Category: Radiant Heat

With the panels installed and the pex run, the next step is to prepare the radiant heat distribution in the mechanical room. Initially, I was under the impression that the system we had was all ready to accept the new zones, but it turns out that Lester didn’t really set this up for everything to just easily connect. Even though our plan for the radiant heating hasn’t changed, and our house still has the same number of floors and hence distribution zones, our existing system is only set up for three zones, and the controller is equipped for only one zone.

Unfortunately, this means that the heart of the system needs to be replaced with a larger unit. This is properly called a “hydraulic separator/manifold” but I refer to it as ‘the core’ because it’s easier and it sounds cool. Without getting too far into the weeds, the way our system works is the boiler has a supply and a return line that both connect to the core. The core in turn, has supplies and returns for each zone, or floor, of our house. It’s like an octopus reaching out to the rest of the house. On each floor there’s a supply and return manifold to distribute to individual loops on that floor.

A manifold just splits the flow of hot water from an inlet to several outlets with individual valves or, in the case of a return manifold, combines several inlets to one outlet. This way each floor has a water circuit to and from the boiler. Each zone has its own pump, and all but the hottest loop (the radiators in the attic) have mixing valves to adjust the temperature down from the boiler temp to something more suitable for that floor, since radiators generally run hotter than in-floor heat. Each zone will also have its own thermostat, so that they can call for heat individually.

I bought the same brand core as the old one, a Caleffi Hydrolink, just with more ports. I did this partly because the basement mixing valve is also made by Caleffi, and it’s sized to screw directly onto the supply and return ports. The only major change was that the new core has more ports, and one of the pairs of ports is on the bottom, which can go directly to the basement loop, and the other three sets on top can go to the first floor, second floor, and attic. I also bought fancy pre-built mixing valve and pump combo units to run the first and second floor units. I already had the parts for the attic from when we ran the radiators on the second floor.

The biggest concern is that it’s winter, and the system is running to keep the basement where we live warm. We need to shut off the heat, drain the water, completely take it apart and reconfigure it, hook the basement back up and hope nothing goes wrong, nothing leaks, and that we have heat when it’s all done. For a project like this, I called in Dean.

We got to work, and at first things mostly seemed to go smoothly. We got the system drained and the old core removed, but once we had the new core in place, we started running into some problems. First, there’s a port on the bottom that fills the system from the water supply that wasn’t in the same spot, so the plumbing didn’t line up. I hadn’t accounted for this, so I didn’t have the parts to adjust it. Before I ran to the store, though, we decided to see if everything else worked, and that’s when we discovered the bigger problem.

Caleffi apparently changed the spacing on their supply and return ports at some point in the last several years from 90mm to 120mm. This meant the Caleffi mixing valve for the basement loop that I already had didn’t fit on the new core. The new stuff fit, since it’s from the same model year or whatever. So I went to the store and picked up some brass fittings and we got it together as best we could.

Unfortunately, things didn’t line up very well, but it was getting late, so we made do and turned it on. For the next week the system had some slow leaks and the heat couldn’t quite get up to the thermostat even though it wasn’t all that cold outside. I came up with a new design, got some new pipe fittings, and started reconfiguring it yesterday. I discovered my new design still wouldn’t work, so I decided just to remove the mixing valve for now, and hooked up the system without it.

Since we’re not using the radiators right now anyway, the whole point of the mixing valves isn’t that important right now and we can decide if and when to change it later. The next steps will be connecting the pex lines that go to the other zones, running electrical to the new pumps, and replacing the controller.

I’ve spent the last few weekends on radiant. With the second floor panels installed, the next step was to run the Pex tubing. To do that you vacuum out the track, put down a bead of sealant that helps thermally connect the tubing to the track, then put the Pex tubing in. You can supposedly “walk it in” but in my experience you have to follow the tubing around with a rubber mallet and smack it into the track.

I got a couple loops of the second floor done during the week, then Aaron and David came back to help me finish the rest of the second floor loops. I had forgotten my careful previous planning when I bought the Pex, so I wound up using the wrong length coils on the second floor, which led to some unfortunate waste and a hasty order of additional tubing. With the loops down, we cut and fit plywood into all the remaining sections of the floor until everything was filled in.

During that week I got the rest of the joist tape up on the first floor ceiling. I didn’t want to drag the ladder around with the panels down. The next weekend I started clearing out the first floor and of course discovered a list of minor tasks that also needed to be done, like chiseling out a section of blocking that I had originally expected wouldn’t be an issue if we furred out the ceiling, which we wound up not doing. I also had to screw up additional 2x4s as nailing edges in the ceiling in a couple places.

I got the panels down in the back of the first floor, and the next day with Aaron and David’s help we go the rest down. Unfortunately, as we got to the front door, we hit two snags. First, we ran out of panels. I had ordered extra, but apparently not enough. I had a small stack of the return panels, but no more straights, so we counted up what we needed and I got those on order. Second, the subfloor by the front door was too high.

After all the time I spent leveling the joists and subfloor, this is frustrating. I calculated the height of the finished floor and positioned the door jamb accordingly, but somehow, there wasn’t enough room for the door sweep to clear the finished floor. Better to notice this before I put the radiant panels down, but still a headache.

Since we were out of panels anyway, I spent the week sorting out what to do, considering an engineered floor rather than hardwood, and eventually using a laser level to find that there was a distinct bow in the subfloor. I got out my power planer and a couple block planes and shaved down the subfloor until it was consistent, flat, and low enough for the door to clear it. Even so, I may need to replace the weather stripping.

With that done and the new panels arrived, Aaron and David came back this last weekend and we got the remaining panels and pex installed, but ran out of screws and pex before we could finish. We also got some of the plywood cut and fit, but not screwed down. To finally wrap this up I need more screws, more pex, more plywood, and probably one more weekend.

As I mentioned in my last post, we needed to make some progress on the radiant installation. We’re using in-floor radiant heating for the basement, first, and second floors, with radiators in the attic. The basement has tubing in the concrete slab, but on the first and second floors, this takes the form of plywood panels with aluminum backing. The first step is to design the layout, followed by cutting and fitting the panels to match that layout. The next steps are to apply a bead of caulk and run the pex tubing in the track, perform a pressure test, and then connect the manifold for each floor to the boiler in the basement mechanical room.

Sarah and I got started installing the radiant panels on the second floor. Then our nephews, Aaron and David, came down to pitch in. We managed to get all of the panels for the second floor installed, with only a couple small deviations from the plan where measurements were slightly off. We got into a routine where I measured and laid out panels, Aaron cut the needed pieces to length on the chop saw, and David followed us a room behind with collated screw gun.

I was pleased with how smoothly most of this process went, since usually we quickly discover unexpected complications. The trickiest part was where the lines converge at the manifold. the manufacturer recommends putting the converging pex lines into thinset or buying a fancy panel, but instead I used the router to add some additional tracks to the panels. There were also a couple of places where we needed the path needed to bend a bit to fit through a doorway. We have six lines running down the hallway (supply and return from three loops), which didn’t quite fit through the door.

We also had a couple of moments where we had to re-trace the path of the tubing a couple of times to be sure we had it right. The curved return track pieces can go either direction, so it’s not obvious how things will route with a glance. Sarah even brought up a ball of yarn to lay out in the track to keep things straight.

I’ve started filling in the plywood strips and we’ll get the tubing installed and pressure tested. We’re hoping to knock out the first floor this weekend, and hopefully get the system powered up and heating the house before too long. To do that we still have to reconfigure the core in the mechanical room, which will be a nerve-wracking undertaking, since we’ll lose heat during the process.

The Concrete guys poured the back porch footings, including the rebar. I was in meetings all day and couldn’t keep an eye on things, but when I went out there after a bit they left I noticed that the footings at the bottom of the stairs were six or eight inches above grade. Since the concrete was still wet, I grabbed a trowel and a level and scooped the sonotubes down to where they should be, level with grade. I also shoveled out the small section of sidewalk they had thoughtfully poured with extra, despite me asking them not to since we have pavers for that area. It’s been a couple of weeks and the dumpster is still in the back yard. Now he says tomorrow?

There’s been some further back and forth with the architect, expeditor, GC, porch contractor, and myself, trying to get permit moved along. I’m not sure how much longer it will drag out. On a positive note, I got an email today from the cabinet maker that price changes go into effect on January 1, but while most prices are going up, cherry wood prices are actually going down, so we may actually save money by waiting. I’m not feeling like we’ll need those cabinets before mid-February at our current rate of “progress”.

This past weekend I got to work on the radiator lines in the attic. I mounted the manifold in a closet and got the supply and return pex tubing installed to each of the radiator locations. There’s a bit to do yet. I installed framing in front that we’ll eventually mount the radiator to, but I still have to do the same in back. I also need to terminate all the lines with the stainless steel pipe I bought and then cap them so I can do a pressure test. I’m still waiting for some more parts to arrive before I can do the mechanical room work, but there’s plenty to do before then.

Meanwhile, I’m hoping that the GC can at least install the new house wrap, called “Blue Skin”, since I think some of the penetrations we’re waiting on will actually need to be set up after it’s installed because of the exterior insulation panels. He says tomorrow or Friday, which I take to mean Friday at the earliest.

They’re also going to ‘reset’ all the windows. I think I mentioned previously that all of the windows (except for the basement), which I installed using clips provided by the distributor, are installed incorrectly because the clips are actually for a completely different brand of window, which explains why they were such a pain to use. They are going to remove the clips, foam, and wrap around the windows and put them back in, but proud an inch or whatever so they’ll be flush with the exterior trim.

So! The next update should have some exciting progress.

The architect sent something back to the permit expeditor, so maybe that’s moving forward? I’m not sure. Something else to follow up on. We don’t have a new roof yet, but we still have a round 8″ hole in the roof that lets in the rain. Apparently the “Estate Gray” color is out of stock everywhere for the rest of the year. Instead we’re getting Onyx Black, which I don’t like as much, but hopefully at at least they can install it. I suspected when we had beautiful weather at the beginning of the month that it meant we weren’t getting our roof, and so it was. The weather has turned to cold and rainy, and even though we settled on the “in stock” color a week ago, no word yet as to when they’ll be putting it on.

I pinged the concrete guy since two weeks had turned to three. He said the end of this week as long as it didn’t rain. Well the end of the week is here, and it’s been rainy. Next week temperatures are dropping into the thirties; not great for pouring concrete. I haven’t heard back from him yet about a new date.

I asked the radiant company if there was any way to lower the cost (partially since they had originally quoted me much lower, suggesting such a thing was possible) and they never responded. I considered just putting down a half inch of plywood and heating with minisplits, but this is a feature of the house we’re really set on and don’t want to give up. If I had it to do over, I might have skipped it, but we’re committed at this point.

Instead, I started measuring, whiteboarding, planning, spreadsheeting, and SketchUping (I promise at least some of these are real verbs). The result is a complete hydronic radiant floor panel plan of equally-balanced loops each under the maximum length that all connect back to a central manifold.

There are apparently tools to help you do this, but I didn’t have them, so I made some formulas in Google Sheets, I fired up SketchUp, and I worked it out. It’s not the most elegant design, but it keeps the loops all the same size, which is the real trick. Since each floor is one temperature zone, it doesn’t especially matter if the loops are divided into discrete areas of the floor, just that they are the same size so that the manifold will flow evenly throughout.

After I worked out the first floor, the second floor came together more quickly, even though it’s quite a bit more complicated, since there are more rooms and less open space. The first step was to cover the house in rectangles that had a dimension divisible by 7″, the width of one panel. Cutting them down is certainly possible, but it will go much faster if I only do length cuts with the chop saw. The total square footage (actually I worked in square inchage) is divided to an ideal size for each loop. Then I come up with a layout plan that works. I had to work out ways to “borrow” from one loop to make another the right size, and then work back through the remaining adjacent loops to even everything out. If I came across something that changed the area to cover, everything had to be recalibrated. It was a bit of a pain.

After a few days I had all the loops designed. The next step was to measure up the total length of the straight and return sections to come up with exactly how much I needed to buy. I used another spreadsheet formula to confirm my panel coverage matched my area and saved myself a ton of errors. After finding the best deal online, paying the equivalent of a decent used compact car, and clicking the order button, I had a glass of scotch and wondered —not for the first time— about my life choices.

Just a couple of days later, I got a delivery notification and went out front to find the above box collection in the front yard. I’m not sure why they didn’t ring the doorbell, but as each box weighs about 60 lbs and it was a short enough time, none of it walked off (to my knowledge). We got it all inside and I’m now in the process of carting it up to the attic, one of the few places we’re not putting in-floor radiant heat and it hopefully won’t be in the way.

I emailed the radiant contractor (again) this time asking for a revised quote where they just install the pumps and controls. I have a miter saw, a collated screw gun, and the ability to follow directions, so I plan to take some time off work and put this stuff in myself. In theory, we’ll save a chunk of money in the process. If I’m lucky, it may all wind up costing around what they wanted to charge in the first place. We’ll see if they respond this time.

My preference is not to install the floor panels until the drywall is in to ensure it doesn’t get damaged, so that will be a while, especially at the pace things are going. I’ll still need the manifolds installed and the pex run through the walls, but I think I can manage that in a weekend or two. Wish me luck!