up any other holes I could find through the floor.
When all done, all I can say is WOW. What an unbelievable improvement. Instead of taking hours to get comfortably warm, it's now more like minutes. Warm air now comes blasting into the kitchen and same with the bedroom. I installed a new grill in the bedroom that has a damper so can control the heat output as needed.
Gil, Deb and Dougal the Springer Spaniel
2014 KZ Spree 262RKS
2009 F250
