SpacePak Winter Supply Shut-Off

By Todd Fratzel on Air Conditioning, Maintanence

picture of SpacePak room terminator in ceilingWe use the SpacePak air conditioning in our new home to cool the house in the summer. The SpacePak system is only used for air conditioning so there are two steps to take each fall in preparation for winter. Because the SpacePak system is not used for heating the house it sits unused all winter. The problem with that is warm moist air can rise up into the supply ducts and the air return. That causes two problem; the first is a loss of warm air and the second is a condensation problem.

picture of SpacePak Room Terminator Winter Shut-OffObviously losing warm air up into the duct system isn’t a great idea especially with the cost of fuel to heat our home. The other problem is having the warm moist air rise up into the cold ducts and then condensing and causing water to drip back down into the house. In fact, I’ve seen houses that didn’t address this problem with a serious amount of water dripping out of the ducts on a really cold day.
picture of SpacePak room terminator with winter shut-off installed
SpacePak systems come with winter supply shut-offs for the room terminators (registers). The simple winter shut-off is really just a plug of sorts (see photo). It’s a simple metal disk with a round piece of felt attached to the back. When you push the shut-off up into the room terminator the felt helps create a nice snug / tight seal. The plug effectively seals off warm air from rising up into the duct system.

picture of SpacePak return air grill with insulation installedThe other big item is plugging the large air return. For this I use a piece of foil / bubble / insulation cut slightly larger than the air filter. By cutting it slightly larger it’s easy to push into the opening and have it stay in place without falling down. If you need a place to buy some Foil Insulation then Amazon has some that will work well. I also took the time to remove the EZ Kleen aluminum air filter and clean it. These filters can be cleaned with warm water. I just set them in the but and spray them down real good. This way everything is all set for next summer when the heat comes and we want to fire up the air conditioner.

So if you have a SpacePak air conditioning system and you live in a cold climate make sure you plug the room picture of EZ Kleen aluminum air filterterminators each winter. You’ll save money and possible damage to your home from dripping water.

If you don’t have central air then check out some information on a portable air conditioner.

About the author

Todd Fratzel

I'm full time builder for a large construction company in New Hampshire. I run their design-build division that specializes in custom homes, commercial design-build projects and sub-divisions. I'm also a licensed civil and structural engineer with extensive experience in civil and structural design and home construction. My hope is that I can share my experience in the home construction, home improvement and home renovation profession with other builders and home owners. I'm also the Editor-in-Chief and Founder of Tool Box Buzz. Please feel free to contact me if you have any questions, suggestions or you'd like to inquire about advertising on this site.

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  1. Rich Bonelli says:

    I’m considering Spacepak for my old home but I’m concerned about the potential noice issues with a high velocity system. What has your experience been? What about custum modifications such as zoning off areas off a single fan coil unit?

    • Todd says:

      Rich – I have SpacePak in my home and I don’t mind the noise level. It is slightly noisier than our previous home with a traditional system but not that bad.

      Most of the installers that we’ve used over the years for this system all say the same thing. Proper installation is key to minimizing the noise effects. What that ultimately means is being sure that supply lines have a nice straight shot through the ceiling or wall. Installers must avoid sharp bends in the supply line near the outlet.

      I’ve never been involved with a system that used zoning.

  2. Frank says:

    Hi Todd.

    We got our spacepak professionally installed this summer. 3 ton system and 15k later…I have a few questions if you might be able to help…

    We’ve had our air completely off for a while now and we’ve noticed when the nights are really cool like tonight and it’s a bit windy we hear these ‘heart beat’ like sounds coming from the attic spacepak with big wind sounds that come through the holes in the ceiling. You can feel cool air coming through the holes. As for the sounds, you hear them first and then the wind comes. I’m hoping plugging each register will help (assume I can purchase online somewhere?) with the air coming through. Will taking the filter out and putting foil insulation take care of the sounds? We have attic vent to help keep the attic cool when the system is running. I wonder if we need to somehow close that?

    Have you heard of similar issues? Appreciate any insight!

    • Todd Fratzel says:

      Frank – We’ve installed quite a few of these systems in houses we build and I have one in my own home. Because the vents are small diameter, they magnify sound from air movement. All duct systems get air movement from wind conditions, but this is magnified due to the small size ports.

      Your system should have come with “plugs” so you can plug the holes in the winter. This is VERY important for a couple reasons, one it stops condensation from happening in the lines, and two it stops cold air from circulating through the system and back into the house.

      I also use some foil faced “wrap” to plug the cold air return in the winter, again to stop air movement and more specifically heat loss.

      I haven’t “heard” that noise, but it seems reasonable with quite a bit of air movement.

  3. JG says:

    Hi, is there a better aesthetic than the “nipple” look for these plugs, or a flat removable insert to cover them? The only thing I do not like is the look of a nipple sticking out of the circular vent.

  4. Chad Derbyshire says:

    Hi, I have a question regarding these type of systems. Is there any device for closing off vents in rooms that we do not want the air to blow into? We have these ports in our spare bedroom, and closets, and want to plug them off, but I have not been able to find such a device. If we did, would it hurt the system?

    • Todd Fratzel says:

      Sometimes installers will put dampers in the attic so you can isolate areas. Other than that I’m not entirely sure. I highly doubt it will damage anything.

    • Dan says:

      Hi – just caught this post. I would like to close a couple of holes in basement rec room as it is not used very much. Will covering these basement holes force more air/greater velocity to 1st floor? this is our goal… thx!

  5. Nicole says:

    I want to direct the air in each room so that it flows into the room not down into the corners where the holes shoot it now. I cannot find any way to direct the air (such a plastic vent cover/directional you would see with a rectangular forced air vent). Ideas?

    • Todd Fratzel says:

      If it was designed correctly there’s no need to do that. I’ve NEVER seen it done in all the homes we’ve built.

  6. Nancy L. Miskowicz says:

    Where do you obtain the plugs to close off the vents of the space pac? I purchased my home one year ago and would like to plug the vents when cool weather arrives.

  7. Alex says:

    Thank you soooo much for this post! We inherited a SpacePak system in the house we bought. It would not be our choice for AC, but we can’t afford to replace it. For a couple of years now, we’ve had growing brown water spots around the outlets and condensation dripping down in the winter. This year has been particularly bad. Our AC repair guys had no idea what was causing it and, having no experience with SpacePaks before this, we had no clue either, until I stumbled on your post. I just ordered some winterizing plugs and will head out to buy some reflectix to plug the air return. Hopefully that will solve our problem with leaking outlets. Thanks again!

    • Todd Fratzel says:

      Alex – We’ve built quite a few homes with them and they can be a good solution for many of the open concept homes that don’t have room for duct work. I’ve had mine in my house 15 yrs and it works quite well. Good luck.

  8. Rachel says:

    We recently moved into our older home with a spacepak system and didn’t know about these two tips until now. We have water damage (no longer wet though) around the vent in our room and we have active water dripping from only one of the vents in our son’s room. The dripping started the first time we turned on the air this spring. How do we stop the drips now(I know how to prevent it next summer, but that doesn’t help with the dripping now)? Do I let it drip until all the water is done dripping and then just fix the ceiling?

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